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
http://steelpergolas.blogspot.com/2012/12/on-fire-resistant-design-method-based.html
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