车轮轧制用斜辊径向通裂失效分析  

Failure Analysis of Radial Overall Crack of Oblique Roller in Wheel Rolling

作　　者：侯沛云 杜晓钟[2] HOU Pei-yun;DU Xiao-zhong(Taiyuan Heavy Industry Rail Transit Equipment Co.LTD,Taiyuan 030032,China;School of Mechanical Engineering,Taiyuan University of Science and Technology,Taiyuan 030024,China)

机构地区：[1]太原重工轨道交通设备有限公司,太原030032 [2]太原科技大学机械工程学院,太原030024

出　　处：《太原科技大学学报》2022年第1期29-33,共5页Journal of Taiyuan University of Science and Technology

基　　金：山西省重点研发计划(201703D111005)。

摘　　要：针对斜辊服役过程中发生的提前失效,分别对其化学成分、低倍组织、材质纯净度、断面硬度、微观组织、扫描电镜断口等项目进行了系列的试验与分析。试验结果表明,斜辊所用材料化学成分符合标准要求,非金属夹杂物级别较低,锻造致密度、均匀性良好;但基体硬度高于技术要求,微观组织粗大,属严重过热组织形态。分析认为,斜辊径向裂纹属外表面接触疲劳开裂+内表面花键齿根角部应力集中型高频弯曲疲劳开裂汇合形成的径向通体开裂与掉块。斜辊开裂产生的主要原因为热处理工艺或操作不当产生严重过热组织,硬度过高,材料脆性大大增加,耐热疲劳能力下降,最终导致斜辊疲劳开裂并扩展至断裂。In view of the premature failure during the service of the oblique roller, a series of tests and analyses were carried out, such as chemical composition, macrostructure, material purity, the section hardness, microstructure, scanning electron microscope fracture.The test results show that the chemical composition of the material used in the oblique roller meets the standard requirements, the level of non-metallic inclusion is better, and the forging density and uniformity are good.However, the matrix hardness is higher than the technical requirements, and the microstructure is coarse and belongs to the seriously overheated microstructure.According to the analysis, the radial crack of the oblique roller is formed by the combination of external surface contact fatigue crack and internal surface spline root corner stress concentrated high frequency bending fatigue crack.The main reasons of the oblique roller cracking are that the improper heat treatment process or operation leads to the serious overheating microstructure, the hardness is too high, the material brittleness is greatly increased, and the resistance ability of heat fatigue decreases, which eventually leads to the oblique roller fatigue cracking and extends to the fracture.

关 键 词：斜辊 通裂 硬度 过热组织 应力集中 

分 类 号：TG142[一般工业技术—材料科学与工程]