| 摘要 |
Provided is a steel sheet for soft-nitriding treatment which has a chemical composition consisting of, in mass%, C: more than or equal to 0.02% and less than 0.07%, Si: less than or equal to 0.10%, Mn: 1.1 to 1.8%, P: less than or equal to 0.05%, S: less than or equal to 0.01%, Al: 0.10 to 0.45%, N: less than or equal to 0.01%, Ti: 0.01 to 0.10%, Nb: 0 to 0.1%, Mo: 0 to 0.1%, V: 0 to 0.1%, Cr: 0 to 0.2%, and the balance: Fe and impurities, satisfies [Mn+Al‰¥1.5], and has a total content of Ti, Nb, Mo, V, and Cr present as precipitates in the steel sheet of less than 0.03% in mass%. The steel sheet for soft-nitriding treatment has a metal structure in which a ferrite area ratio is more than or equal to 80%, and a ferrite dislocation density at a position of 50 µm from a surface of the steel sheet is 1×10 14 to 1×10 16 m -2 . |
