| abstract |
A steel sheet for nitriding treatment excellent in moldability and punching property is provided. P: not more than 0.05%, S: not more than 0.02%, Al: not less than 0.01% and not more than 0.06%, Cr: not more than 0.08%, Si: not more than 0.1% : Not less than 0.5% and not more than 1.5%, N: not more than 0.01%, and the balance of Fe and inevitable impurities, and a composition comprising ferrite as a main phase and pearlite and / or bainite as a second phase And the ferrite has an average grain diameter of not less than 5 탆 and not more than 25 탆 in a cross section of the cementite in the rolling direction of the steel sheet, And a structure having an average length of major axis of 3.0 탆 or less. |