摘要
对真空电子束焊接后的Ti-22Al-25Nb/Ti60双合金盘试样进行了退火处理和热暴露试验,采用OM、SEM和TEM观察了接头的显微组织。对不同状态下的双合金试样进行了室温拉伸试验,并观察了拉伸断口形貌。结果表明:退火和热暴露会促使焊接过程形成的亚稳相分解。与退火态相比,热暴露态焊缝熔合区亚稳β相和Ti60热影响区α'相分解程度增加,热暴露后Ti-22Al-25Nb合金热影响区有细小的O相析出。焊态下拉伸试样发生脆断,退火后双合金试样强度有较大提升,并有一定的拉伸塑性。热暴露后双合金试样强度进一步提高,拉伸塑性较退火态变化不大。
The annealing and heat exposure tests of Ti-22Al-25Nb/Ti60 dual-alloy disk specimens prepared by vacuum electron beam welding were carded out. The microstructure of the joints was observed by OM, SEM and TEM. The tensile tests of dual-alloy specimens at room temperature were carried out under different conditions and the tensile fi-acture morphologies were observed. The results show that the annealing and heat exposure can promote the decomposition of metastable phases formed in welding process. Compared with the annealed state, the decomposition degrees of metastable 13 phase in fusion zone and α＇ phase in Ti60 heat affected zone increase, and there are f＇me O-phase precipitates in the heat affected zone of Ti-22Al-25Nb alloy after heat exposure. The brittle fracture of the tensile specimen occurs in weld state. After annealing, the strength of the dual-alloy specimen increases and the specimen has certain tensile plasticity. The strength of the dual-alloy specimen is further improved after thermal exposure, and the plasticity doesn＇t change obviously compared with that of armealled state.
出处
《热加工工艺》
CSCD
北大核心
2017年第7期83-86,共4页
Hot Working Technology
