| 摘要 |
PROBLEM TO BE SOLVED: To provide a high tensile strength steel sheet which has satisfactory toughness, has excellent strength and toughness, in particular, toughness in a direction orthogonal to a rolling direction, and has a satisfactory balance in the characteristics and cost effectiveness. SOLUTION: The high tensile strength steel sheet for welding has a composition containing, by mass, 0.02 to 0.10% C, 0.05 to 0.65% Si, 0.40 to 2.00% Mn, <=0.003% S, 0.50 to 2.00% Cu, and <=0.005% Si, and, the pole density of each direction in a reversed pole figure to the direction of the normal of the sheet face is <=3.2. In the method of producing the high tensile strength steel sheet for welding, a steel slab of a rolling stock is subjected to rolling in a width direction at <=1,250 deg.C so as to control the draft in the process of the rolling to >=30%, and is hot-rolled at a finishing temperature of an Ar3 point-30 deg.C or higher, so that the pole density of each direction in a reversed pole figure to the direction of the normal of the sheet face is controlled to <=3.2.
|
