(1. 北京有色金属研究总院 有色金属材料制备与加工国家重点实验室，北京 100088；
2. 宝钛集团有限公司，宝鸡 721014)
摘 要: 采用光学显微镜、电子探针和拉伸实验研究单重退火处理对BTi-6431S合金显微组织和力学性能的影响。结果表明：随退火温度的升高，合金中的初生α相粗化，趋于等轴状，体积分数逐渐降低；β相和次生α相的体积分数增加。随退火温度的升高，合金的室温强度先升高后降低，高温强度则逐渐升高；但是室温和高温塑性均不断下降。经过980 ℃退火处理后，BTi-6431S合金获得良好的高温强度和室温塑性匹配，此时合金650 ℃的抗拉强度达到600 MPa以上，室温伸长率超过8%。
关键字: 高温钛合金；BTi-6431S合金；单重退火；显微组织；力学性能
（1. State Key Laboratory of Nonferrous Metals and Processes,
General Research Institute for Nonferrous Metals, Beijing 100088, China;
2. Baoti Group Co., Ltd., Baoji 721014, China）
Abstract:The effects of single annealing on the microstructure and mechanical properties of BTi-6431S titanium alloy were studied by OM, EPMA and tensile test. The results show that, with increasing annealing temperature, the primary α phase becomes coarse, then changes into equiaxed shape, and its volume fraction decreases gradually, while the volume fractions of β phase and secondary α phase increase. With elevating the annealing temperature, the room temperature strength increases at first and then decreases, while the high temperature strength increases gradually, but the room-temperature and high-temperature ductility decreases. After annealing at 980 ℃, BTi-6431S alloy acquires good strength at high-temperature and plasticity at room-temperature. The ultimate tensile strength at 650 ℃ can reach more than 600 MPa, and the room-temperature elongation is more than 8%.
Key words: high temperature titanium alloy; BTi-6431S alloy; single annealing; microstructure; mechanical properties
