桁架用Nb-Mo微合金中锰钢强化机理及碳化物析出行为
Strengthening mechanism and carbide precipitation behavior of Nb-Mo microalloyed medium manganese steel for crossing frame truss
刘敏 1郑志鹏 2甘利红 1刘胤辰 1刘震 1张阳 3冯波 3刘春泉4
作者信息
- 1. 国网湖北省电力有限公司咸宁供电公司,湖北咸宁 437000
- 2. 湖北香城智能机电研究院有限公司,湖北咸宁 437000
- 3. 湖北科技学院工程技术研究院,湖北咸宁 437000
- 4. 湖南工学院材料科学与工程学院,湖南衡阳 421002
- 折叠
摘要
探讨了自制移动式伞型跨越架桁架用Nb-Mo微合金中锰钢在快速加热淬火和奥氏体逆相变(RH-ART)处理后的强化机理和碳化物析出行为.结果表明,微合金试验钢中的(Nb,Mo)C不仅在铁素体晶粒内部以及位错线上析出,起到阻碍位错移动的作用,进而使得试验钢强度提升;并且(Nb,Mo)C在奥氏体与铁素体的晶界处析出,起到拖拽作用,抑制了奥氏体晶粒粗化速率.同时,在快速加热淬火和奥氏体逆相变处理后,大量的纳米级渗碳体析出,这有利于增加中锰钢中残留奥氏体含量.此外,在690℃温度下进行奥氏体逆相变,此时基体存在一定量的亚稳态碳化物颗粒,这有助于提高奥氏体的形核速率,还降低了 C的平均扩散距离,即提高了奥氏体的生长速率,从而获得更多含量的残留奥氏体.试验钢具有超过49％的残留奥氏体含量,展现出了拉伸强度为779 MPa,断后伸长率为77.7％的优异综合力学性能.
Abstract
After rapid heating quenching and austenite reverse phase transformation(RH-ART)treatment,the strengthening mechanism and carbide precipitation behavior of Nb-Mo microalloyed medium manganese steel used for self-made mobile umbrella type crossing frame truss were investigated.The results show that(Nb,Mo)C in the microalloyed experimental steel not only precipitates inside the ferrite grains and on dislocation lines,acting as a barrier to dislocation movement,thereby improving the strength of the experimental steel;but also precipitates at the grain boundaries between austenite and ferrite,playing a dragging effect role and suppressing the austenite grain coarsening.Meanwhile,after rapid heating quenching and austenite reverse phase transformation treatment,a large amount of nanoscale cementite precipitates,which is beneficial to increase the retained austenite content in medium manganese steel.In addition,when austenite reverse phase transformation is carried out at a temperature of 690 ℃,there is a certain amount of metastable carbide particles in the matrix,which helps to improve the nucleation rate of austenite and also reduces the average diffusion distance of C,which increases the growth rate of austenite and obtains more retained austenite content.The tested steel exhibites excellent comprehensive mechanical properties with a retained austenite content of more than 49％,a tensile strength of 779 MPa and an elongation at break of 77.7％.
关键词
跨越架/中锰钢/强韧机制/纳米碳化物/析出物Key words
crossing frame/medium Mn steel/strengthening mechanism/nanometer-sized carbides/precipitation引用本文复制引用
基金项目
湖北省自然科学基金青年面上项目(2021CFB009)
湖南省科技人才托举工程"小荷"科技人才专项(2023TJ-X10)
湖南省自然科学基金(2023JJ50108)
湖南工学院青年自科培育项目(2022HY007)
出版年
2024
NETL
NSTL
万方数据