| 摘要 |
Temper rolling at a total elongation percentage of 0.1% or more is performed on a steel strip using a temper rolling mill in which at least one roll stand having high roughness work rolls, the center-line averaged roughness Ra of which being in the range of 3.0 to 10.0 µm, is provided, or at least one roll stand having bright rolls is further provided downstream of the above roll stand, and as a result, a predetermined elongation percentage, flatness, and center-line averaged roughness can be imparted even to a steel strip having a yield strength of 340 MPa or more at a rolling load approximately equivalent to that for a mild steel without using a large facility and complicated control. In particular, a high tensile-strength cold rolled steel sheet having an Ra of 0.5 to 3.0 µm and superior die galling resistance is obtained. |
