货叉矫直断裂原因分析
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摘要
某货叉生产公司在对热处理后的货叉进行矫直时,发生矫直断裂现象。通过对生产工艺了解及断口形貌观察,结合化学成分、洛氏硬度、低倍组织、非金属夹杂物、显微组织及扫描电镜检验等检验结果的综合分析,最终得出货叉矫直断裂系其钢材内部存在超尺寸非金属夹杂物,破坏了钢材基体的连续性且易形成应力集中。同时由于此货叉回火硬度过高及显微组织异常,在较大的矫直力作用下,最终导致货叉矫直时断裂。在对货叉矫直断裂原因分析后提出了几点建议。
The straightening fracture occurs when a fork production company straightens the fork arms after heat treatment. Through the observation of fracture morphology and understanding of production process,combined with comprehensive analysis of chemical composition,hardness,macrostructure,non metallic inclusions,microstructure test and SEMtest results,it is found that fork straightening fracture results from the presence of extra non-metallic inclusions inside the steel,which destroys the continuity of steel matrix and easily forms stress concentration. At the same time,due to the high hardness and abnormal microstructure of fork,the fork eventually breaks during straightening. After analyzing the cause of the fork 's straightening fracture,several suggestions are put forward.
The straightening fracture occurs when a fork production company straightens the fork arms after heat treatment. Through the observation of fracture morphology and understanding of production process,combined with comprehensive analysis of chemical composition,hardness,macrostructure,non metallic inclusions,microstructure test and SEMtest results,it is found that fork straightening fracture results from the presence of extra non-metallic inclusions inside the steel,which destroys the continuity of steel matrix and easily forms stress concentration. At the same time,due to the high hardness and abnormal microstructure of fork,the fork eventually breaks during straightening. After analyzing the cause of the fork 's straightening fracture,several suggestions are put forward.
引文
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[4]韩晓乾,袁利民,张政玮.55Cr Mn A弹簧扁钢淬火硬度低实例分析[J].金属加工-热加工,2016,(15):51~52.
[5]方国章,李祥才.50Cr VA弹簧扁钢淬透性的研究[J].安徽冶金,2014,(1):10~13.