STEEL FOR NITROCARBURIZING AND NITROCARBURIZED COMPONENT, AND METHODS OF PRODUCING SAME

• Main Authors: TOMITA, Kunikazu, KASAI, Masayuki, IWAMOTO, Takashi
• Format: Patent
• Language: English; French; German
• Published: 31.01.2018
• Subjects: ALLOYS; CHEMISTRY; FERROUS OR NON-FERROUS ALLOYS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUSMETALS OR ALLOYS; MAKING METAL MALLEABLE BY DECARBURISATION, TEMPERING OR OTHERTREATMENTS; METALLURGY; METALLURGY OF IRON; MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; TREATMENT OF ALLOYS OR NON-FERROUS METALS

Disclosed is a steel for nitrocarburizing whose mechanical workability before nitrocarburizing treatment is guaranteed by ensuring fatigue resistance without causing the steel to harden before subjection to nitrocarburizing treatment, and a method of producing the same. The steel for nitrocarburizing has a chemical composition that contains C: 0.01 % or more and less than 0.20 %, Si: 1.0 % or less, Mn: 1.5 % or more and 3.0 % or less, P: 0.02 % or less, S: 0.06 % or less, Cr: 0.30 % or more and 3.0 % or less, Mo: 0.005 % or more and 0.40 % or less, V: 0.02 % or more and 0.5 % or less, Nb: 0.003 % or more and 0.20 % or less, Al: 0.010 % or more and 2.0 % or less, Ti: more than 0.005% and less than 0.025 %, N: 0.0200 % or less, Sb: 0.0005 % or more and 0.02 % or less, and the balance consisting of Fe and incidental impurities, with the chemical composition satisfying a predetermined relation; and a steel microstructure that contains bainite phase in an area ratio of more than 50 %.