高氮不锈轴承钢组织表征与滚动接触疲劳失效机制
Characterization of microstructure and mechanism of rolling contact fatigue of high nitrogen stainless bearing steel
李波 1史智越 2徐海峰 3胡忠会 1贾忠宁 1俞峰 3王存宇 3曹文全3
作者信息
- 1. 中国航空工业集团有限公司第一飞机设计研究院, 陕西 西安 710089
- 2. 中北大学材料科学与工程学院, 山西 太原 030051;钢铁研究总院有限公司特殊钢研究院, 北京 100081
- 3. 钢铁研究总院有限公司特殊钢研究院, 北京 100081
- 折叠
摘要
高氮不锈轴承钢作为第三代轴承钢材料,被广泛应用于航天飞机燃料泵轴承、飞机发动机主轴轴承等领域,现已经成为航空航天关键基础材料.而国内关于高氮不锈轴承钢滚动接触疲劳性能研究几乎空白,因此对加压电渣冶炼工艺制备的高氮不锈轴承钢采用不同回火温度热处理,进行力学性能测试、微观结构表征和滚动接触疲劳性能测试.结果表明,试验钢 1 030℃淬火+180℃回火热处理工艺抗拉强度为 1 899.7 MPa、硬度为60.7HRC,500℃回火后硬度与180℃相当,抗拉强度提升至2 213.5 MPa;通过对500℃高温回火试样基体表征,发现基体内纳米级Cr-N第二相析出是二次硬化现象产生的主要原因.180℃回火试样滚动接触疲劳寿命L10 为1.67×107,500℃回火试样L10为2.85×107,提高了70%;通过对2组试样疲劳剥落坑深入表征,发现180℃回火试样次表层沿晶断裂是引起滚动接触疲劳失效的主要原因;结合基体残余应力测量结果分析,500℃高温回火残余拉应力为41 MPa,低于180℃回火的101 MPa.高温回火基体内析出的纳米级Cr-N第二相可以降低位错的运动能力,同时减弱了基体内部应力集中,使得滚道次表层沿晶断裂倾向减小,滚动接触疲劳寿命显著提高.对高氮不锈轴承钢不同回火工艺微观组织结构、滚动接触疲劳性能、裂纹萌生机制进行了深入研究分析,为高氮不锈轴承钢热处理工艺制定、抗疲劳机制研究以及材料研发应用提供试验与理论基础.
Abstract
High nitrogen stainless bearing steel(HNSBS),as a third-generation bearing steel material,is widely used in fields such as fuel pump bearings for aerospace shuttles and aircraft engine spindle bearings.It has become a key basic material for aerospace.However,there is almost no research on the rolling contact fatigue(RCF)performance of HNSBS in China.Therefore,different tempering temperatures for heat treatment of HNSBS prepared by pressur-ized electroslag smelting process were used,and conducts mechanical properties testing,microstructure characteriza-tion,and RCF testing.The results show that the tensile strength of the test steel quenched at 1 030℃ and tempered at 180℃ is 1 899.7 MPa,with a hardness of 60.7HRC.After tempering at 500℃,the hardness is equivalent to 180℃,and the tensile strength is increased to 2 213.5 MPa.By characterizing the matrix of the 500℃ tempered sample,it was found that the nanoscale Cr-N precipitation in the matrix is the main reason for the occurrence of sec-ondary hardening phenomenon.The RCF life L10 of the 180℃ tempered sample is 1.67×107,while the L10 of the 500℃ tempered sample is 2.85×107,which is 70%higher than that of the 180℃ tempered sample.Through in-depth characterization of fatigue spalling in the matrix of two specimens,it was found that intergranular fracture in the subsurface layer of the 180℃ tempered specimen is the main cause of RCF crack initiation.Based on the analysis of the results of residual stress in the matrix,the residual tensile stress after high-temperature tempering at 500℃ is 41 MPa,which is lower than 101 MPa after tempering at 180℃.The nanoscale Cr-N precipitated in the high-temperature tempered specimen can reduce the mobility of dislocations and weaken the stress concentration inside the matrix,resulting in a decrease in the tendency of intergranular fracture in the subsurface layer of the raceway and significantly improves the RCF life.Through in-depth research and analysis on the microstructure,RCF,and crack initiation mechanism of HNSBS under different tempering processes,providing experimental and theoretical basis for the for-mulation of heat treatment processes,research on fatigue resistance mechanisms,and material development and appli-cation of HNSBS.
关键词
高氮不锈轴承钢/微观结构/滚动接触疲劳/疲劳剥落/疲劳裂纹萌生Key words
high nitrogen stainless bearing steel/microstructure/rolling contact fatigue/fatigue spalling/fatigue crack initiation引用本文复制引用
基金项目
国家重点研发计划(2016YFB0300101)
出版年
2024
NETL
NSTL
万方数据