S31042耐热钢650℃持久的析出相对持久塑性的影响  

Effect of precipitates on the creep plasticity of S31042 heatresistant steel crept at 650 ℃

作　　者：杨亚红[1] 朱丽慧[1] 王起江[2] 朱长春[3] 

机构地区：[1]上海大学上海市现代冶金及材料制备重点实验室,上海200072 [2]宝山钢铁股份有限公司,上海201900 [3]宝钢特钢有限公司,上海200940

出　　处：《钢铁》2015年第1期55-60,共6页Iron and Steel

基　　金："十二五"国家科技支撑计划资助项目(2011BAK06B04);国家自然科学基金资助项目(51171097)

摘　　要：S31042钢是一种重要的超临界和超超临界锅炉用钢。针对该钢持久塑性差的问题,采用扫描电镜和透射电镜研究了S31042钢在650℃持久前后的微观组织,主要探讨了析出相对持久塑性的影响。结果表明:持久1 608 h,S31042钢的塑性快速下降。而后塑性缓慢下降,并逐渐趋于稳定。S31042钢持久过程中主要的析出相为二次NbCrN和M23C6,长期持久会导致少量σ相和Cr3Ni2Si C的析出。S31042钢持久塑性显著下降的主要原因是由于M23C6在晶界上的析出。此外,链状M23C6、立方形M23C6以及未溶的Nb Cr N对S31042钢的持久塑性也有害。S31042 steel is an important heat-resistant steel used for super critical and ultra super critical pressure boilers. In order to analyze the poor creep plasticity of $31042 steel, the microstructure of S31042 steel before and aider crept at 650 ℃ was studied by SEM and TEM, and the effect of the precipitates on creep plasticity was discussed. The results show that the creep plasticity dropped rapidly after crept for 1608 h. Thereafter, the plasticity declined slowly with the in- crease of the creep time. Finally, it tended to be stable. The main precipitates were secondary NbCrN and M23C6 during creep. Long-term creep also resulted in the precipitation of a few Cr3Ni2SiC and o phase. The precipitation of M23C6 at the grain boundaries resulted in the dramatic decrease in the creep plasticity of S31042 steel. Chain-like M23C6, cuboids M23C6 and undissolved NbCrN were also detrimental to the creep plasticity of S31042 steel.

关 键 词：S31042耐热钢 高温持久 组织 持久塑性 

分 类 号：TG142.73[一般工业技术—材料科学与工程]