| 摘要 |
PURPOSE:To obtain a steel having superior resistance to hydrogen induced cracking and enduring well a severe corrosive environment by adding prescribed percentages of C, Si, Mn, Al, Ca, P and S and carrying out rolling at a prescribed temp. CONSTITUTION:A steel contg. <=0.04% C, 0.01-0.5% Si, 0.8-2% Mn, 0.01- 0.1% Al, 0.0005-0.005% Ca, <=0.015% P and <=0.002% S is cast. The steel may further contain one or more among 0.05-0.5% Cu, 0.05-0.5% Ni, 0.05-0.5% Cr, 0.05-0.5% Mo, 0.01-0.1% Nb, 0.01-0.1% V, 0.005-0.05% Ti and 0.0005- 0.008% B. The cast steel is hot rolled at >=50% draft at <=950 deg.C, and it is cooled from the pearlite forming temp. or above to <=600 deg.C at 3-15 deg.C/sec cooling rate. The rolling finish temp. is regulated to the Ar3 transformation point + or -50 deg.C. |
