采用化学成分分析、宏观和微观检验以及能谱仪分析等方法对发生剪切开裂的SUS420J1马氏体不锈钢热轧钢板的成分和显微组织进行了分析。结果表明: 该钢板的显微组织由铁素体基体、δ铁素体相和碳化物组成,碳化物主要以网状分布于晶界和以链状分布于相界,阐述了马氏体不锈钢产生剪切开裂的机理,并提出了解决问题的建议。

The microstructure of martensitic stainless steel with cracks produced during shearing was investigated by means of chemical composition analysis,optical microscope,scanning electron microscopy and energy spectrometer. The results showed that the microstructure was mainly made up of ferrite matrix,δ ferrite phase and carbides,and the carbides were mainly distributed on the grain boundary as reticulation and phase boundary as chain. Based on the test results and the deformation characterization of the steel in shearing,the mechanism of shearing cracking was explained,and suggestions was given to resolve the problem.