METHOD FOR PRODUCING A STEEL TUBE AND A HIGHLY FORMABLE AND HIGH STRENGTH MULTIPHASE STEEL TUBE

摘要

The invention relates to a method for producing a steel tube and to a steel tube containing Fe, unavoidable impurities and residual contents and containing additionally in mass 0.05 to 0.25 % of C, 2.0 % or less of Si, 0.25 to 2.5 % of Mn, 2.5 % or less of Al 2.0 % or less of Cr, 1.0 % or less of Mo, 0.3 % or less of Ti+Nb+V, and having a manganese equivalent of 1.3 to 3.9 as defined by the following formula (1) Mneq = Mn + 124B(%) +3Mo(%) + 1Cr(%) + ?Si(%) + ?Ni(%) + Cu(%) (1).