Cr-Mo低合金钢冲击韧性异常波动原因分析

Cause Analysis of Abnormal Fluctuation of Impact Toughness of Cr-Mo Low Alloy Steel

在对某批次低合金Cr-Mo耐热钢进行-20℃低温冲击试验时发现其试验结果波动大,部分结果不能满足技术条件要求。结合该产品的实际生产及热处理工艺,对该材料进行断口宏观分析、扫描电镜及能谱分析以及金相检验。结果表明:造成该材料低温冲击韧性异常波动原因是由于存在粗大贝氏体团、混晶和局部存在异常圆形物。针对该结论,提出了在炼钢生产和后续轧制过程中的相关控制建议,以避免该材料冲击韧性异常波动情况的产生。

During the-20 ℃ low-temperature impact test of a batch of low-alloy Cr-Mo heat-resistant steel, the test results fluctuate greatly, and some test results cannot meet the technical requirements. Combined with the actual production process, chemical analysis,fracture macro analysis, SEM and EDS analysis and metallographic examination were carried out on the mentioned material. And the results show that the abnormal fluctuation of low temperature impact toughness is caused by the existence of coarse bainite lump, mixed grain and local abnormal round object. In response to this conclusion, to avoid abnormal fluctuations in the impact toughness of the material, recommendations for control methods in the steelmaking production and subsequent rolling processes are proposed.