铸坯斜轧穿孔制备大口径TA31钛合金无缝管材  

Preparation of large-diameter TA31 titanium alloy seamless pipe by directly cross rolling and perforating casting blanks

作　　者：张浩泽 余堃 钟海 姜浩 ZHANG Haoze;YU Kun;ZHONG Hai;JIANG Hao(School of Materials Science and Engineering,Kunming University of Science and Technology,Kunming 650093,China;Yunnan Titanium Industry Co.Ltd.,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]云南钛业股份有限公司,云南楚雄651209

出　　处：《兵器材料科学与工程》2022年第3期35-41,共7页Ordnance Material Science and Engineering

基　　金：云南省重大科技专项(2018ZE002)。

摘　　要：用真空自耗电弧炉+电子束冷床炉熔铸TA31钛合金(Ti-6Al-3Nb-2Zr-1Mo)圆锭,通过铸坯直接斜轧穿孔制备出?538 mm×30 mm大口径无缝管,研究不同退火温度(850、900、950℃)对无缝管组织演变、织构和力学性能的影响。结果表明:铸坯直穿无缝管材表面质量良好,外径尺寸精度高但壁厚偏厚;轧制态无缝管为变形的魏氏组织,主要由片层状α相集束和晶界α相组成,退火处理后片层状初生α相减少,原始β相晶界部分溶断,组织逐渐均匀化并转变为网篮组织和魏氏组织的结合体;宏观织构以基面(0001)织构为主,随退火温度升高,织构锐利程度先增后减,而管材抗拉强度与屈服强度小幅增加,但塑性不变,适宜退火温度约为900℃,此时抗拉强度、屈服强度和伸长率平均值分别为892、825 MPa和11%。By directly cross piercing the TA31(Ti-6Al-3Nb-2Zr-1Mo)titanium alloy ingot which was casted by a vacuum consumable electric arc furnace and an electron beam cooling bed furnace,a?538 mm×30 mm large-diameter seamless pipe was obtained.The effects of different annealing temperatures(850℃,900℃,950℃)on the microstructure,texture and mechanical properties of seamless pipes were studied.The results show that the surface quality of the seamless pipe is good,the outer diameter dimension accuracy is high,but the wall thickness is too thick.The as-rolled seamless pipe is deformed widmanstatten structure,which is mainly composed of lamellaeα-phase colonies and originalβ-phase grain boundary composition.After annealing,the lamellar primaryα-phase decreases and the originalβ-phase grain boundaries are partially dissolved.The microstructure is gradually homogenized and transformed into a combination of basket structure and widmanstatten structure.The macroscopic texture is dominated by the basal plane(0001)texture.With the increase of annealing temperature,the sharpness of the texture increases first and decreases later,while the tensile strength and yield strength of the pipe increase slightly,but the plasticity index is basically unchanged.The suitable annealing temperature is about 900℃,and the average values of tensile strength,yield strength and elongation are 892 MPa,825 MPa and 11%,respectively.

关 键 词：铸坯斜轧穿孔 大口径无缝管 TA31钛合金 织构 力学性能 低成本 

分 类 号：TG146.23[一般工业技术—材料科学与工程] TG335[金属学及工艺—金属材料]