等径弯曲通道变形对T250马氏体时效钢的组织和性能的影响  

Effect of Equal Channel Angular Pressing on Microstructure and Properties of T250 Maraging Steel

作　　者：席莎[1] 赵西成[1] 杨西荣[1] 亓博丽 张金龙[1] 

机构地区：[1]西安建筑科技大学冶金工程学院,陕西西安710055

出　　处：《热加工工艺》2014年第3期27-30,共4页Hot Working Technology

基　　金：陕西省教育厅专项科研计划项目(12JK0429)

摘　　要：采用等径弯曲通道变形(ECAP)工艺在室温下对固溶态的T250马氏体时效钢以C方式进行了2道次的变形,通过金相显微镜﹑透射电镜及力学性能的测试,研究了多道次ECAP变形对T250马氏体时效钢组织和性能的影响。结果表明,ECAP变形能获得较好的晶粒细化效果,经过2道次的ECAP变形后,马氏体板条变为更窄的带,板条宽度由原始的0.8μm减小到0.2μm,板条内位错密度增加,畸变严重。经2道次室温ECAP挤压变形后,马氏体时效钢的显微硬度从336.3 HV提高到419.8 HV,硬度提高24.7%,并且1道次挤压后硬度的增幅明显大于2道次。Equal channel angular pressing was successfully carried out on the solution-annealed steel with two passes at room temperature through the route C. Influences of ECAP multi-passes on microstructure and mechanical properties of T250 maraging steel were studied with metalloscope, TEM and mechanical property test. The results show that a well grain refinement can be achieved by ECAP forming. The martensite lath is elongated to more narrow bands, and the width is decreased from 0.8 μm to 0.2 μm after two passes ECAP deformation. Density of dislocations in lath is increased and distortions are serious. After two passes ECAP deformation, the microhardness is enhanced about 24.7% from 336.3 HV to 419.8HV, and the growth range of one pass is significantly greater than two pass.

关 键 词：马氏体时效钢 等径弯曲通道变形(ECAP) 微观组织 力学性能 

分 类 号：TG142.24[一般工业技术—材料科学与工程] TG376[金属学及工艺—金属材料]