摘要
采用OM、SEM等微观组织分析手段研究了H13钢铸态组织和扩散退火过程中显微组织和成分偏析的演变规律。结果表明,H13钢电渣锭的铸态组织为粗大马氏体+贝氏体+液析碳化物,枝晶间和晶界处分布着高熔点液析碳化物和大尺寸二次碳化物,存在严重的枝晶偏析和成分偏析。随着扩散退火温度的升高,组织中的碳化物逐渐回溶到基体中,枝晶内的碳化物溶解速度和元素扩散速度明显快于枝晶间和晶界处,会优先达到成分均匀性要求。在1240℃进行扩散退火时,枝晶间的大尺寸二次碳化物几乎全部回溶到基体中,晶界处的高熔点液析碳化物数量明显减少,仅残存少量未完全溶解的小颗粒液析碳化物。从节能和提高成材率方面考虑,建议H13钢较佳的扩散退火工艺为1240℃×10 h。
Microstructure of as-cast H13 steel and microstructure evolution and component segregation during diffusion annealing were studied by means of OM and SEM.The results show that the as-cast microstructure of the electroslag remelt H13 steel is thick martensite+bainite+liquid-dissected carbides.High melting point liquid-dissected carbides and large size secondary carbides are distributed between dendrites and grain boundaries,and there are serious dendritic segregation and component segregation.With the increase of diffusion annealing temperature,the carbide gradually dissolve into the matrix,and the dissolution rate of carbides and the diffusion rate of elements in the dendrites are obviously faster than those at the interdendritic region and grain boundaries,which will preferentially meet the requirements of composition uniformity.When the diffusion annealing is 1240℃,the large size secondary carbides between dendrites are almost all dissolved back into the matrix,and the amount of high melting point liquid-dissected carbides at the grain boundary is obviously reduced,and only a few small particles of liquid-dissected carbides are left.For considering the energy saving and the yield improving,it is suggested that diffusion annealing at 1240℃for 10 h is better process for the H13 steel.
作者
樊明强
赵英利
李素芳
梁佳
王超
徐军君
王建强
赵峥嵘
Fan Mingqiang;Zhao Yingli;Li Sufang;Liang Jia;Wang Chao;Xu Junjun;Wang Jianqiang;Zhao Zhengrong(HBIS Group Technology Research Institute,Shijiazhuang Hebei 052165,China;HBIS Group,Shijiazhuang Hebei 050023,China;HBIS Group Zhangxuan Technology,Xuanhua Hebei 075100,China)
出处
《金属热处理》
CAS
CSCD
北大核心
2024年第1期211-214,共4页
Heat Treatment of Metals
关键词
H13钢
扩散退火
显微组织
成分偏析
液析碳化物
H13 steel
diffusion annealing
microstructure
component segregation
liquid-dissected carbides
