STEEL STRIP FOR ELECTRIC-RESISTANCE-WELDED STEEL PIPE OR TUBE ELECTRIC-RESISTANCE-WELDED STEEL PIPE OR TUBE AND PROCESS FOR PRODUCING STEEL STRIP FOR ELECTRIC-RESISTANCE-WELDED STEEL PIPE OR TUBE

摘要

A strength of X70 or higher, and a very high resistance to HIC and SSC resistance. P: 0.01% or less, S: 0.001% or less, V: 0.04% to 0.07%, Nb: 0.04% to 0.07% 0.01 to 0.04% of Ti, 0.1 to 0.3% of Cu, 0.1 to 0.3% of Ni, 0.001 to 0.005% of Ca, 0.01 to 0.07% of Al and 0.007% or less of N and the balance Fe and inevitable impurities And the content of C, Nb, V and Ti satisfies the following formula (1), and the ferrite area ratio is 90% or more. [C]-12 ([Nb] /92.9 + [V] /50.9 + [Ti] /47.9) 0.03% . (One)