热处理工艺对Ti-6Al-4V ELI合金厚截面锻件力学性能的影响

Effects of Heat Treatment Processes on Mechanical Properties of Ti-6Al-4V ELI Alloy Thick Section ForgingsWang Xinnan,Zhu Zhishou,Shang Guoqiang,Xin Yunpeng,Zhu Liwei,Li Jing,

摘要:

针对损伤容限型Ti-6Al-4V ELI合金δ200mm厚截面锻件,开展了β热处理工艺和准β热处理工艺试验,对比分析了热处理工艺对锻件的强度、塑性、断裂韧度、疲劳裂纹扩展速率的影响。研究结果表明,随着第一重退火温度从T_b+15℃升高到T_b+30℃、T_b+60℃,锻件塑性下降明显。准β热处理工艺的塑性明显优于β热处理工艺,源于其β晶粒尺寸较小。强度、断裂韧度和疲劳裂纹扩展速率对β热处理工艺温度不敏感。为达到良好的强度-塑性-韧性的综合性能匹配,Ti-6Al-4V ELI钛合金厚截面锻件宜采用较低热处理温度(如T_β+15℃)的β热处理工艺或准β热处理工艺。

Abstract:

The influence of β heat treatment and quasi-β heat treatment on strength, plasticity, fracture toughness and fatigue crack propagation rate of damage-tolerant titanium alloy Ti-6Al-4V ELI thick section forgings have been studied. The results show that, the increasing of the first annealing temperature from T_b+15℃ to T_b+30℃, T_b+60℃ will lead to lower plasticity observably.