1) steel mechanics indicators: structural steel, mechanical indicators including the yield point, tensile strength, elongation, low temperature impact toughness. These indicators should be consistent with the requirements of the design of steel structures, low temperature impact toughness only in the structure may be at work when you want to test a low-temperature environment. The steel mechanical indicators Determination steel mechanical and process performance test sampling requirements "(GB2975-82) subject to (2) Steel Chemical composition: and steel workability, toughness, durability, etc.. Which is the carbon content of the limit of the content of alloying elements and impurity elements such as sulfur, phosphorus content should comply with the specification (GB222-84) requirements. (3) process performance: process performance the weldability and processing performance. Weldability carbon content or carbon equivalent (low alloy steel), available weldability test identification. Processing performance by the cold bend test to determine. (GB232-88) as the 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 allowable range. Allowable deviation value can refer to the national standard GB709-88, GB706-88, GB787-88, GB978-88, GB707-88, GB816-87. (5) steel shape defects: the steel surface shall bubbles, scarring, crack, cracks, folds, inclusions and pressed into the oxide scale. These deficiencies must be cleared, cleared Department depression depth shall not be greater than the thickness of the steel negative deviation. Further, when the steel material surface corrosion, pitting or scratches and other defects, the depth should be such as not greater than 1/2 of the negative deviation 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 the 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 forming machining: means that the steel is heated to a certain temperature and then processed. This method is suitable for forming, bending, and correction can not be done at room temperature of the workpiece. Thermal processing termination shall not be less than 700 ° C temperature. Heating temperature of the steel at 200 ~ 300 ℃ 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. Beyond material yield strength of the material will produce the required permanent deformation due to an external force, or due to an external force beyond the certain portion of the ultimate strength of the material for the material requirements and material from the press. Cold working has the material hardens the trend becomes brittle, and thus through the heat treatment of the steel to restore the normal state or planing cut off to harden more serious edge portion. The ambient temperature is below -16 ℃ not the cold working of carbon steel. Processing of low-alloy steel, not less than -12 ℃. (11) bending: according to the design requirements, processing equipment and tooling plate or made of section steel bending process certain shape. Cold-formed suitable for sheet metal, small steel; bending suitable for thicker plates and more complex components, steel, bending temperature of 950 to 1100 ° C. (12) Coil processing: the elongation of the outer fiber of the flat steel plate, the inner fiber shortening in the external force generated by bending deformation of the method. The coil was completed by coiling machine. Depending on the material temperature, divided into cold rolled and hot rolled. The coil is mainly used for welding round column, piping, air bag. (13) Flap: bend the edge of the steel components into a certain point of view or a certain shape process called folding. The hemming general for sheet metal components. Hem hem machine commonly used with the appropriate mold. (14) molding: molding pressure equipment using the mold method of forming a steel. Specific approach had its ups and downs metal forming, punching forming, bending, rolling, stretching, rolling, etc.. (15) shovel edge: shovel edges shovel head hammering eradicate the excess part of the edge of the metal to form a groove. Shovel edge manual and pneumatic wind utilized wind shovel. The shovel section of lower accuracy, generally used for less demanding, a small amount of machining of the groove. (16) planing: planing the workpiece is pressed to the edge of the planer along the processing reciprocating dig the groove. Planing planing straight edge or a hypotenuse. (17) Milling: Milling and planing similar and just planing machine instead of walking the griffe the turret and planer disc cutter, cutter along the edge in a straight line at the same time for rotation, processing ergonomics higher. (18) carbon arc gouging for: the carbon rod arcing between the electrodes, and planing metal heating the metal to melt, and then blow off with compressed air to melt metal. The Ergonomics higher. (19) sampling method: put the components in the assembly platform at a 1:1 real kind, and then based on the location of the parts on the real kind, are assembled into components. (20) imitation type replication method: the first sample method of the land to be assembled into a single-sided structure, plus the tack welding, and then turn over the membranes as a copy, in the above assembly of another single-sided structure. Apply to cross-sectional mutually symmetrical truss structure (21) Li loading: stable position depending on the characteristics of its parts in member, to select the top-down or bottom-up assembly, adapted to be placed stationary, the height is not a structure. (22) lying Packing: member placed supine position assembly. For sectional little but the length of the elongated member. (23) membranes assembly method: the component parts with membranes positioning assembled in the assembly position. Used in the manufacture of components of large quantities of high precision products. (24) The electric arc welding: the use of the heat of the arc generated between the electrodes and the workpiece metal alloying process known as electric arc welding. Manual welding arc welding, automatic welding, semi-automatic welding and gas-shielded welding points. (25) resistance welding: the current through the two contact weldment, by generating a high temperature in the resistance of the contact at maximum, current, so that material is in a semi-molten state, at the applied pressure and fused together. Generally used for butt round bar or spot welding steel plate. Electroslag welding of (26): by resistance heat generated by the current through the slag to the molten metal to be welded. As for the box-shaped columns and beams rigidly connected column connected to the beam at the upper and lower flange stiffeners melt through welding. Manual welding of (27): All with manual arc welding, low efficiency, quality on their own, poor stability, but flexible, suitable for shorter rather complex the weld or site welding. (28) automatic submerged arc welding: arc welding buried beneath the powdered flux by mechanical automatic sprinkle flux and send mobile welding wire. Applied to a longer weld. Weld quality and high efficiency. (29) gas shielded arc welding: CO2 or argon shielded arc welding molten metal, wire and gas sent are automatically, only manually move the welding torch. The case of semi-automatic welding, the welding quality and high efficiency. (30) shot blasting: shot blasting particle size of 0.8 ~ 2.0mm steel shot projectile machine impeller center inhalation directional high-speed impeller tip thrown, fired need for anti-rust steel surfaces to mechanical descaling The purpose of this method is rust efficiency, low costs, less pollution.