You can have cold formed and hot rolled steel with equal yield stresses.
There are the following differences:
If you have to care for stability, cold formed steel does not perform as well as hot rolled steel, because it is prestrained by the cold forming process.
If you want to weld the cold formed steel, you have to care for the following two points (not for welding the hot rolled steel):
If you have a QHP or a RHP (cold formed), for example, you have to be cautious with welding at the corner part (cold formed part) of the profile. In
Some steels get there yield stresses, they have, with cold forming. The steel itself has lower yield stresses and is hardened by cold forming. If you weld this steel, it looses the prestraines and therefore its higher yield stresses. The yield stresses may fall to the lower yield stresses, it has without cold forming.
So the properties of hot rolled steel are usually better than the properties of cold formed steel with equal given yield stresses.
Regards
Al
Alfred Mueller
International welding engineer
University of applied sciences,
Von: Lakshmana Nukala [mailto:lakshmana.nukala@gmail.com]
Gesendet: Samstag, 27. Oktober 2007 07:22
An:
Betreff: Hot Rolled Vs Cold formed steel properties
Hi all
Can any one help on the difference between the hot rolled and cold formed steel properties?
Does cold formed steels have higher yeild stresses than hot rolled?
Best Regards
Lakshmana RK Nukala