【摘要】 研究了热轧态1Cr16Co5Ni2MoWVNbN马氏体耐热钢经一道次等径角挤压（ECAP）变形+680℃×2h空冷处理后的微观结构和力学性能.结果表明:经ECAP变形后,马氏体板条大部分已碎化成亚晶粒和位错胞,第二相纳米粒子(M₂₃C₆)分布更弥散均匀;经随后的退火处理,发生了回复和部分再结晶,位错密度有所降低,形成大量尺寸仅几百纳米的等轴亚晶粒.ECAP变形后材料的屈服强度有很大提高（提高至1400 MPa）,但延伸率和静力韧度均大幅度下降（分别降至7.3%和100 MJ/m³）;随后的退火处理可恢复其塑性（15.4%）,其强度（1044 MPa）和静力韧度（181.6 MJ/m³）均较初始态（922 MPa,160.7 MJ/m³）高.更多还原

【Abstract】 The microstructures and mechanical properties of 1Cr16Co5Ni2MoWVNbN marten- site heat-resistant steel subjected to equal channel angular pressing（ECAP）for one pass and subse- quent heat treatment were investigated.It was found that most of the martensite lathes had been broken into sub-grain and dislocation cell,and the second phase nano-particles(M₂₃C₆)distributed more uniformly after ECAP deformation.By annealing at 680℃for 2 h,the dislocation density decreased and more amount of equiaxed subgrains with size of several hundred of nanometers formed, while the recovery and recrystallization occured.The yield strength of the ECAPed sample increased significantly（1400 MPa）,but its elongation and static toughness decreased a lot（7.3% and 100 MJ/m³）. After subsequent annealing treatment,both the strength and static toughness of the steel can be in- creased simultaneously（1044 MPa and 181.6 MJ/m³）in comparison with those of initial state.更多还原