how to stress relieve astm a572?

The ASTM A572 specification is the Standard Specification for High-Strength Low-Alloy Columbium-Vanadium Structural Steel for plates used in general construction and structural applications. 
For ASTM A572 welded steel pipe, it is necessary to carry out the necessary preheating and post-heat treatment of welded steel pipe to eliminate the stress in the weld zone and improve the performance of welded steel pipe.
Seamless steel pipe is generally shipped from the factory with stress relieving treatment, but of course, if you want to make sure that nothing is wrong, you can also carry out heat treatment and preheating treatment for stress relieving treatment.
Yuantai Derun usually uses heating furnace and four-corner heating equipment to carry out stress relieving treatment of steel pipes.
A572 steel is typically used in structural applications due to its high strength, ductility, weldability and corrosion resistance.These applications include structural sections, reinforcing bars, bridges, skyscrapers and houses.