风电主轴冲击试验不合格原因分析

Disqualification cause analysis of wind turbine spindle in impact test

42Cr Mo4钢制风电调质主轴冲击试验不合格。通过断口分析、成分分析、硬度测试、金相分析等工作,对不合格的原因进行了分析。结果表明：该工件在调质处理过程中存在淬火不良组织（粒状贝氏体）,未形成理想的调质组织导致冲击试验结果不合格。建议优化热处理工艺,保证淬火冷却速度,原材料冶炼中加入B、稀土元素,以提高调质主轴冲击性能。

Impact test of a quenched and tempered 42 Cr Mo4 steel wind power spindle was failed. Through fracture analysis,chemical composition analysis,hardness test,metallographic analysis and so on,the causes of failure were analyzed. The results show that the bad quenched microstructure（ granular bainite） in the process of quenching and tempering,i. e.,no ideal quenched and tempered structure is formed,which lead to the disqualification of the impact test result. It is suggested that the heat treatment process should be optimized to ensure the cooling rate of quenching,and adding boron and rare earth elements in steelmaking to improve the impact property of the spindle.