What is cold drawing and cold rolling
Cold drawing and cold rolling is common in iron and Steel production process, production of Seamless Tube will need to use to the cold drawing cold rolling process, to make Stainless Steel TP304 Seamless Tube, Stainless Steel TP304L Seamless Tube, etc. So how do these two processes understand, what specific differences, we will through the following brief understanding.
Cold drawing refers to the forced drawing of round bar through the hole of hard alloy wire drawing die. The cold drawing effect is stronger than the pure drawing action. The reinforcement is not only pulled but also squeezed. After one or more cold drawing, the yield point of low carbon steel wire can be increased by 40%~60%, but it loses the plasticity and toughness of mild steel and has the characteristics of hard steel.
Cold rolling is a round bar that is rolled into regular sections on a cold rolling mill to improve its strength and adhesion to concrete. When the steel bar is rolled in cold rolling, it deforms both lengthwise and crosswalk at the same time, so its plasticity and internal structure uniformity can be well maintained.
Cold rolling and cold drawing both belong to plastic deformation, and the reinforcement will not rebound after deformation, forming and fixing. The deformation mode of cold rolling has some advantages, and the surface roughness and dimension accuracy are relatively high. However, cold rolling also has certain limitations, not all sizes can be processed, the size of the finished product of cold rolling needs to be adjusted by the roll gap to achieve, some finished product size after several passes of rolling, can not get the ideal size of the finished product, but also need to use cold drawing to achieve.
In terms of mechanical properties, cold rolling can not only improve the tensile strength, but also the compressive strength. Cold drawing only increases tensile strength. These two processing methods, by changing the steel deformation, to improve the strength and hardness of the effect. However, the yield strength ratio of the treated steel increases and the safety reserve decreases and the ductility decreases.
In short, the cold drawing deformation is small and the speed is fast. Cold rolling, through the mill, large deformation, slow speed, but the relative process is better.