回火参数对NiCrMoV转子钢焊缝时效韧性的影响  

Influence of tempering parameter on aged toughness of welding joint of Ni-Cr-Mo-V turbine rotor steel

作　　者：张伯奇[1] 蔡志鹏[1] 吴健栋[1] 潘际銮[1] 刘霞 乔尚飞 许晓进 霍鑫 沈红卫 

机构地区：[1]清华大学机械工程系先进成型制造教育部重点实验室,北京100084 [2]上海汽轮机厂工艺处,上海200240

出　　处：《电焊机》2013年第12期27-32,共6页Electric Welding Machine

摘　　要：为了揭示回火参数对耐热钢焊缝时效韧性的影响机理,针对采用不同回火参数处理的超临界汽轮机低压转子模拟件焊缝进行了时效韧性的研究。研究发现当回火温度利于碳化物析出聚集时,经过350℃×3 000 h时效后室温冲击韧性明显下降。通过对金相试样进行扫描电镜观察发现,时效后试样中的析出物较时效前显著增加。透射电镜观察发现析出物聚集长大后基体内的位错密度明显下降,因此热强性退化。若适当提高回火温度,经过相同的时效处理后仍然能够保持较高的冲击韧性,且析出物没有明显变化。由此证明,回火参数对碳化物析出行为的作用是其影响时效韧性的主要途径。本研究可为回火参数的优化提供一定参考。In order to study how tempering parameter influence on aged toughness of welding joint of heat resistance steel,the research on aged toughness of some welding joints from simulated supercritical steam turbine low pressure rotor which have been tempered with different parameters has been done.It has been found that when the tempering temperature is suitable for precipitation and aggregation of carbides,the room temperature impact properties of those welding joints will obviously decrease after 350 ℃×3 000 h ageing treatment.It has been proved by scanning electron microscope(SEM) observation that the amount of carbides gets much larger after ageing treatment than before.However,the property of impact toughness can be maintained and the amount of carbides can be controlled after the same ageing treatment if the tempering temperature increases appropriately.In conclusion,the effect to the precipitation of carbides is the primary factor of the influence of tempering parameter on aged toughness.Maybe this research can be used for optimizing the tempering parameter.

关 键 词：回火参数 碳化物 时效韧性 

分 类 号：TG441.8[金属学及工艺—焊接]