摘要
高速齿轮轴在经过渗碳和淬、回火热处理后的喷丸过程中,其齿部表面出现多处凹坑。利用光学显微镜、扫描电子显微镜、直读光谱仪和显微硬度计等对齿部表面的凹坑进行了失效分析。结果表明:齿部制面的凹坑区域存在沿晶扩展的微裂纹,另还存在沿晶界分布的碳化物;表面出现凹坑是由于在渗碳后的空冷过程中表面产生了"⊥"型裂纹,在随后的停放期间和等温淬火时"⊥"型裂纹沿轴向或径向进一步扩展形成剥离裂纹,继而于喷丸过程中表层断裂脱落,产生凹坑。
Many pits were found on the tooth surface of high-speed gear shaft in the blasting shot treatment process after the gear shaft was carburized, quenched and tempered. Optical microscope, scanning electronic microscope, direct-reading spectrograph and microhardness tester were employed to analyze the pits. The results show that intercrystalline-extended micro cracks existed on the pit zone of the tooth surface, and there was intercrystalline-distributed carbide at the same time. “⊥”type cracks were generated on the surface after carburized in the process of air cooling. “⊥” type cracks expanded longitudinally to form decotlement crack during the subsequent storage period and isothermal quenching, broke and sloughed in the process of blasting shot, then the pits appeared.
出处
《理化检验(物理分册)》
CAS
2009年第12期758-760,764,共4页
Physical Testing and Chemical Analysis(Part A:Physical Testing)
关键词
渗碳
凹坑
剥离裂纹
喷丸
齿轮轴
carburized
pit
decollement crack
blasting shot
gear shaft