(1. 西安建筑科技大學(xué) 冶金工程學(xué)院，西安 710055； 2. 寶鈦集團(tuán)有限公司研究院，寶雞 721014)
摘 要: 研究一種新型β鈦合金在兩相區(qū)鍛造后，邊部、1/2R、心部組織的不均勻性對(duì)后續(xù)熱處理組織性能的影響。結(jié)果表明：合金經(jīng)750 ℃固溶后，3個(gè)位置組織中的初生α相分布不同，經(jīng)800 ℃固溶后，β相發(fā)生不同程度的再結(jié)晶。合金經(jīng)750 ℃+(510 ℃，8 h)固溶時(shí)效后，邊部和1/2R處的組織出現(xiàn) “β斑”現(xiàn)象；合金經(jīng)800 ℃+ 510 ℃，8 h固溶時(shí)效后，1/2R處和心部次生α相的析出存在明顯的不均勻性。時(shí)效過程中組織的不均勻性導(dǎo)致合金3個(gè)位置強(qiáng)度和斷裂韌性各不相同。在(750 ℃，0.5 h，AC)+(510 ℃，8 h，AC)固溶時(shí)效條件下，合金1/2R處的綜合性能實(shí)現(xiàn)了高強(qiáng)高韌的良好匹配。
關(guān)鍵字: β鈦合金；兩相區(qū)鍛造；不均勻性；析出相；高強(qiáng)高韌
（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
