| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a method of producing cold-rolled steel sheets, less in deterioration of yield and productivity when performing quality control for surface defects resulted from nonmetallic inclusions in steel. <P>SOLUTION: The method of producing the cold-rolled steel sheets includes: obtaining beforehand relationship among the size of a nonmetallic inclusion existing in a slab, which is detected by a defect detection device, the depth-directional position of the same from a slab surface and expectation as to whether or not the nonmetal inclusion causes a surface defect when the slab is formed into a cold-rolled steel sheet; and performing the quality control based on the detection result of the nonmetal inclusion in the slab by the defect detection device, wherein the size of the nonmetal inclusion represents the maximum length of the nonmetal inclusion in a slab width direction and the depth-directional position of the nonmetal inclusion from the slab surface represents the shortest distance between the slab surface and the surface of the nonmetal inclusion. <P>COPYRIGHT: (C)2012,JPO&INPIT |
