摘要
采用化学成分、断口形貌、显微组织、硬度检测等方法进行测试和分析,研究了扭矩仪主轴断裂的原因。结果表明:异常显微组织是造成主轴断裂的主要原因。粗大的回火马氏体和由晶界向晶内扩展的上贝氏体组织导致了裂纹的萌生和扩展,形成沿晶+准解理断口形貌;带状组织的存在增大了显微组织和硬度的不均匀性,导致了材料的各向异性,弱化了构件的服役性能;此外,由于拉应力的作用,键槽根部产生的应力集中效应也是导致构件脆性断裂的重要原因。
To study the crucial reason of fracture of the shaft of torque gauge,chemical composition,fracture morphology,metallographic analysis and hardness were investigated and analyzed. The results show that the major factor of fracture of the shaft is abnormal microstructure. The coarse tempered martensite and the upper bainite which propagates from grain boundaries towards inside of grains bring about the initiation and propagation of crack,and form the morphology along the grain boundaries and quasi-cleavage fracture. The banded structure accelerates the heterogeneity of microstructure and hardness distribution,which results in anisotropism of material and weakens the service performance of the part. In addition,due to the tensile stress,the stress concentration effect at the root of the keyway is also a vital factor of the fracture of shaft.
作者
潘树民
王小海
刘国强
项红岩
于大威
于庆峰
Pan Shumin;Wang Xiaohai;Liu Guoqiang;Xiang Hongyan;Yu Dawei;Yu Qingfeng(Inner Mongolia First Machinery Group Co.,Ltd.,Baotou Inner Mongolia 014032,China)
出处
《金属热处理》
CAS
CSCD
北大核心
2020年第5期257-262,共6页
Heat Treatment of Metals
关键词
扭矩仪主轴
显微组织
沿晶裂纹
脆性断裂
失效分析
torque gauge shaft
microstructure
intergranular crack
brittle fracture
failure analysis
