退火工艺对CLF-1低活化钢组织和力学性能的影响

Effect of annealing process on microstructure and mechanical properties of CLF-1 low activation steel

采用光学显微镜、透射电镜和力学性能测试等研究了完全退火和等温退火对CLF-1低活化钢组织和力学性能的影响。结果表明:CLF-1钢经完全退火和等温退火热处理后,微观组织均由回火马氏体转变为全等轴铁素体,晶粒均匀,晶界和晶内尺寸较大的棒状析出物由Fe、Cr、W、C组成,晶内细小的球状析出物由C、Ta、V组成;两种退火工艺均能降低CLF-1钢的硬度、屈服强度和抗拉强度,且伸长率可提高至30%以上,能够满足大塑性变形要求;相同厚度CLF-1钢,在满足大塑性变形的要求下等温退火可明显缩短热处理时间约9 h。

The effects of full annealing and isothermal annealing on microstructure and mechanical properties of CLF-1 low activation steel were studied by means of optical microscope, transmission electron microscopy and mechanical properties test. The results show that after full annealing and isothermal annealing, the microstructure of the CLF-1 steel is transformed from tempered martensite to uniform equiaxial ferrite, the grain size of the CLF-1 steel is uniform, and the rod-shaped precipitates with large grain size in the grain boundary and grain are composed of Fe,Cr,W and C, and the fine spherical precipitates in the grains are composed of C, Ta and V. The hardness, yield strength and tensile strength of the CLF-1 steel can be reduced by both annealing processes, and the elongation can be increased to more than 30%, which can meet the requirements of large plastic deformation. The heat treatment time of the CLF-1 steel with the same thickness can obviously shorten by about 9 h by isothermal annealing treatment under the condition of meeting the requirements of large plastic deformation.