CARBURIZED MEMBER

• Main Authors: ICHINOMIYA KATSUYUKI, FUKUOKA KAZUAKI
• Format: Patent
• Language: English; Japanese
• Published: 08.10.2020
• Subjects: ALLOYS; CHEMISTRY; FERROUS OR NON-FERROUS ALLOYS; METALLURGY; TREATMENT OF ALLOYS OR NON-FERROUS METALS

To provide carburized members such as gears and shafts having excellent torsional fatigue resistance in addition to excellent impact fatigue resistance.SOLUTION: The carburized member comprises in terms of mass%: C: 0.16% or more and 0.35% or less, Si: 0.01% or more and 0.20% or less, Mn: 0.50% or more and 1.5% or less, P: 0.015% or less, S: 0.03% or less, Cu: 0.30% or less (including 0%), Cr: less than 2.0%, Mo: 0.16% or more and 0.70% or less, Al: 0.055% or more and 0.100% or less, B: 0.0004% or more and 0.0030% or less, and N: less than 0.0070% in a range in which the I value according to the following formula (1) is 0.028 or more, as well as the balance comprising Fe and unavoidable impurities, and a carburized layer. I=14/27×Al+14/10.8×B-N (1), where Al, B, and N in the formula (1) are the content (%) of each element.SELECTED DRAWING: None 【課題】優れた耐衝撃疲労特性に加えて優れた耐ねじり疲労特性を有する歯車やシャフトなどの浸炭部材を提供する。【解決手段】Ｃ：0.16質量％以上0.35質量％以下、Si：0.01質量％以上0.20質量％以下、Mn：0.50質量％以上1.5質量％以下、Ｐ：0.015質量％以下、Ｓ：0.03質量％以下、Cu：0.30質量％以下（０質量％を含む）、Cr：2.0質量％未満、Mo：0.16質量％以上0.70質量％以下、Al：0.055質量％以上0.100質量％以下、Ｂ：0.0004質量％以上0.0030質量％以下およびＮ：0.0070質量％未満を、次式（１）に従うＩ値が0.028以上となる範囲にて含有し、残部はFe及び不可避不純物の成分組成と、浸炭層とを有する浸炭部材とする。Ｉ＝14/27×Al＋14／10.8×Ｂ−Ｎ・・・・（１）但し、上式（１）におけるAl、ＢおよびＮは各元素の含有量（質量％）【選択図】なし