COLD ROLLED STEEL SHEETS HAVING AN IMPROVED PRESS FORMABILITY

摘要

A cold rolled steel sheet or plated steel sheet having an improved press formability as well as excellent phosphatability, resistance to galling and spot weldability is produced by controlling a surface roughness pattern of the steel sheet so as to satisfy a center-line average surface roughness of 0.3-2.0 mu m and a regularity parameter in at least one direction of not more than 0.25 defining the regularity of surface roughness.