摘要
采用吉帕级超高压烧结粉末冶金方法制备了14Cr-ODS钢,通过致密度、SEM、TEM、硬度以及拉伸实验等方法研究了高压烧结工艺对ODS钢微观组织及力学性能的影响。研究表明,通过高压烧结可获得主要析出相为Ti_(2)O_(3)、晶粒均匀、平均晶粒尺寸小于300 nm的细晶14Cr-ODS钢,其Vickers硬度可达604 HV,抗拉强度接近1.5 GPa,显著优于常规烧结方法制备的相近成分ODS钢的性能。得益于超高压力产生塑性变形对晶粒形核和原子扩散的综合影响,超高压烧结可在较低烧结温度和较短烧结时间的工艺下,获得致密度超过99%的力学性能优异的ODS钢试样。
Due to its superior mechanical, processing, and service properties, oxide dispersion-strengthened(ODS) alloy(particularly Fe base ODS steel) has emerged as the most promising future candidate for advanced reactor structural materials. However, there are some problems with hot isostatic pressing sintering ODS steels, such as higher sintering temperature, longer sintering time, and relatively coarse grains. In this work, 14Cr-ODS steels were prepared by ultra-high pressure sintering with a sintering pressure of 3, 4, and 5 GPa, respectively. The microstructure and mechanical properties of the ultrahigh pressure sintered 14Cr-ODS steel samples were characterized by density test, SEM, TEM, hardness test, and tensile test. Based on the contrast analysis of microstructure and mechanical properties,the effect of sintering pressure on the microstructure and mechanical properties of ultra-high pressure sintered 14Cr-ODS steel was investigated, and the effect mechanism was thoroughly analyzed. Analysis results show that the main oxide precipitate of ultra-high pressure sintered 14Cr-ODS steel is Ti_(2)O_(3), and the average grain size of 14Cr-ODS steel prepared by ultra-high pressure sintering is less than 300 nm,which is approximately 5% of the average grain size of 14Cr-ODS steel prepared by conventional hot isostatic pressing sintering. The average grain size of samples prepared by ultra-high pressure sintering decreased initially and then increased as sintering pressure increased. The Vickers hardness of ODS steel samples sintered at 4 GPa can reach 604 HV, and the tensile strength is approximately 1.5 GPa, which is 1.6 times than that of 14Cr-ODS steel samples with a similar composition prepared by conventional hot isostatic pressing sintering. Ultra-high pressure sintered 14Cr-ODS steel with good sintering formability and a density greater than 99% can be obtained at lower sintering temperatures and shorter sintering times. Its excellent performance can be mainly associated with the comprehensive influence of the plastic deformation effect produced by ultra-high pressure sintering on grain nucleation and atom diffusion in sintered samples.
作者
王韬
龙弟均
余黎明
刘永长
李会军
王祖敏
WANG Tao;LONG Dijun;YU Liming;LIU Yongchang;LI Huijun;WANG Zumin(State Key Laboratory of Hydraulic Engineering Simulation and Safety,School of Materials Science and Engineering,Tianjin University,Tianjin 300354,China;Nuclear Power Institute of China,Chengdu 610041,China)
出处
《金属学报》
SCIE
EI
CAS
CSCD
北大核心
2022年第2期184-192,共9页
Acta Metallurgica Sinica
基金
国家重点研发计划项目No.2017YFB0701801
国家自然科学基金项目Nos.51974199和U1960204。
