锻造温度对Ti6246合金饼坯组织和力学性能的影响

摘要

对φ200 mm×80 mm Ti6246合金棒坯在985℃(β锻造)、935℃(近β锻造)、900 ℃(α+β锻造)3种温度下进行锻饼试验,考察锻造温度对饼坯显微组织和力学性能的影响.结果表明:采用β锻造工艺,获得的显微组织为片层状α相+β转变组织;采用近β锻造工艺,可获得由球形α相+片层状α相+β转变组织构成的“三态组织”;采用α+β锻造工艺,可获得与原始组织相同的球状α相+β转变组织,但锻造后球状α相含量减少.随着锻造温度降低,Ti6246合金饼坯的室温和高温抗拉强度及屈服强度呈现先降低再升高的趋势,伸长率无显著变化;高温蠕变性能无明显变化趋势;427℃下热暴露100 h后,室温抗拉强度和屈服强度呈现先升高再降低的趋势,塑性指标无显著变化.%Ti6246 alloy bar of φ200 mm× 80 mm was processed into forging pancake.Three forging processes were hired of 985 ℃ (β forging process),935 ℃ (near β forging process) and 900 ℃ (α +β forging process).The results show that microstructure changes obviously during the decrease of the forging temperature.The β forging process is used to obtain the lamellar α phase +β transition microstructure.By using the near β forging process,the structure of spherical α + lamellar α +β transition microstructure is obtained.The α +β forging process is used to obtain the same spherical α phase and β transition structure as the original structure,but the content of the spherical α phase after forging is less.With the decreasing of the forging temperature,the room and high-temperature tensile strength and yield strength of the samples decrease at first and then increase,while plastic property does not change significantly.The high-temperature creep property has no obviously change.Mter thermal exposure 100 h at 427 ℃,the tensile strength and yield strength show a trend of increasing and then decreasing with the decreasing of forging temperature,while plastic property has little changed.