固溶时效及预拉伸变形对Ti-5.5Al-2Zr-1Mo-2.5V合金管材组织演化及强韧性的影响  

Impacts of solution aging treatment and prestretching on microstructure evolution and mechanical properties of Ti-5.5Al-2Zr-1Mo-2.5V alloy for petroleum pipe

作　　者：伍贵成 刘会群[2,3] 冯春 李睿哲[5] 易丹青 WU Gui-cheng;LIU Hui-qun;FENG Chun;LI Rui-zhe;YI Dan-qing(School of Mechanical and Electrical Engineering,Central South University,Changsha 410083,China;School of Materials Science and Engineering,Central South University,Changsha 410083,China;State Key Laboratory of Powder Metallurgy,Central South University,Changsha 410083,China;Tubular Goods Research Institute of CNPC,Xi’an 710065,China;Department of Safety and Environment Supervision,Shaanxi Provincial Natural Gas Co.,Ltd.,Xi’an 710016,China)

机构地区：[1]中南大学机电工程学院,长沙410083 [2]中南大学材料科学与工程学院,长沙410083 [3]中南大学粉末冶金国家重点实验室,长沙410083 [4]中国石油天然气集团公司管材研究所,西安710065 [5]陕西省天然气股份有限公司安全与环境监察部,西安710016

出　　处：《中国有色金属学报》2022年第3期741-751,共11页The Chinese Journal of Nonferrous Metals

基　　金：国家科技重大专项(2016ZX05020-002);中国石油天然气集团公司科技开发项目(2018D-5010-08)。

摘　　要：本文研究了固溶时效及固溶预拉伸时效对挤压态Ti-5.5Al-2Zr-1Mo-2.5V钛合金管材微观组织演变、相组成及室温力学性能的影响。结果表明:高温固溶过程中,片状α相内缠结位错通过运动及反应演化成位错阵列,进而形成亚晶界,三角亚晶界形成热沟槽并扩展造成片状α相断裂。同时,淬火以及淬火后预拉伸引入的大量缺陷成为后续时效过程次生α相析出的形核位点,进而诱导次生α相数量增加、尺寸变小。淬火试样在450℃时效2 h后室温屈服强度提高30%,达到1064 MPa,同时还具有10.5%的断裂总伸长率;而2.5%预拉伸时效样品屈服强度提升53%,达到1260 MPa,但伸长率下降至4.8%。The influence of solution aging and pre-stretching aging on microstructure evolution and tensile properties of the extruded Ti-5.5Al-2Zr-1Mo-2.5V titanium alloy pipe was investigated.The results indicate that the tangled dislocations within the lamellarαphase evolves into dislocation arrays through movement and reaction,then forms into the subgrain boundary,and the thermal groove develops at the triangle boundary of the subgrain gave rise to the lamellarαphase breaking during the solid solution treatment.Meanwhile,a large quantity of defects introduced by quenching and pre-stretching become nucleation sites of the precipitation of secondaryαphase during subsequent aging,which induces the increasing number and lower size of secondaryαphase.After aging at 450℃for 2 h,the yield strength of the quenching sample increases by 29%to 1064 MPa,and the elongation remains at 10.5%;while 2.5%pre-stretching brings about 53%increment of the yield strength,but the elongation decreases to 4.8%.

关 键 词：近α钛合金管材 固溶时效 预拉伸 微观组织 强韧性 

分 类 号：TG146.23[一般工业技术—材料科学与工程]