轧制温度对TA31钛合金热轧板材组织与性能的影响  

Effect of rolling temperature on microstructure and properties of TA31 titanium alloy hot rolled plate

作　　者：张关梅 黄海广[1,3] 张浩泽 史亚鸣 张玉勤 蒋业华[1,2] ZHANG Guan-mei;HUANG Hai-guang;ZHANG Hao-ze;SHI Ya-ming;ZHANG Yu-qin;JIANG Ye-hua(School of Materials Science and Engineering,Kunming University of Science and Technology,Kunming 650093,China;National-local Joint Engineering Laboratory of Metal Advanced Solidification Forming and Equipment Technology,Kunming University of Science and Technology,Kunming 650093,China;Engineering Technology Research Center of Titanium Products and Application of Yunnan Province,Chuxiong 651209,China)

机构地区：[1]昆明理工大学材料科学与工程学院,云南昆明650093 [2]昆明理工大学金属先进凝固成形及装备技术国家地方联合工程实验室,云南昆明650093 [3]云南省钛材应用产品工程技术研究中心,云南楚雄651209

出　　处：《塑性工程学报》2022年第11期224-232,共9页Journal of Plasticity Engineering

基　　金：国家重点研发计划(2016YFB0301200)。

摘　　要：利用真空自耗电弧炉和电子束冷床炉熔铸了Ti-6Al-3Nb-2Zr-1Mo(TA31)合金扁锭,通过铸锭免锻造直接轧制工艺制备了热轧板材,研究了不同轧制温度(900、950和1000℃)对板材组织演变和力学性能的影响及机理。结果表明,TA31合金扁锭为魏氏组织,主要由片层状α集束和少量β晶界组成。在900℃轧制后板材主要由条带状α相和少量β转变组织组成。当轧制温度升高至950℃时,条带状α相转变为等轴α相,少量β相分布在晶间。当轧制温度进一步升高至1000℃时,部分等轴α相转变为β相,轧后冷却,组织由等轴α相、片层状和针状α相及少量β转变组织组成。随轧制温度的升高,板材抗拉强度和屈服强度下降,而断后伸长率和冲击吸收能量逐渐增大,断口形貌由韧性断裂逐渐变为微孔聚集型断裂。综合分析表明,短流程直接轧制工艺制备TA31合金板材的适宜热轧温度为950℃左右,此时抗拉强度、屈服强度、断后伸长率和冲击吸收能量平均值分别为978 MPa、831 MPa、13%和53 J。Ti-6Al-3Nb-2Zr-1Mo(TA31)alloy flat ingots were casted by vacuum consumable arc furnace(VAR)and electron beam cooling bed(EB)furnace.The hot rolled plate was prepared by direct rolling process without forging,and the influence and mechanism of different rolling temperatures(900,950 and 1000℃)on microstructure evolution and mechanical properties of plate were studied.The results show that the TA31 alloy flat ingot is widmanstatten structure,which is mainly composed of lamellarαclusters and a fewβgrain boundaries.After rolling at 900℃,the plate is mainly composed of bandedαphase and a small amount ofβtransformation structure.When the rolling temperature increases to 950℃,the bandedαphase transforms into equiaxedαphase,a small amount ofβphase is distributed between grains.When the rolling temperature further increases to 1000℃,part of equiaxedαphase transforms intoβphase.When the plate is cooled after rolling,the microstructure is consisted of equiaxedαphase,lamellar and needle-likeαphase and a small amount ofβtransformation structure.With the increase of rolling temperature,the tensile strength and yield strength of plate decrease,while the elongation after fracture and impact absorption energy increase gradually.The fracture morphology gradually changes from ductile fracture to micropore aggregation fracture.The comprehensive analysis shows that the optimum rolling temperature for the preparation of TA31 alloy plate is about 950℃,and the average values of tensile strength,yield strength,elongation and impact absorption energy are 978 MPa,831 MPa,13%and 53 J,respectively.

关 键 词：TA31钛合金 免锻直轧 热轧板材 组织演变 力学性能 

分 类 号：TG1423[一般工业技术—材料科学与工程]