摘要
为了查明某批锥齿轮出现裂纹的原因,利用扫描电镜、直读光谱仪和金相显微镜分析了锥齿轮的断口形貌、化学成分和微观组织。结果表明:锥齿轮齿部的化学成分和显微组织符合技术要求。裂纹源在次表层位置,该位置有O、Al、Ca、Mg等元素形成的氧化夹渣物,且锥齿轮心部具有较为严重的带状偏析,恶化了材料的力学性能。裂纹源所在的次表层可能先于表层发生马氏体转变,并且处于变径界面上,具有较大的应力集中,从而导致了其纵向开裂失效。
The fracture morphology, chemical composition and microstructure of bevel gears were analyzed by scanning electron microscope, di- rect reading spectrometer and metallographic microscope. Results showed that the chemical composition and microstructure matched the techni- cal requirements. The crack source was in the subsurface and there were oxidizing slag inclusions formed by such elements as O, Al, Ca and Mg. Besides, the center of the bevel gear had a serious band segregation, which deteriorated the mechanical properties of the materials. Fur- thermore, martensite transformation occurred in the secondary layer of the crack source earlier than that in the surface layer and meanwhile it was on the variable diameter interface, which had a greater stress concentration and led to the failure of its longitudinal cracking.
作者
李早
南红艳
LI Zao, NAN Hong- yan(College of Material Science and Engineering, Henan Polytechnic University, Jiaozuo 454000, Chin)
出处
《材料保护》
CAS
CSCD
北大核心
2018年第2期130-132,共3页
Materials Protection
关键词
锥齿轮
裂纹
失效分析
带状组织
夹杂物
bevel gear
cracks
failure analysis
band structure
inclusion
