Patent ID: 9062364
Filing Date: 2015-06-23
Classification: C21D,C22C,C23C

Abstract:
1. A method for producing a carbonitrided member comprising the steps of: carburizing a steel part having a composition of, by mass percent, C: 0.10 to 0.35%, Si: 0.15 to 1.0%, Mn: 0.30 to 1.0%, Cr: 0.40 to 2.0%, S: 0.05% or less with the balance being Fe and impurities in a carburizing atmosphere at a temperature of 900 to 950° C.; then, while maintaining the carburizing atmosphere, carbonitriding the steel part immediately following the carburizing by holding the carburized steel part in a temperature of 800 -900C. in a carbonitriding atmosphere having a nitrogen potential of 0.2 to 0.6%; quenching the carbonitrided steel part; and shot peening the quenched steel part while heating to a temperature not higher than 350° C. or immediately after heating to a temperature not higher than 350° C., wherein the carburizing atmosphere is maintained with a constant carbon potential throughout carburizing and carbonitriding and up to quenching.