热处理制度对Ti555211合金组织和性能的影响

研究了一种新型近β钛合金（Ti555211），该合金具有优异的塑性加工能力、高比强度以及优良的综合性能，在航天航空及化工领域上有广泛的应用。通过3×3正交试验，研究了两阶段不同处理（固溶温度、失效温服、时效时间）对Ti555211钛合金力学性能和显微组织的影响。结果表明，随着固溶温度的升高和时效温度的降低，合金强度提高。延伸率随着固溶温度的降低和时效温度的升高而增大。经820 ℃/2 h空冷和580 ℃/12 h空冷处理后，合金具有较好的强塑性，抗拉伸强度达到1333 MPa，较同类合金强度指标（1080 MPa）高出20%；延伸率为12%，较同类合金塑性指标（5%）高出140%。

Effect of Heat Treatment Process on Microstructure and Mechanical Property of Ti555211 Titanium Alloy

A new type of near-β titanium alloy (Ti555211) was investigated. This alloy has excellent plasticity, high specific strength, and excellent comprehensive properties, which is widely used in the aerospace and chemistry industries. Through the 3×3 orthogonal experiments, the influences of different stages of two-step annealing treatment (solution temperature, aging temperature, aging time) on the mechanical properties and microstructures of Ti555211 titanium alloy were investigated. Results show that with increasing the solution temperature and decreasing the aging temperature, the alloy strength is increased. The elongation is increased with decreasing the solution temperature and increasing the aging temperature. After treatment of 820 °C/2 h/air cooling and 580 °C/12 h/air cooling, the alloy has better plasticity, and its tensile strength reaches 1333 MPa, which is higher than the strength index (1080 MPa) of similar alloys by 20%. The elongation of the Ti555211 titanium alloy is 12%, which is higher than the plasticity index (5%) of similar alloys by 140%.