特种阀门用高强韧性超细晶-纳米晶T91钢力学性能及组织热稳定性的研究  

The Mechanical Properties and Thermal Stability of Ultrafine-grained or Nanocrystalline T91 Special Valve Steel with High Strength and Toughness

作　　者：王坤[1] 张俊平[1] 童玉林 范作强 林继兴[1] 郝汀 WANG Kun;ZHANG Jun-ping;TONG Yu-lin;FAN Zuo-qiang;LIN Ji-xing;HAO Ting(Zhejiang Industry&Trade Vocational College,Wenzhou,325003,China;Xingji Electric Appliances Co.,Ltd.,Wenzhou,325037,China;Institute of Solid State Physics,Chinese Academy of Sciences,Hefei,230031,China)

机构地区：[1]浙江工贸职业技术学院,浙江温州325003 [2]兴机电器有限公司,浙江温州325037 [3]中国科学院固体物理研究所,安徽合肥230031

出　　处：《浙江工贸职业技术学院学报》2018年第2期52-56,共5页Journal of Zhejiang Industry & Trade Vocational College

基　　金：2016年温州市科技计划项目"特种阀门用高强韧性超细晶/纳米晶铁素体不锈钢的制备及其性能优化研究"(G20160022)

摘　　要：当前,严苛的使用环境对阀门材料的性能提出了更高的要求。通过内转角为90°的等通道转角挤压(ECAP)模具对T91钢进行1道次挤压以细化晶粒,结果显示,经过挤压后原始材料中的等轴晶粒发生明显变形,粗大板条状马氏体组织也得到细化。力学性能测试显示,材料屈服强度和抗拉强度同步提高,分别由630 MPa和735MPa增加至1000 MPa和1025 MPa。但延伸率则由31.5%明显降至17.6%,断口呈现部分脆性断裂的现象。内耗测试和TEM分析显示,经过1道次挤压后试样,在700oC时仅发生位错回复而无再结晶晶粒生成,其细化后的纳米晶组织呈现出一定的热稳定性。In this work,T91 steel was processed through equal-channel angular pressing(ECAP)method for one pass using ECAP equipment with an inner angle of 90°die as grain refinement could meet the high demand set on the special valve material used in severe environment.After ECAP,the equiaxed grains were deformed and the coarsening lath martensite was refined.As a result,the yield strength and tensile strength were increased simultaneously from 630 MPa and 735 MPa to 1000 MPa and 1025 MPa,respectively.However,the tensile elongation decreased from 31.5%to 17.6%and the fracture surface presented some brittle fracture phenomena.The internal friction and TEM results show that the T91 steel subjected to ECAP for one pass is thermally stable in some extent as only the dislocation recovery but not the recrystallization took place after the annealing at 700oC for 2h.

关 键 词：ECAP T91钢 晶粒细化 内耗 

分 类 号：TG142[一般工业技术—材料科学与工程]