Patent ID: 7727342
Filing Date: 2010-06-01
Classification: C22C

Abstract:
1. A low carbon microalloyed steel tube or bar, in a hot rolled and air cooled condition having a microstructure consisting precipitation strengthened ferrite and pearlite, said steel consisting essentially of in weight %: 0.06-0.30 C; 0.5-1.5 Mn; 0.04 max S; 0.025 max P; 1.0 max Si; >1.0-2.0 Ni; 0.05-0.30 V; 0.01-2.0 Cu; 0.0010-0.0250 N; up to 0.2 Cb; 0.05-0.3 Cr; up to 0.15 Mo; 0.01-0.03 Al; balance Fe and minor additions and impurities, and wherein said steel has a carbon equivalent value, C.E., ranging between 0.3-0.55, calculated by the formula: