9Cr3W3Co钢高温时效脆化现象与改进方法  

Aging embrittlement at high temperature of 9Cr3W3Co steel and its improvement method

作　　者：马龙腾[1] 刘正东[1] 白银[1,2] MA Long-teng;LIU Zheng-dong;BAI Yin(Institute for Special Steels,Central Iron and Steel ResearchInstitute,Beijing 100081,China;School of Materials Scienceand Engineering,University of Science and TechnologyBeijing,Beijing 100083,China)

机构地区：[1]钢铁研究总院特殊钢研究所,北京100081 [2]北京科技大学材料科学与工程学院,北京100083

出　　处：《材料工程》2019年第3期139-146,共8页Journal of Materials Engineering

基　　金：国家能源应用技术研究及工程示范项目(NY201501);国家高技术研究发展计划(863计划)项目(2012AA03A501)

摘　　要：采用SEM进行显微组织观察,研究导致9Cr3W3Co钢时效脆化的主要因素。采用Thermo-Calc软件,计算平衡态下不同W含量(2.36%,2.63%,2.96%,3.11%,质量分数)的9Cr3W3Co钢中析出相的含量。利用TEM,SAXS和相分析等实验手段研究时效过程中的组织演变。结果表明:9Cr3W3Co钢的冲击韧度在100h时效后的迅速降低是时效过程中大量析出的富W Laves相所造成的。平衡态的Laves相含量主要由钢中的W含量决定。时效8000h后,W含量最低的钢冲击韧度最好,同时其Laves相的尺寸最小,粗化速率最低。通过降低W含量能够抑制9Cr3W3Co钢的时效脆化。The main factor that results in aging embrittlement of 9Cr3W3Co steel was investigated through microstructure observation using scanning electron microscopy (SEM). The amount of each precipitates under equilibrium state in 9Cr3W3Co steel with different W content (W content is 2.36%, 2.63%, 2.96% and 3.11%, mass fraction) was calculated using Thermo-Calc software. The microstructure evolution during aging was studied by transmission electron microscopy (TEM), small angle X-ray scattering (SAXS) and phase analysis method. The results show that the rapid drop of impact toughness after aging for 100h is caused by the formation of Laves phase. The mass fraction of Laves phase at equilibrium state is mainly determined by the concentration of tungsten. The steel with lower tungsten content exhibits higher impact toughness after aging for 8000h,meanwhile with the smallest size and the lowest coarsening rate of Laves phase. Thus, the aging embrittlement of 9Cr3W3Co steel can be successfully suppressed by the reduction of tungsten content.

关 键 词：时效脆化 9Cr3W3Co钢 W含量 冲击韧度 

分 类 号：TG142[一般工业技术—材料科学与工程]