退火工艺对GH4169合金带材组织和力学性能的影响

为解决GH4169合金带材国产化制备工艺不成熟导致的组织及性能控制不稳定问题,对厚度为0.4 mm的GH4169合金带材的热处理工艺进行研究。讨论了不同退火温度、不同保温时间对带材金相组织、力学性能的影响,结果表明,退火温度对带材显微组织和力学性能存在显著影响,随着退火温度的提高,合金带材晶粒尺寸增大,同时合金抗拉强度、屈服强度和硬度呈下降趋势,而伸长率呈升高趋势;适当缩短保温时间可以使晶粒尺寸均匀,并起到细化晶粒的作用,与此同时,合金力学性能表现出抗拉强度、屈服强度和硬度增大,同时伸长率呈下降趋势。综合分析组织及性能,0.4 mm的GH4169合金带材最佳退火工艺为退火温度1 050 ℃、保温时间1.5 min,在该工艺下带材的晶粒度为8.5级,抗拉强度为870.5 MPa,屈服强度为389.5 MPa,伸长率为51.5%,维氏硬度为204HV1。

Effect of annealing process on microstructure and mechanical properties of GH4169 alloy strip

In order to solve the problem of unstable microstructure and property control caused by the immature domestic preparation process of GH4169 alloy strip, the heat treatment process of GH4169 alloy strip with a thickness of 0.4 mm was studied. The effects of different annealing temperatures and different holding times on the metallographic structure and mechanical properties of the strip were disscussed. The results show that the annealing temperature has significant effect on the microstructure and mechanical properties of the alloy strip. With the increase of annealing temperature, the grain size of alloy strip increases, while the tensile strength, yield strength and hardness of the alloy decrease, and the elongation increases. Appropriately shortening the holding time can make the grain size uniform, and play the role in refining the grain. At the same time, the mechanical properties of the alloy show an increasing trend in tensile strength, yield strength and hardness, and a decreasing trend in elongation. Comprehensive analysis of the microstructure and properties shows that the optimal annealing process for the 0.4 mm GH4169 alloy strip is annealing temperature of 1 050 ℃ and holding time of 1.5 min. Under this process, the grain size of the strip is grade 8.5, the tensile strength is 870.5 MPa, the yield strength is 389.5 MPa, the elongation is 51.5%, and the Vickers hardness is 204HV1.