Steel Structure Operation Process (2)

C. Straightening and forming

a.Straightening
b.Cold straightening of finished products, generally using mechanical forces such as flange levelers, bracing machines, hydraulic presses, presses, etc. for straightening.
c. Flame straightening, heating methods such as point heating, linear heating and triangular heating.

Low carbon steel and ordinary low-alloy steel heat correction heating temperature is generally 600 ~ 900 ℃, and 800 ~ 900 ℃ for the ideal temperature of thermoplastic deformation, but is not allowed to exceed 900 ℃.
Medium carbon steel will produce cracks due to deformation, so medium carbon steel is generally not flame correction.
Ordinary low-alloy steel should be slowly cooled after heating correction.

Forming

Thermal processing: For low carbon steel is generally in 1000 ~ 1100 ℃, thermal processing termination temperature should not be less than 700 ℃. The heating temperature at 500 ~ 550 ℃. Steel produces brittleness, hammering and bending are strictly prohibited, otherwise, the steel will easily fracture.
Cold working: steel is processed and made at room temperature, most of which is carried out using mechanical equipment and special tools.

D. Edge processing (including end milling flat)

a. Commonly used edge processing methods mainly include shovel edge, planing edge, milling edge, carbon arc gas planing, gas cutting and beveling machine processing.
b. Gas-cut parts, when the need to eliminate the impact area for edge processing, the minimum machining allowance of 2.0mm.
c. The depth of the machined edge should ensure that the surface defects are removed, but not less than 2.0mm, there should be no damage and cracks on the surface after processing, and the grinding marks should follow the edge when grinding wheel processing is carried out.
d. The edges of the parts of carbon structural steel should be cleaned up on the surface after manual cutting, and there should be no unevenness of more than 1.0mm
e. The end support edge of the component requires planing and top tightening and the component end section with high accuracy, no matter what method of cutting and what kind of steel it is made of, the edge should be planed or milled.
f. Construction drawings that have special requirements or provisions for welding edges need to plan the edge, the general shear edge of the plate or section does not need to plan.
g. Parts edge for the mechanical automatic cutting and air arc cutting after the flatness of its cutting surface, are not more than 1.0mm. the free edge of the main stress members, after air cutting requires planing or milling edge machining allowance, at least 2mm per side, should be free of burrs and other defects.
h. The top tight contact surface of the column end after milling should be more than 75% of the area tightly, checked with 0.3mm plugging rule, the plugging area should not be more than 25%, and the edge gap should not be more than 0.5mm.
i. The choice of milling port and milling volume should be decided according to the workpiece material and processing requirements, and a reasonable choice is the guarantee of processing quality.
j. The end processing of the component should be carried out after the correction is qualified.
k. Necessary measures should be taken according to the form of the component to ensure that the milling flat end is perpendicular to the axis.