摘要
通过滚动接触疲劳试验,测试了进口与国产两种5%Cr支承辊用钢的P-S-N疲劳曲线与疲劳强度,分析了试样接触疲劳层的显微硬度与组织特征,探讨了大型锻钢支承辊的接触疲劳机制。结果表明,(1)进口支承辊钢的疲劳强度为1 249 MPa,国产支承辊钢的疲劳强度为1 070 MPa,进口支承辊由于晶粒细小具有更高的抗接触疲劳能力;(2)在交变接触应力的作用下,支承辊疲劳层呈现局部硬度升高、马氏体和贝氏体破碎等一系列性能与组织结构变化;(3)随着循环使用及修磨次数的增加,支承辊接触疲劳最大损伤位置向表面移动,累积损伤值逐渐增大,最终二者均趋于某一恒定值。
P-S-N fatigue curves and fatigue strengths of imported and domestic 5% Cr steels for large-sized forged backup rolls were tested through the rolling contact fatigue test. The microhardness and microstructure characteristics within the fatigue layer of the samples were analyzed. The contact fatigue mechanism of large-sized forged backup roll was discussed. The results showed that the fatigue strength of the imported backup roll steel was 1 249 MPa,while the domestic one was1 070 MPa,the imported one had higher contact-fatigue-resistance due to its fine grains; A series of microstructure and performance changes were occurred in the backup roll fatigue layer under the action of alternating contact stresses,for example,the local hardness increased,martensite and bainite crashed and fractured,etc.; The maximum contact fatigue damage location of the backup roll was moved to the surface,and the accumulative damage value was gradually increased with the number of cyclic utilization and grinding,both all tended to be stable at last.
作者
温宏权
姚利松
Wen Hongquan Yao Lisong(Baoshan Iron ＆ Steel Co. , Ltd. , Research Institute, Shanghai 201900, China)
出处
《上海金属》
CAS
北大核心
2018年第3期18-22,共5页
Shanghai Metals
关键词
接触疲劳
显微组织
疲劳损伤
支承辊
contact fatigue
microstructure
fatigue damage
backup roll
