METHOD OF PRODUCING COLD ROLLED STEEL SHEET

摘要

PROBLEM TO BE SOLVED: To provide a method of producing a cold rolled steel sheet enabling stable production of a cold rolled steel sheet of good quality.SOLUTION: A method of producing a cold rolled steel sheet includes at least an annealing treatment and an acid cleaning treatment and comprises a measurement step of measuring amounts of iron-based oxides formed on the surface of a cold rolled steel sheet by the form of iron-based oxides by using an X-ray diffraction method, a determination step of determining treatment conditions for one or both of the annealing treatment and the acid cleaning treatment on the basis of evaluation indices calculated from the amounts of iron-based oxides by the form of iron-based oxides measured in the measurement step and a step of carrying out the annealing treatment and the acid cleaning treatment according to the treatment conditions determined.