高强韧性奥氏体-贝氏体双相钢接触疲劳特性

The Rolling Contact Fatique Behaviours of Austenite-Bainitic Dual-Phase Steels with High Strength and Good Toughness

考察了新型高强韧性奥氏体-贝氏体组织的低合金超高强度钢(简称奥-贝钢)的接触疲劳性能,并与20CrMnTi钢碳、氮共渗淬火回火组织进行对比研究;探讨了钢的组织结构及力学性能与接触疲劳性能的关系,提出了获得高接触疲劳性能要求的组织、性能合理匹配。研究结果表明,奥-贝钢280℃等温形成的硬度只有HRC50～52的奥-贝组织接触疲劳寿命是硬度HRC58～62的回火马氏体组织和20CrMnTi钢碳氮共渗淬火回火组织的2～4倍,奥-贝钢具有优异的抗接触疲劳性能。

The rolling contact fatigue behaviours of the newly developed low alloy-extra high strength austenite-bainitic ferrite dual-phase steels (called A-B steel), which has a excellent combination of high yield strength and high toughness, are researched, and compared with that of carbonizingnitriding microstructure for 20CrMnTi and SCM420H steels. Further investigation is made on relation between microstructure, mechanical property and contact fatigue life. It is shown that contact fatigue life of austenite-bainitic microstructure with hardness HRC50～52 is 2～4 times of tempered martensite and carbonizing-nitriding microstructure for 20CrMnTi and SCM420H steels with hardness HRC58～62, and that A-B steel has very outstanding resistance to contact fatigue. It is concluded that only those materials (microstructure) which have very excellent combination of high yield strength and high toughness are the most ideal condidates to resist rolling contact fatigue.