| 摘要 |
PROBLEM TO BE SOLVED: To provide a method of manufacturing a cold rolled steel sheet capable of stably manufacturing a good quality cold rolled steel sheet.SOLUTION: A method of manufacturing a cold rolled steel sheet having a component composition containing C of 0.05 mass% to 0.3 mass%, Si of 0.6 mass% to 3.0 mass%, Mn of 1.0 mass% to 3.0 mass%, P of 0.1 mass% or less, S of 0.01 mass% or less, Al of 0.01 mass% to 1.0 mass%, N of 0.01 mass% or less, and the balance Fe with inevitable impurities and manufactured through a reduction annealing treatment after an oxidation treatment includes a measurement step of measuring the amount of iron-based oxides formed on a surface of the steel sheet after the oxidation treatment by each form of the iron-based oxides, a step of determining conditions of the annealing treatment on the basis of an evaluation index calculated from the amount of iron-based oxides by form measured in the measurement step, and a step of conducting the annealing treatment according to the determined conditions. |
