(1. 西安建筑科技大学 冶金工程学院，西安 710055； 2. 宝钛集团有限公司研究院，宝鸡 721014)
摘 要: 研究一种新型β钛合金在两相区锻造后，边部、1/2R、心部组织的不均匀性对后续热处理组织性能的影响。结果表明：合金经750 ℃固溶后，3个位置组织中的初生α相分布不同，经800 ℃固溶后，β相发生不同程度的再结晶。合金经750 ℃+(510 ℃，8 h)固溶时效后，边部和1/2R处的组织出现 “β斑”现象；合金经800 ℃+ 510 ℃，8 h固溶时效后，1/2R处和心部次生α相的析出存在明显的不均匀性。时效过程中组织的不均匀性导致合金3个位置强度和断裂韧性各不相同。在(750 ℃，0.5 h，AC)+(510 ℃，8 h，AC)固溶时效条件下，合金1/2R处的综合性能实现了高强高韧的良好匹配。
关键字: β钛合金；两相区锻造；不均匀性；析出相；高强高韧
（1. School of Metallurgical Engineering, Xi’an University of Architecture and Technology, Xi’an 710055, China; 2. Institute of Baoji Titanium Industry Group Co., Ltd., Baoji 721014, China）
Abstract:The influence of inhomogeneity of original microstructures including edge, 1/2R and core of a new β titanium alloy via α+β forging process on microstructures and mechanical properties following heat treatments were investigated. The results show that the distribution of primary α phase in three locations was nonuniform after the alloy solution-treated at 750 ℃, and at 800 ℃, different degree of recrystallization occurred within β phase. The alloy solution-treated at 750 ℃ followed by aging at 510 ℃ for 8 h, the microstructure with beta fleck happened in edge and 1/2R. Under the same aging condition, when the solution treatment was taken at 800 ℃, the secondary α phase with obviously uneven distribution precipitates in 1/2R and core. This inhomogeneity of microstructures during aging treatments results in different mechanical properties both of strength and fracture toughness in three locations. The alloys treated at (750 ℃, 0.5 h, AC)+(510 ℃, 8 h, AC) acquires good strength-toughness match, and high strength and high toughness of alloy at the location of 1/2R reaches the well match of high strength and high toughness.
Key words: β titanium alloy; forged in two-phase region; inhomogeneity; precipitated phase; high strength and high toughness
