热处理工艺对2A14锻件组织和性能的影响

针对生产中2A14壳体伸长率低导致力学性能不合格,对2A14锻件进行退火、分级时效热处理试验,测试力学性能及金相组织.结果表明:2A14锻件固溶前的退火处理能改善锻件纵横向性能,促进第二相的溶解:时效保温时间对锻件力学性能影响很大,随保温时间的延长,强度、硬度增加,伸长率则是先升高后降低,保温时间为4.5～5 h时综合性能最好;分级时效能改善锻件组织及性能,优化出100℃×2 h空冷+155℃×4.5 h空冷韵分级时效工艺,用此工艺处理2A14锻件,伸长率提高了170%～300%,强度、硬度仍保持较高水平.

Effect of Heat Treatment Technology on Microstructure and Mechanical Properties of 2A14 Alloy Forgings

By annealing and re-aging test of 2A14 aluminium alloy forgings, the microstructure, mechanical properties and hardness were measured. The results show that annealing before dissolving can improve the longitudinal and transversal properties of the forging, and promote the dissolution of second phases; the aging time influences mechanical properties greatly. With the lengthening of holding time, the strength and hardness increase, but the elongation increases first and then decreases, the synthetical mechanical properties are optimal at 4.5～5 hours. The re-aging can homogenize microstructure, the re-aging at 100 ℃×2 h air cooling +155 ℃×4.5 h air cooling can improve the elongation by 170%～300%, and the strength and hardness still keep a high level.