steel structure workshop lattice boom mobile crane repair

The steel structure workshop cranes the most tire cranes, crawler cranes and some truck crane and a dedicated mobile cranes are mounted lattice boom and top pulley block lifting device to change the position of the wire rope liter, in order to achieve the weights lift; longer be changed by changing the the truss arm's length and tilt angle to promote height and radius. Therefore, maintaining the integrity of the lattice boom is very important. These can cause varying degrees of lattice boom crane lifting heavy objects operating content diversity and a wide range of operating environments, as well as the level of the driver of the crane operation, and other reasons (and some illegal operations), injury, and even folding arm or casualties. 1 crack 
The tube truss arm steel pipe is welded at very prone to crack; carefully view the magnifying glass to carefully observe the necessary application. Based on our years of experience in the weld cracks at the very hour, it is necessary to conduct regular follow-up checks, pay close attention to the development and changes of the crack, in order to take timely measures. When the width of the crack is large enough to more than 1mm, it shall promptly repair welding. The specific method is to first crack at the original weld grinding, remove the number, as the case may be; then repair welding; the last renovation can.
Lattice boom pipe surface pit when the pit depth of the steel pipe of the arm thickness dimensions, and the deformation of the pits to reach 25mm in diameter (diameter of 2 ~ 5mm), and a ruler, if the position of the pit on the lattice boom steel surface can be measured in accordance with the method shown in Figure 1, the depth of the pit, the upcoming selecting steel balls into the pit, if the steel ball on the upper vertex just in contact with the lower edge of the rectangular, then we can depending Ball the diameter of the depth of the pit. If the position of the pit in the side surface of the steel pipe or below, can be first with butter sticking to the ball and then measured. Damage of such maintenance, available welded steel pipe of the same general material as the original steel reinforcement (see Figure 2), i.e. divided into two halves take a period of pipe along the centerline of its ends bevelled Stock weld perpendicular to the arm of the trussin the longitudinal direction of the steel pipe. Above the original lattice boom pipe to be welded at must be painted before welding polished clean, good preparation before welding single serious injury of steel pipe truss arm
When the the lattice boom steel structure workshop root steel surface damage is more serious, should be taken to remove the serious injury section of steel pipe, re-weld on a section of steel pipe processing, but must be coupled with a period of strengthening steel pipe inside the steel pipe. Section of the truss arm steel pipe has been removed so that before welding to strengthen steel pipe insertion to strengthen the steel pipe should be made of the same length of two sections (see Figure 3a and Figure 3b), and has threaded and welded two ways to connect . Strengthen the pipe L1 and L2 of the length to be removed than the lattice boom pipe section of short 20mm, and its outer diameter than lattice boom steel pipe inner diameter 20 to 40μm, to the reinforcing pipe in both can move within the lattice boom pipe is no longer loose. First strengthen steel pipe L1 and L2 respectively inserted into the the lattice boom steel pipe, and threaded connections to get up, and then tighten the two shaft shoulder by Yan, held pinpoint to strengthen steel pipe location, respectively the screw in position after, respectively, at the screw and two weld it either. The truss arm steel pipe weld to be made slant, its steel tube axis perpendicular angle between 10 ° ~ 30 °, such as damage to the tubes, should choose 10 °. At this point, and then carefully measuring the lattice boom pipe welding after the actual gap size, and with reference to the shape shown in Figure 2, the next section of steel pipe material, ends made 30 slant, sectioned along the middle of welding, in the notch of the lattice boom pipe; finishing, paint can 
Often detect the steel structure workshop arm section pin pin is also connected at the top of the arm section (hook block group), middle arm section (fixed) telescopic cylinders, the basis of arm section (turntable, luffing cylinder block rope pulley shaft), etc. should always check.When the wear amount of 5% of the original size, shall be promptly replaced. Check, also the tube lattice boom on a supporting point, remove a check one, and then install a by root check until the check is comple

The design of multi-layer floor lightsteel structure workshopic Comparison

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steel structure warehouse roof truss construction safety measures

steel structure warehouse installation. Construction method: the engineering steel structure installation, first of all review the axis and the basis of the top surface of the concrete foundation elevation points Lifting the first lifting of all steel columns, be corrected, fixed grout, in turn lifting the first floor to the five-story steel beams, with hanging with the adjustment, and then to install fixed, and finally lifting the roof support and purlin system. 2. Construction sequence: Live hoisting divided into two construction unit, each unit, respectively, to conduct an independent operating unit with a 50-ton crane, lifting by 8 axis to an axis from east to west, the unit using 50 tons crane by 9-axis to 15-axis from west to east, lifting, hoisting see hoisting plan in order. 3 pre-installation preparation. The the column bolt construction: review the construction of civil foundation column foot positioning axis, buried anchor bolts. To ensure accurate positioning of the anchor bolt, anchor bolts steel template hole sets fixed positioning, and repeatedly checking correct only after the pouring of concrete construction. Anchor bolts exposed part of the ground with plastic sheeting wrapped protection. . Preparation of installation plans and components supply plan, organize construction.

. Check the steel components: steel components factory should have factory certification, drawings the enumeration for review components before installing the components shipped in accordance with the order of installation to installation within not affect the installation conditions, try to members on the installation location below , in order to ensure ease of installation. ④. Standard section of the installation process ⑤. Installation quality standards for the project name to allow deviation the verticality single column buildings overall H/100, ≤ 10mm elevation Liang surface L/1000 and to ≤ 10mm capitals ≤ 5mm building height ± n (△ n + △ n + △ w) 4. Installation and construction process. Steel columns installed: the hoisting First determine the components hanging position, determine the banding method, good protective measures when lifting. After the lifting of the steel column, when the column foot away from the anchor bolts about 30-40CM righting the column foot mounting holes bolt, slow off the hook in place. After the beginning of the school is to be vertical deviation in 20MM, tighten the bolts, temporary fixed can be decoupled.


②. Steel girder lifting: steel girder lifting after the completion of the review in the pillars, and two points symmetrical lashing lifting in place to install steel beams when lifting. From the column datum 100MM steel girder lifting slowly slow in place until the steel beams hoisting butt adjustment correction, and then fixed connection. The steel steel structure warehouse lifting with hanging with theodolite correction, feel free to correct deviations. ③. Purlin installation wall: purlin sectional area is smaller, lighter weight, using a hook hanging method hoisting or lifting into pieces. The purlins correction pitch size and flatness. Pitch inspection sample rod along the purlin rod moves back and forth between any error, relax or tighten the bolts to be corrected. Flatness correction with cable and steel rule checks, and finally bolted. 5. The installation corrected ①. Steel columns correction: vertical steel columns degree correction using theodolite or hanging wire hammer test, using the jack when there is a deviation to be corrected, and elevation correction jacks on the base a little elevated, and then increase or decrease the pad thickness correction is correct, the column foot immediately after tight solid anchor bolts until the steel columns overall correction the correct pouring fine stone concrete fixed in the column under the soles of the feet. ②. The steel beams correction: steel beam axis and vertical degrees of measurement correction, correction jack and pour chain fixed immediately corrected. 6. The construction of high-strength bolts ①. High-strength bolts in the pre-construction material certificate (quality assurance) must retest must do before using. ②. High-strength bolts designated persons management safekeeping, shall not abandonment, not bruised bolts and contaminated dirt to prevent the torque coefficient changes during the installation process.


 ③. High-strength bolts to moisture, corrosion. ④. Application the bald the crowbar and rushed nails is up and down (or around) the connection plate screw holes so bolts can freely invest mounting bolts. ⑤. Connecting plate screw holes of error should check the discretion, if they are to adjust the screw holes invalid or the rest of the the local screw holes malposition, electric reamer or manual reamer punch. ⑥. Connected on the same surface, high strength bolts shall be invested in the same direction, should the day end after the installation of the high-strength bolts screwed completed. (B). Wall pressure type color plates installed. ①, pre-construction preparation prior to the construction and installation of steel sheeting envelope, ordered the construction drawings, design and construction personnel, technical training and production safety tests, and in accordance with the design documentation organization. ②, according to the file details check specifications and quantities of various types of materials, the damaged steel sheeting, flashings board shall promptly repair and replacement. ③, various types of construction equipment should be complete and normal operation. ④ review with steel sheeting construction installed on steel components installed accuracy, clear purlins installed weld drug skin and spatter, brushing and anti-rust paint anti-corrosion treatment. 2. Pressure-type color board construction process: the wallboard installed purlin position from one end to begin between the board and the board must clench, and then screw the wallboard seams waterproofing. Installation of steel sheeting, side laying side to adjust its position, while fixed. (C) floor bearing plate installed prior to the installation of the floor bearing plate construction, draw the corresponding row board diagram, in accordance with the construction drawings. Began laying steel sheeting along one end of the floor, while laying side to adjust its position, edge fixed. In case of the hole at first to install the pressure plate, then cutting the hole size based on the actual hole location. Stud connections combination connected from the floor beams with reinforced concrete floor, construction pull arc stud welding machine (Model: YD-200LS) and gun (Model: YS-223G), and use the deoxyribonucleic arc resistance thermal ceramics seat. Welding method: Turn the welder torch power the cylindrical pegs set in the torch, arc-proof seat and start welding torch, current fuse, arcing seat, the top tight base material by a short cylindrical pegs to a certain speed melting an end portion, the completion of the cutting power columnar stud welding is fixed on the base material. Stud welding inspection: columnar pegs the quality of hammering, supplemented by the appearance of surface inspection, take 1/500 per day production bending checks, no weld fracture considered qualified, such as weld cracks The peg sentence is scrapped, need to re-welding in the vicinity of a columnar nail as a supplement. VII. Quality assurance measures????? Company adhere to the "user is God, quality of life," the quality policy, seriously operation GB/T19002-9002 quality management model, quality supervision of the different types of work and every process, so that the construction process materials, semi-finished products, finished products quality under controlled conditions, so that the quality of the project are effectively guaranteed fundamentally.


Process quality assurance measures. Steel production: 1.1 This structure chosen steel factory certificate and the original data, and requirements into the plant must be after retest qualified, before use of steel. 1.2 good selection, use fully functional processing equipment, requiring factory production part of the H-beam flange plate using single-sided 45-degree bevel butt, web-sided 45-degree bevel miter. 1.3 Electrodes should have factory certification or material report, welding electrodes applied before drying oven for drying, use submerged arc wire and flux then selected must steel structure warehouse matched with the base metal. 1.4 Upon completion of the production of components of this steel in need of shot blasting, primed requirements rust within 24 hours, using stencilled primer, the paint film thickness to meet design requirements. 1.5 All operators must be performed in strict accordance with the technical, quality, safety tests, content requirements of welding personnel must be certified. 1.6 This steel structure steel requires welding of butt welds subject to ultrasonic flaw detection test, the detection level for the two. 1.7 steel structure to improve the accuracy of system holes hole drilling molded. Drill made of medium carbon steel is applied, shall be quenched the the jig bore diameter should be higher than the design aperture 0.3MM, jig thickness should not be too large, generally with 15MM. 1.8 In order to ensure the production of precision steel components material when preamplifier shrink the amount of pre-big bang may be depending on the size of the workpiece,

steel engineering the steel columns displacement solution

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steel pergolas process jingta

steel pergolas indicators: structural steel, mechanical indicators including the yield point, tensile strength, elongation, low temperature impact toughness. These indicators should be consistent with the design of steel structures "requirements, but low-temperature impact toughness only the structure may work only in a low temperature environment to test steel mechanical index determination is subject to "steel mechanical and process performance test sampling requirements" (GB2975-82)

(2) Steel Chemical composition: related to the workability of the steel, toughness, durability, etc., which is a limit content of the carbon content, the content of alloying elements, and sulfur, phosphorus and other impurity elements should comply with the specification (to GB222-84) requirements.

(3) process performance: process performance include weldability and workability weldability carbon content or carbon equivalent (low alloy steel), available weldability test identification. Processing performance through cold bending test to determine (GB232-88) as a standard.

(4) geometry deviation: Dimensions of steel (steel, section steel, round steel, steel pipe) with the theoretical size of the deviation must be within the range of allowable deviation value can refer to the national standard GB709-88, GB706-88, GB787-88 , GB978-88, GB707-88, GB816-87 like.

(5) contour deficiencies of steel: the steel surface may not have bubbles, scarring, crack, cracks, folds, inclusions and pressed into the oxide scale. These defects must be clear, the depth of the depression cleared the premises shall not be greater than the thickness of the steel negative deviation value. Further, when the steel material surface corrosion, pitting or scratches and other defects, the depth is not steel pergolasgreater than the negative deviation value of 1/2 of the thickness of the steel.

(6) mechanical cutting: cutting the use of mechanical force (shearing, sawing, grinding), mechanical shearing machine, sawing machine, grinder, more suited to a 12 ~ 16mm thick steel plates or profiles straight cutting.

(7) gas cutting: the use of oxygen - acetylene, propane, liquefied petroleum gas flame heated to melt the metal, used compressed air to blow the thawing of liquid metal, so the metal cut from suitable for curve cutting and multi-head cutting.)

(8) Plasma Cutting: using a plasma arc stream to achieve cutting, and suitable for the cutting of the refractory material such as stainless steel.

(9) Thermal shaping: refers to the steel is heated to a certain temperature and then processed. This method is suitable for forming the bending and correction can not be done at room temperature of the workpiece. Termination of the thermal processing temperature not be lower than 700 ° C. The heating temperature 200 ~ 300 ℃ steel blue brittle non-hammering and bending steel carbon content exceeds the range of the low-carbon steel generally can not be subjected to heat processing.

(10) cold-forming machining: is carried out at room temperature due to an external force beyond the requirements of permanent deformation of the material yield strength of the material generates or certain parts of the ultimate strength of the material for the material requirements and materials due to an external force beyond detachment. cold working has the material harden brittle trend, and thus the steel by heat treatment to restore the normal state or planing to cut off the hardening of more serious edge portion. cold working of carbon steel of the ambient temperature is below -16 ℃ not below -12 ℃ low-alloy steel, and shall not be processed.

Bending of (11): According to the design requirements, the process of processing equipment and tooling plate or section steel bending made certain shape formed suitable for sheet metal, small steel; bending suitable for thicker plates and more complex components, steel, bending temperature at 950 ~ 1100 ℃....

On the fire resistant design method based on the structural properties of the steel structure

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New technology for steel the high corrosion coating rust

steel structure engineering before painting rust prevailing traditional methods of mechanical shot blasting and sandblasting, hand electric grinding, stay in the steel surface more than rust, rust nuclear will continue to corrosion caused by iron and steel substrates, even if very clean rust new metal surface area increase, increased absorption of water, the possibility of corrosion caused by the impact of the environmental corrosion medium. In this case, the paint coating often fail to achieve the anti-corrosion of years, even with long-term corrosion paint system construction, rust-proof time will thus be greatly reduced. Therefore, paint anti-corrosion, the key is to no longer exist to continue rusty condition of the metal surface. This article describes the structural steel engineering high corrosion coating process, mainly the main line to the patented technology, National Key New Products - JZ. CXFX-N to turn rust Vajra new material applications based on nearly two years of experience in the engineering application summary, focusing on rust years different methods of steel metal surface rust, paint coating brought before painting process changes the intrinsic quality to improve, extend, and the construction is simple, flexible application, reduce costs, save energy and reduce Pai and other interests. Innovative materials brings the advanced nature of the technology, has great application value.
Turn rust Diamond JZ.CXFX-N About JZ.CXFX-N turn rust Diamond the special function varnish of a thick liquid processing new materials as steel anti-corrosion coating surface before taking effect only for rust has a dual function of rust and rust. Coated on the surface of the corrosion of the steel member can be directly through the brush, wiping, spraying, etc. After 0.5-1 hours at room temperature, the surface of the steel rust is transformed to produce a gray-black rust substance, closely attached to the steel structure (adhesion 1) formation of high corrosion film, as the underlying can effectively improve the quality of the anti-corrosion coating paint. Dense (the film thickness of approximately half of the original thickness of the rust layer is typically a few microns, cured completely after 22 hours), insulated, completely blocked the conditions for further rust formation, and surface roughness, an indoor rust up to one year as paint underlying can significantly improve the the painting rust prevention of long-term, strengthen the capacity of heavy-duty. Good turn rust Diamond JZ.CXFX-N experience supporting the use of various paint system, with binding force, due to its rust completely rust-proof and strong, to extend all kinds of paint system preservative time limit for ordinary Antirust performance is particularly evident in the case of the construction according to specifications can be improved more than 1 times the corrosion cycle. Due to the above performance of the new materials, so that the existing problems can be solved in steel production and processing, and thus has the following construction advantages:
(1), GB8923-88 "before painting steel surface Rust grades and preparation level" standard, even if the D grade rusting steel without shot blasting, sand-blasting, can be directly spray, brush turn rust Diamond JZ.CXFX -N to achieve the purpose of the turn rust rust rust grades equivalent Sa2.5, St3 level. This has brought great convenience to the field construction of large components, construct complex node.

(2), factory production of large, complex steel components, cutting, shot blasting, welding and other processes that take a week or even a half months before entering the paint process, throw a net steel surface secondary corrosion, a direct result of The epoxy primer binding is not strong, bubbling quality defects. The use of the material rust, rust-proof function, you can completely overcome this problem. (3), hot ligation and heavy-duty steel work surface, usually covered with a layer thick-mm level and very dense and hard steel blue oxide (chemical composition Fe3O4), shot blasting sand-blasting is extremely difficult to completely clean. Fe3O4 the naturally occurring form of iron ore, stable, but after contact with air, it will slowly loose red rust oxidation generated (chemical composition of Fe2O3). Turn rust Diamond JZ.CXFX-N oxide coating, anti-rust film steel structure can be completely isolated from the air, the reach of anti-corrosion purposes. (4), fill in the steel construction process coated with rust, the late stage of the maintenance process rust off patent leather, simple clean up oil, grime, brushing the material directly, table dry after 1-2 hours can brushing paint. The material does not damage the paint, the old paint surface binding force after brushing with the new paint better.
(5), JZ.CXFX-N turn rust King Kong use the same paint, construction specification can refer to "steel anti-corrosion coating process standards (508-1996) in paint construction requirements. Due to the viscosity of the material is much smaller than the paint, and only need to steel surface wetting can, therefore, 1 kg of coverage up to 40 square meters, the material consumption is about 1/8 of the paint. (6), JZ.CXFX-N turn rust Vajra non-toxic, odorless, and does not pollute the environment, label applicable to all types of steel, cast iron, ferroalloy, only its corrosion products play a role in non-destructive steel matrix microstructure of steel no injury, Thus, the steel does not affect the mechanical properties (tensile strength, elongation, yield point, cold bending properties, impact toughness).

Discussion on construction steel pergolas fire

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On-site fabrication and installation of steel structure color steel sandwich panel

Installed at the processing site selection of colored steel sandwich plate deformation capacity of its wind should be considered in addition to considering the decorative effect. The wall board is mainly exposed to wind load deformation resistance to wind loads capability depends on the thickness of the plate, and the fulcrum spacing and support conditions. If the span is too large, colored steel sandwich board is easy to produce wind load effect Deflection impact curtain overall effect. If designed properly, but also left on the plate irreversible plastic deformation. Color steel sandwich panel, color steel sandwich panel processing steel structure and handling Caigang of sandwich panels before installation should be possible to retain the factory packaging, should be kept in indoor. Lifting equipment and heavy objects such as piling up in the outdoors, stacked locations should be smooth, no water and over should have after the board with skids booster 20cm, soft material to be placed between the board and the board, the same model The board put together each pile board should be easy to identify the board type label and cover the rain tarpaulin. Stacking space should be set the temporary Weidang, to avoid unnecessary damage to personnel moving around causing plate.

The installation of the curtain wall panel color steel sandwich panel installation general activities scaffolding, ensure the carrying capacity of the construction scaffolding, but also take into account: (1) curtain wall surface, between the work surface with the axis distance; (2) cross-references surface find the spacing and location of the control point, resistance Note TONGSHI; (3) control the reference plane to identify the installation angle of the pitch; the level difference between the (4), with the control elevation; (5) with the building vertical spacing and with each floor spacing. The carrier sheet should be two at the same time lifted, so as not to damage the surface oxide film or coating. Installing wall panels, each time only lifting the one plate, and provided by the manufacturer should be used dedicated jig in wallboard length direction of the stitching, at 2:00 lifting wallboard.

Slowly lifting process, use wind cord of control, to avoid and installed wallboard bump, scaffolding protruding parts with soft material wrapped. Sandwich panels fixed mainly two ways: one is the self-tapping screws through the wallboard directly fixed to the structure of the wall times. Another approach is a self-tapping screw through the connection member is indirectly connected to the secondary structure and wall. Curtain wall panel installation precision: the verticality of the facade 2mm, 3mm surface roughness, flatness of joints 0.5mm. Installation according to the factory to provide the technical manual strictly enforced. Weather rubber used in the fixed income side panels and flashings board with weather rubber caulking seal to prevent gas permeability and rainwater leaking. Caulking weather rubber plastic injection should pay attention to: (1) the gap between the fully clean plate to ensure that the adhesive surface clean and dry; (2) to adjust the depth of the seam, avoid trilateral dipping seam filled PVC foam materials (round bar); (3) dispensing glue seam should smooth the surface, remove the excess glue; (4) Note dispensing conservation, the glue is not completely hardened before, do not dust and planning injury. After the end of the installation closeout color steel sandwich panel curtain wall installation, top to bottom, layer by layer to tear up the the wallboard surface of protection film layer synchronization Dismantling. steel structure should pay attention to protect the wallboard, not bumps, scratches, and finally completed the entire curtain wall works. The impact of construction to the curtain wall and curtain wall components such as surface decoration adhesive material should be immediately removed.

Curtain wall project after the installation is complete, from top to bottom cleaning solutions should be developed to prevent surface decoration exception occurs. Neutral detergent for cleaning the wall panels should be tested to prove that no corrosion on the the wallboard surface of coating. Mild detergent should be washed with water. Color steel sandwich panel curtain wall maintenance and maintenance of the curtain wall system must carry out regular cleaning and maintenance, generally at least once a year for a routine check, and to identify potential problems and to maintain the appearance of its surface and extend the service life. Cleaning the surface must be careful not to scratch the surface occurs phenomenon, avoid the use of bleaching ingredients and the abrasive-containing washing liquid, steel balls, grinding tools, etc., end washing to use clean water from top to bottom to rinse the surface. If the wall surface is damaged, should be promptly repaired, the underlying processing by the underlying cleaning, except oil patch at the top of defects,  the find equal process in steel structure to ensure the top of the formation, the putty should be at least full scraping 2 times. Brushing coating brush primer before, the topcoat should brush at least 2 times. The complex fill putty and sanded processing should be performed after each pass topcoat refers dry, and wipe with a damp cloth buoyancy on the film, then brushing under 1 times. Coating trim include polished, polishing and other processes, surface water should be used sandpaper, polishing clean soft cloth dipped in sand wax should be used to wipe the surface polished.

The course of development of the steel building system
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The VSR future and its effect-jingta

Vibration Stress Relief future and it is the effect of VSR can be regarded as an additional stress in the form of a cyclic load applied to the parts. Known engineering materials used is not an ideal elastic body, the interior of the existence of different types of micro-defects, the cast iron is the existence of a large number of shapes of cutting the metal body of the graphite.Therefore whether it is steel, cast iron or other metal, microscopic defects in the vicinity there are varying degrees of stress concentration. When subjected to vibration, the alternating stress applied to the parts on the parts of the residual stress is superimposed. When stress superposition results reach a certain value, the most serious part of the stress concentration will exceed the yield limit of the material is plastically deformed. This plastic deformation reduced there residual stress peak and reinforced metal matrix. 

Then, vibration in others stress concentrated to produce the same effect on the more serious part, until the vibration of additional stress and residual stress superimposed algebra and can not cause any plastic deformation of the parts of the date at this time, will no longer generated to eliminate vibration and homogenized role of residual stress and strengthen the metal. Less investment in the production cycle is short and easy to use, emissions and radiation pollution save energyVibration Stress Relief reduce the cost of research and practical application proved that the the VSR workpiece aging effect in coal, heavy oil or gas heat aging furnace, basic and electric furnace similar aging effects, not only because the VSR overcome the uneven heat aging furnace caused to eliminate stress non-uniformity of the problem, and to avoid the the workpiece heating and reduce the impact of its resistance to deformation, so the general processing of the workpiece by the VSR than the average The dimensional stability of the thermal aging treatment of the workpiece can be increased above 30%. VSR equipment technology is not the venue, with the people improve environmental requirements, thermal aging furnaces flue gas, dust, slag problems have restricted VSR can completely avoid VSR technology countries have been to promote the cause Blind hole for Residual Welding Stress Elimination http://steelpergolas.blogspot.com/2012/12/blind-hole-for-residual-welding-stress.html 

Technology and the principle of Stress Detector voltage tester

Resistance DT267A-4B-type safety performance of the technology and the principle of the technology and the principle of withstanding voltage tester voltage tester voltage tester resistance tester is generally referred to as a pressure tester, also known as electrical insulation strength tester called a dielectric strength test Miriam, also known as the dielectric breakdown of the device, the dielectric strength tester, high pressure experimental instrument, high voltage breakdown devices, pressure tester. A Stress Detector AC or DC high voltage is applied to the electrical live parts and live parts (usually the shell) to check electrical insulation materials can withstand the test pressure capacity. Appliances in the long-term work, not only to withstand the rated working voltage, but also to withstand the operation caused several times higher than the rated working voltage over a short time voltage is applied (the overvoltage values ​​may be higher than the value of the rated working voltage) .


The effect of these voltages, the internal structure of the electrical insulating material is to be changed. When overvoltage strength reaches a certain value, the material insulation breakdown, electrical appliances will not run properly, the operator may get an electric shock, endangering personal safety. Electrical safety testing indicators include AC / DC voltage, insulation resistance, leakage current, grounding resistance. AC / DC voltage test is used to test the electrical safety performance of products under actual working conditions, is one of the important indicators of the testing equipment electrical safety performance. Withstanding voltage tester currently seen on the market using the GB4706 (equivalent IEC1010) standard, the use of more desktop structure of a single test indicator test instrument, can not meet the demand of user needs a comprehensive test of the Multiple Indicator; and resistance on the market pressure tester to use more traditional Stress Detector of testing, test accuracy is not high, the use of technology and performance gap with foreign advanced level, can not fully meet the needs of the current development of electrical safety testing. Therefore in line with the latest international standards, the use of advanced technology and better performance withstand voltage test system has an important significance.

Withstanding voltage tester structure and composition DT267AC programmed insulation withstand voltage tester voltage tester resistance technology and principle
(1) step-up part of the regulating transformers, step-up transformer and boost the power is turned on and composed of cut-off switch. 220V voltage by turning the cut-off switch to the regulating transformers regulating transformer output connected to a step-up transformer. The user simply adjusting the regulator can control the output voltage of the boosting transformer.
(2) the control part of the current sampling time circuit, the alarm circuit components. The control section when the start signal, the instrument immediately switched boost power. Upon receipt of the measured loop current exceeds a set value and audible alarm and boost circuit immediately cut off the power supply. When received reset or time to cut off the signal boost circuit power supply.
(3) circuit output voltage value of the display shows the step-up transformer. The display by the part of the current value of the current sampling time and the circuit time value is generally countdown.
(4) above is composed of the resistance of the conventional structure of the voltage tester. Computer technology, the rapid development of electronic technology and monolithic; programmed withstanding voltage tester developed rapidly the past few years, the programmed pressure instrument with traditional pressure instrument boost part. Programmable voltage meter high voltage boost is not adjusted by the regulator through the mains, but is controlled by the single-chip computer generates a 50Hz or 60Hz sine wave signal and then through a power amplifier circuit amplifies boost the output voltage value from a single the piece computer control, test security, test accuracy and convenience of the test is much higher than traditional pressure instrument gradually become the first choice of the user, and is recognized by more and more users.
Stress Detector technical understanding of the status of
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Ultra light steel structure housing the four performance

Performance of four large housing &nbsp light steel structure applied in the workshop, high-rise residential development like a raging fire, high-speed development has also led to the development of light steel structure residence in the underlying application, applied to real estate residential steel structure can be called ultra light steel structure system.Ultra light steel structure housing the main steel structure of light-weight steel structure with less than 2MM, only the following 1MM, light steel structurebut ultra light steel structure housing the intensity is much higher than that of traditional steel.Ultra light steel structure housing combines all the advantages of light steel structure, on this basis for residential bottom characteristics will be the bottom housing construction system is more and more sophisticated, intelligent, light.The following is ultra light steel structure housing the superiority of the four major aspects of performance, seismic, wind resistance, high reliability and excellent physical and mechanical properties of the steel, the ultra light steel structure housing with integral stiffness, component high strength, lightweight structure characteristics, in the earthquake, hurricane and other rare disasters under the performance is far superior to the other form of residential structure.On soft soil area, ultra light steel structure housing can reduce infrastructure costs, and reduce the probability of occurrence of uneven settlement.Ultra light steel structure housing the precise design and analysis, so that the steel structure residential building structure reliability is superior to brick concrete housing.Performance two, anti-corrosion, fire protection, durable super light steel structure housing the corrosion of galvanized steel use, greatly enhancing the construction of the main structure of the anti-corrosion durability, reasonable construction measures can ensure that the steel structure fireproof performance; structure creep, damp and suffered from termite, rats and other pests will not in steel structure residence appear to.The performance of light steel structurethree, heat insulation, sound insulation, energy-saving composite wall structure of light steel structure housing guarantee for insulation, moisture-proof, insulation housing needs.The use of hollow glass so that the sound insulation index of 40 weighted decibels, in addition to greatly reduce noise pollution, can save a lot of energy.The performance of four, can "free space" residential steel lightweight, high-strength, ultra light steel structure housing system flexible choice for residential space combination provides the greatest degree of freedom.An ultra light steel structure housing can provide large space, at the same time the architect can not rigidly adhere to the bearing wall position, according to the need of design free layout of the functional space.
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On the characteristics of vibration aging equipment in the wind power industry application

Welding Stress Eliminationin the wind power industry application situation for everybody below about vibration aging equipment in the wind power industry application with the vibration aging equipment development, wind energy market has developed rapidly.China's wind energy reserves are large, wide distribution, development uses latent capacity tremendous.As energy saving and environmental protection of new energy, wind power industry to win a historic opportunity for development, in recent years, the rapid development momentum, China wind power industry development prospects, is expected in the future for a long period of time will maintain high speed development.As wind power manufacturers, in the face of a large number of problems of welding, and after welding stress need corresponding means to effectively solve the aging.Due to wind power equipment of welded structures, mostly size was relatively large, complex structure, so if the use of heat treatment way, obviously not suitable for.Vibration aging equipment as a convenient, efficient, energy-saving, low cost effectiveness for a given period of time, gradually become wind power manufacturers choice.Vibration aging equipment is for the use of units to create a huge economic and social benefits.Therefore, the above all is the story of the vibration aging equipment in the wind power industry, application situation, hope that we grasp.


The vibration aging equipment features of vibration aging equipment has been widely used in various fields, banned the thermal aging, need not wait for a long time and heavy equipment.Compared with thermal ageing VSR, the main features are: A, mechanical industry performance, vibration aging main scope of application is the development of machinery industry, eliminate the workpiece in the production of machinery in the process of deriving the stress and residual force, after vibration processing component of its Welding Stress Eliminationresidual stress can be eliminated, high stress the force area to eliminate than low stress zone.It can be improved by the use of strength and fatigue life, to reduce the stress corrosion.At the same time can prevent the workpiece in the completion of the production process of crack and deformation.Two, strong applicability, no matter what the machine can be used freely.From the thermal aging of heavy equipment and not applicable.Vibration aging equipment can be simple to move, it is not affected by the size of the members and the limitation of material, from dozens of kilograms to hundreds of tons of component can be used in the vibration aging technology.Three, reduce the cost of investment, vibration aging compared to thermal aging time should be much shorter, whether in manpower and material resources are a reduction in investment.Vibration aging aging generally completed in about half an hour.Compared with the vibration aging, can save resources, especially in some large mechanical industry applications, greatly reflect the vibration aging equipment cost.
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What is the biggest drawback of the cast-in-place reinforced concrete structure building?

The reinforced concrete structure has the following major shortcomings:
(1) Since the material. The density of gravity of the reinforced concrete is approximately 25kN / m ^ 3, severe than masonry and wood. Although severe than steel, but the larger the cross-sectional dimension of the structure, and thus its own weight far exceeds the same span or height of the weight of steel.
(2) poor crack resistance. As mentioned earlier, the tensile strength of the concrete is very low, therefore, ordinary reinforced concrete structure with cracks frequently. Although the presence of the cracks does not necessarily mean that a structure is destroyed, but it affects the durability and aesthetics of the structure. When the cracks in larger quantities and to carry out a wide, also inflicts a sense of insecurity. (3) the nature brittle. Increase the brittleness of concrete with the improvement of concrete strength grade. In summary is not difficult to see that the reinforced concrete structure strengths outweigh its shortcomings. Moreover, people have developed many effective measures to overcome its shortcomings. For example, in order to overcome the major drawback of reinforced concrete since have developed a lot of light weight, high strength concrete and high strength steel. In order to overcome the shortcomings of ordinary reinforced concrete is susceptible to cracking, prestress it. In order to overcome the brittleness of concrete, concrete mixed fibers made ​​of fiber reinforced concrete.

Antibacterial agents to improve the life of water-based metalworking fluids

Laboratory ventilation device to simulate the field conditions, the effects of different antimicrobial agents antimicrobial properties, the results show that a single antimicrobial agent is difficult to both bacteria and fungi from the good inhibition composite antibacterial agents against bacteria and fungi have a good inhibitory effect. Meanwhile, in multi-machine composite antibacterial agents on-site application test, the results showed that the composite antibacterial agent to extend the life of the emulsion and synthetic fluids are up to ten times more. 1 Introduction aqueous metal working fluids (including emulsion, and synthetic fluids) are widely used in the machining industry, it has a good cooling performance and cleaning performance, and low cost, but also easy spoilage, such as shorter life shortcomings. Spoilage is results blooms of bacteria, fungi and other microbes in the water. The microbial blooms undermine the stability of the emulsion, the emulsion reduced use of performance: also lead to a decrease in pH, resulting in corrosion: also have an adverse impact on the operator, such as an unpleasant smell, irritate the skin, allergic reactions . The antimicrobial agent is added to prevent spoilage, improve the water-based metalworking fluid life. Abroad in the Water Fund antimicrobial agent commonly used in metalworking fluids, varieties of dozens of antibacterial agents. The domestic use of antimicrobial agents is still not widespread, the service life of some of the processing liquid in the summer only a week or so. Although many varieties of antibacterial agents used in other areas, but most of them can not be used for processing liquid. The antibacterial agent used for the machining liquid should have the following characteristics: (1) better chemical and physical compatibility with the processing liquid: (2) a degree of stability, in the long period of time from the antibacterial effect: (3) inhibition of bacteria and fungi have a better: (4) low toxicity: (5) an acceptable cost. In this paper, laboratory ventilation device to simulate field conditions of use regularly to detect bacteria and fungi and pH, and record the change in appearance of the processing solution, the screening of various antibacterial agents.Field application test of the composite antibacterial agent while still on multiple machines, regular monitoring of bacteria and fungi, the pH value, the change in appearance and corrosion performance. 2 test laboratory test this integrated foreign representative test methods: each cycle of five days of the sample assessed through air, stop gas two days, made periodically added to the scene and cultured bacteria.Bacteria, fungi, and pH were measured after the end of each cycle. Deterioration of the sample indicators: total bacterial count> 107 / ml, fungi total number of> 103 / ml.Laboratory test conditions: (1): comply with the requirements of the biological tests. (2) Equipment: ventilation apparatus, pH meter, incubator, colony counter and inoculation test bench. (3) Metalworking Fluids: The hardness of 100 ~ 150mg / L (calcium carbonate) was diluted with water the emulsion concentrate, and the dilution factor of 20.(4) assessment of samples: in the metalworking fluid, adding a variety of antimicrobial agents, as shown in Table 1. (5) Strain: obtained from the scene of the deterioration of the metalworking fluid, and cultured in the above-mentioned metal processing liquid to the total bacterial count> 5 × 108 / ml, fungi total number of> 104 / ml in. Field application test field application testing in the summer of 1997 in Beijing First Machine Tool Plant, composite antibacterial agent dose of 0.10% is added to the emulsion and synthetic fluids, two grinders use test, regular monitoring of bacterial and The number of fungi, pH value, the appearance of change and anti-rust properties (a cast iron, 35 ± 2 ℃, 48h, monolithic). Table 1 assessment sample numbers type of antimicrobial agent concentration (%) Remarks a nitrogen-containing heterocyclic compounds Ⅰ 0.07 reference to the manufacturer's recommended concentration of nitrogen-containing heterocyclic compounds Ⅰ 0.103 nitrogenous heterocyclic compounds Ⅱ 0.134 nitrogen-containing heterocyclic compounds II 0 .195 0.0166 composite antibacterial agent sulfur compounds 0.100.07% nitrogen-containing heterocyclic compounds Ⅰ +0.016% sulfur compounds + small amount of stability synergist 7 - pure metalworking fluids test results 1) the antibacterial properties of the antimicrobial agent antibacterial agents listed in Table 1 the antibacterial effects of the test, the test results are shown in Table 2. Bacteria and fungi from Table 2 Total number of metamorphic term, the sample No. 7 does not add an antibacterial agent against bacteria and fungi have no inhibition: have some inhibitory effect of various antibacterial agents against bacteria or fungi.Wherein: (1) 1 to 4, samples are fungi first exceeds the deterioration indicator described nitrogen-containing heterocyclic compounds I and II inhibition superior to the inhibition of fungi of bacteria: and 2,4 sample No. metamorphic respectively the high dose of the antibacterial agent in the dose range selected its antibacterial effect better than the sample length 1,3. (2) Sample No. 5 is a bacteria exceeds deterioration indicator, no significant growth of fungi in six weeks, this sulfur-containing compound will be described have a good inhibitory effect on fungi, while the inhibition of bacteria is not obvious. (3) 6 samples after up to 20 weeks of the trial is still degenerate. Obviously, aza ring compounds I and sulfur compounds composite using a significant synergistic effect, have excellent inhibitory effect on bacteria and fungi. Table 2 laboratory test results Number assessment project beginning point one week Wednesday, Thursday, Friday and Saturday 20 week seven weeks and eight weeks 10 weeks 22 eleven weeks weeks weeks metamorphic phase 1 the total number of bacteria,

Notice the use of refrigerator car

The so-called lightweight cars, is the use of scientific methods and means to optimize the design of automobile products, to ensure that the automobile integrated performance index under the premise, through the use of new materials, as far as possible to reduce the weight of its own products, to achieve weight loss, consumption, environmental protection, safety comprehensive target.Research shows, vehicle fuel consumption to about 60% motor vehicle, automotive quality every reduce 100kg, every kilometer fuel consumption will be reduced from 0.4L to 0.8L, CO2 emissions will be reduced.Fuel efficiency, reduced by means of the car's fuel consumption and emissions, improving the environment for human survival.At the same time automobile lightweight but also to improve the vehicle performance, in the same output power, the lighter car for the engine is lighter load, vehicle handling stability is improved.So to reduce automobile weight to reduce engine power and reduce the total vehicle weight has a dual effect.The national standard of vehicle design are strictly stipulated, in particular the axle load and the total mass limit.For oil tank cars, tank weight accounted for a larger proportion of vehicle weight, reduce body weight has become the focus of attention of the enterprise.Because the aluminum proportion is approximately 1/3 steel, aluminum alloy is considered as the ideal materials for lightweight of automobile.In recent years, the developed countries in Europe and America, the use of aluminum alloy produced by the liquid tank has been very common.But in our country usually use steel tank.Because the steel tank weight greatly, virtually increased fuel consumption, the transportation cost is greatly improved.Aluminum alloy besides being light, it also has excellent resistance to corrosion.And also made of steel parts, aluminum and aluminum alloy parts made use of higher value.95% aluminum alloy can achieve reuse.If the use of aluminum alloy oil tank car tank body, can greatly reduce the vehicle weight, save fuel oil, reduce the waste of energy.Hubei power company engineering and technical personnel, after two years of research, the existing steel tank for structural analysis and optimization, in ensure bearing capacity and reliability to reduce its quality; through the use of light materials or modern composite materials such as low density material to replace the existing steel materials, developed a lightweight aluminum alloy oil tank car, achieve the purpose of the tank body lightweight.The car reached the main performance indicators: aluminum alloy oil tank car in can realize lightweight foundation, tank anticorrosion performance and stainless steel cans, cans of strength based on the optimized design to meet the requirements.Through reliability road test and the tank body sealing test.Aluminum alloy oil tank car, application of aluminum alloy to make the tank, not only reduces the quality of vehicle, the original use of steel making body weight is 8850kg, now made of aluminum alloy body, only 7570kg.So every 100 km fuel savings of more than 4L.In the improvement of automobile dynamic characteristics at the same time, pollutant emission is reduced by more than 10%.The technology leader in the domestic, Europe and the United States and technical level.

Copy copy method: first the ground sampling method are assembled

into a single structure, and position of welding,


Then turned as the replication membranes, in which a single structure assembly.Applicable to cross section are symmetrical truss structure.


(21) vertically installed: according to the characteristic of component parts and stable position, choose a top-down or bottom-up assembly, adapted to be placed stably, height is not the structure.(22) lying supine position: component placement assembly.For section but not long slender member.(23) fetal membrane assembly of law: the component parts in fetal membranes positioned in its assembled position assembly.Used in the manufacture of components of large quantities of products with high accuracy.(24): using electric arc welding electrode and the work piece the electric arc generated between hot metal fusion process is called electric arc welding.Electric arc welding manual welding, automatic welding, automatic welding and gas welding of.(25): resistance welding current through contact with two welding parts, the contact resistance maximum current through the high temperature produced, so that the material in a molten state, the pressure, and fusion.Generally used for butt welding steel plate or spot welding.(26): electroslag welding current through the slag produced by thermal resistance to molten metal welding.As for box column and Liang Gang with the column connecting beam upper and lower flange stiffening plate welding.(27) manual welding: all manual electric arc welding, low efficiency, quality to rely on their own, poor stability, but flexible, suitable for short and complicated weld or site welding.(28) automatic submerged arc welding: welding arc buried in the welding powder below, the mechanical automatic sprinkling and sends the mobile welding wire flux.For a longer weld.Good welding quality, high efficiency.(29): CO2 or gas protection welding argon arc welding molten metal, the wire and gas sending are automatic, only manually move the torch.Is a semi-automatic welding, good welding quality, high efficiency.(30): shot blasting the particle diameter of 0.8 ～ 2.0mm steel by throwing machine impeller suction impeller tip in the center, directional high-speed throw, at the need for anti-corrosion treatment of the surface of steel structure, to achieve mechanical descaling purposes. This method high rust removing efficiency, low cost, less pollution.Anticorrosive measures of the steel structure (1): corrosion resistance of weathering steel is better than that of the general structural steel steel called weathering steel, generally containing phosphorus, copper, nickel, chromium, titanium and other metal, the metal surface layer of protection, in order to improve the corrosion resistance of.Low temperature impact toughness than the general structural steel.Standard for welded structure for "steel" (GB4172-84).(2): galvanized hot-dip galvanizing is rust steel immersed in 600 ℃ high temperature melting zinc liquid, so that the steel member is attached to the surface of zinc coating, zinc layer thickness on the 5mm plate shall be not less than 65 μ m, the plate is not less than 86 μ M.In order to anticorrosion aim.This method has the advantages of durability life long, the production of the high degree of industrialization, stable quality.It was heavily used by atmospheric corrosion is serious and difficult to repair for outdoor steel structure.Such as a large number of transmission tower, communication tower.In recent years, the emergence of a large number of light steel structure system of steel plate and so on.More also use hot-dip galvanized anticorrosion.The first process of hot dip galvanizing is pickling, and then is washed.The two processes are not completely to stay hidden corrosion.So we must completely.Steel structure for the designers, should avoid to design a joint surface component, so as to avoid the abutted surface cracks in pickling is not complete or acid wash net.Cause the galvanized surface of yellow water flow phenomenon.Hot dip galvanizing is done at high temperature.The tubular member open at both ends should be left to their.If the ends are closed will cause the air inside the tube expansion and the head plate burst, thereby causing safety accidents.

How to prevent local deformation in steel welding

1, the steel structure engineering design as much as possible to make the workpiece stiffness of the various parts and weld evenly arranged, symmetrical set weld to reduce cross intensive weld.
 2, large parts such as shape asymmetry, a small group of components should be welded correction of deformed during assembly welding, to reduce the overall deformation.
Workpiece welding should often flip deformation cancel each other.
 4, for easy to produce the angular distortion of parts after welding in the weld before pre-deformation treatment, such as steel v-shaped groove butt, before welding should interface appropriate booster This enables welding after flattening.
 5, the steel company to develop a reasonable welding sequence to minimize distortion. Minor weld first welding the main weld welding, the the first welding symmetric parts of the weld after welding asymmetric welds, welding contraction after a small amount of the first contraction welding large weld weld before welding butt weld The solder fillet weld.
6, workpiece size weld using segmented, stratified, intermittent welding, and controlling the current, speed, direction.
7, hand soldering longer weld should be segmented the intermittent welding method, by the middle of the workpiece to the two retired welding, welding personnel in responding to that scattered arrangement to avoid deformation caused by heat concentrated. 8, steel structure plant outside welding reinforcement pieces increases the rigidity of the workpiece to limit the welding deformation stiffeners position should be located in the opposite of shrinkage stress.

Test material substrate selection model: commonly used in recent years quality chromium steel

(2) paint:

1 precoating primer: selection of magnet epoxy ester antirust paint.Because after the pretreatment of steel on the set of welding steel structure, need after welding and cutting, grinding and other processes, the paint layer surface is inevitably there are a lot of defects such as scratches and fall off, so the selection of current locomotive steel structure commonly used high temperature, heating influence is small, anti-corrosion properties of strong magnets epoxy ester antirust paint the precoating primer for steel surfaces.

2 primer: phosphoric acid polyurethane primer.Steel structure welding after forming, in order to repair its surface defects, but also for the next step of putty or coated with paint to prepare, general need for steel structure and then spray 1 times primer.The primer and next process with putty and overcoatability.Verified by the production of zinc phosphate primer, polyurethane can completely meet the requirements.

4.2 test procedure

The 4.2.1 sample surface treatment model will be divided into A, B two group, the 12 block, wherein the group A by sandblasting treatment, group B sandblasted, with only 240# emery cloth polishing.With organic solvent two groups of sample surface clean, cold wind blowing, placed in a dryer.

The preparation of A film 4.2.2 model, B model of the group take 6, spraying 1 zinc phosphate primer for polyurethane, drying; and A, B group and the other 6 examples, sprayed with 1 magnets epoxy ester antirust paint, drying the 48h, and then spraying 1 zinc phosphate primer for polyurethane, drying.

Performance test of 4.2.3 (1) on the preparation of good film group A, group B model, respectively, thickness measurement, then do the following properties: 1 test: the adhesion tester, according to GB/T1720.2: salt water performance test by 3%NaCl solution, according to GB/T1763 test.(2) 2 primer will spray test plate process matching test.

(1) adhesion.

After coating plate corrosion resistance depends on the adhesion of coating adhesion size, bigger, stronger capability of sheet metal corrosion.Table 1 shows: film thickness, sandblasted samples than unmodified sandblasting thick; adhesion, sandblasted samples not less than without blasting processing model.

(2) of resistance to salt water.

Brine resistance refers to the model in salt, at the required temperature for immersion, observe the erosion degree.Salt water resistance is a measure of the film as well as material anticorrosion ability is an important index.Table 1: as can be seen by shot blasting and spraying paint, spraying precoating primer model than the uncoated precoating primer template anticorrosion ability; the same spray 2 primer, sandblasted model anti-corrosion ability than without blasting strong.

(3) process matching.

Paint process matching means two paint on together, between the layers is "at the end of the bite", shedding, blistering, wrinkling phenomenon.Don't appear these phenomena, that support good.Can be seen: whether sandblasting model or without blasting processing model, different paint magnet epoxy ester antirust paint with zinc phosphate polyurethane primer process matching good, no bubble, "at the end of the bite" phenomenon.This shows that: after sandblasting, sprayed magnet epoxy ester antirust paint as a pretreatment of steel, welding into the steel structure is then coated with a layer of zinc phosphate polyurethane primer.

5 conclusion through the test, and ultimately determine the steel structure new surface treatment and coating technology, namely by sandblasting and precoating primer combination of surface treatment process of steel: first is sandblasted, increasing the roughness, and then spraying the 1 magnet epoxy ester antirust paint as a precoating primer, to prevent steel after blasting corrosion of steel structure, welding after forming, the last 1 of zinc phosphate coating polyurethane primer.The process from the beginning of 1999, has been successfully applied to Sri Lanka EMUs and several other models, without any quality problems, indicates that the process is in full compliance with the design requirements and processes, to achieve the desired results.(end)

A steel structure new surface treatment and coating technology

1 Introduction
China s railway transportation several times greater speed, the railway locomotive vehicle design, production requirements are also getting higher and higher.The upgrading of products has become a pressing matter of the moment of the railway locomotive vehicle factory.Locomotive steel structure design increasingly used in high performance steel plate, the traditional steel structure surface treatment and coating technology has been unable to adapt to the requirements of production and development, the urgent need to find a meet design and technical requirements of the new surface treatment process.
2 surface treatment and coating technology of steel structure painting, in order to make the substrate and the coating has good adhesion, coating must be treated steel surface and the adjacent region of pretreatment.First of all, the surface must be clean, does not allow dust, oil, water or other dirt and loose oxide.Secondly, spraying, coating and substrate binding General mechanical combination, therefore, without affecting the coating quality under the premise, the coating and the substrate should be as much as possible to increase the contact area, the appropriate roughness is helpful to improve the adhesion of coating, coating service life extension.Related information: alkyd coatings used for manual surface rust coating, its service life is 2 ～ 3a, blasted to Sa2.5 level of service life for 10a.Pretreatment of steel surface directly affects the quality of coating engineering and apparent quality and the service life of the coating, and the surface treatment of the steel structure in cleanness and roughness directly affects the service life of coating.As much as possible to increase the contact area of the coating and the substrate, using mechanical roughening and sandblasting roughening method.Mechanical roughening includes shot peening, manual grinding and polishing processing.Sandblasting coarsening is the choice of diameter of 1 ~ 2mm dry and sharp sand and quartz sand, the sand from the use of compressed air blasting gun gun mouth high-speed jet to steel surface by sand, impact and friction, the steel surface oxide skin, rust, paint film, grease and other dirt removing, obtained at the same time having a certain roughness surface process.In general, the higher the grade of steel, surface treatment of the requirements of the higher.Sandblasted surfaces of steel structures, surface area is about not be sandblasted steel surface area 90 times, greatly increases the contact area between the substrate and the coating.This to some coatings, particularly inorganic zinc-rich coating coating adhesion effects greatly.
3 primary problems in the process of previously, locomotive and vehicle (including steel structure with steel plates and profiles) surface treatment method, one is just a simple scaling, the cold, heat processing, welding steel structure, the steel structure surface spraying primer.This process by a variety of models of the spot application, proof antiseptic effect.A second method is the surface of steel, after chemical treatment (usually phosphating treatment), directly after the primer spraying, and then welding steel structure.The drawback is often appear primer and phosphating film supporting not good question, resulting in reduced adhesion phenomena such as primer.Also, in recent years also uses a process, steel to be sandblasted, and then directly spraying anti-corrosion primer, also has the problem of poor, and even affect the next process.
4 new technology scheme according to the existing problems of the original process, to achieve process, design requirements, taking into account the process of inheritance and continuity, the theory as the basis, through the test, decided by sandblasting and precoating primer combination of surface treatment and coating process.