Mild steel pipes and is one of the low carbon steel pipes with low carbon content and the lesser hardness. Plus a small amount of pearlite microstructure of ferrite is characterized by low hardness (HB 100-130), low intensity (σb 372 ~ 470MPa) and high plasticity (δ 24 percent to 36 percent), and formability and good weldability.
The mechanical properties of mild steel pipe
Mild steel (hot rolled bars) has a apparent yield point, before clear signs of the destruction (large deformation, elongation) is a ductile failure.
Mechanical properties of hard steel pipe
Hard steel (heat treatment of steel and high strength steel wire) is with high strength, but poor plasticity, and brittleness. From the load to suddenly pull off, virtually non-existent yield phase (flow increase). Is a brittle failure.
Cold drawn and hot rolled bars are mild steel. Hard steel and mild steel is according to whether they exist division of the yield point, because hard steel has no significant yield point and plastic compared with mild steel, its control stress factor is lower than mild steel.