(1. 西北有色金属研究院 钛合金研究所, 西安 710016; 2. 宝钛集团有限责任公司, 宝鸡 721014)
摘 要: 针对Ti40合金大规格棒材锻造过程中的组织演化行为,在棒材锻造的不同阶段取样,对样品进行不同温度和不同时间的加热和保温,通过光学显微镜和EBSD测试对合金组织演化行为和再结晶机制进行分析。结果表明:Ti40合金棒材在加热保温过程中主要以晶界小晶粒长大为主,这些晶界小晶粒主要产生于锻造过程中,是依靠晶界变形从原始母晶粒上脱落产生的,这些晶粒在此后的棒材加热保温过程中长大,引起合金的组织均匀化和细化。从组织均匀性和晶粒平均尺寸考虑,合金最佳的加热工艺为1 000 ℃、4 h。
关键字: Ti40合金;热加工;组织;再结晶
(1. Titanium Alloy Research Center, Northwest Institute for Non-ferrous Metal Research, Xi’an 710016, China;
2. BaoTi Group Co., Ltd., Baoji 721014, China)
Abstract:Aiming at the microstructure evolution of Ti40 big bar, the samples cut from bar blanks with different deformation were heated at different temperatures for different times. Optical microscope and EBSD were used to analyze the microstructure evolution and recrystallization behavior. The results indicate that the microstructure evolution of Ti40 bar during heated process mainly shows the growing behavior of small grains along grain boundaries. These small grains mainly results from forging process, which mainly come from original parent grains because of the grain boundaries deformation. After forging process, these small grains grow during heating process and which cause the uniform microstructure and the decrease of the average grain size. In view of the average grain size and microstructure uniformity, the best heating process is (1 000 ℃, 4 h).
Key words: Ti40 alloy; hot working; microstructure; recrystallization