镍基Nimonic105合金的热处理工艺优化

Optimization of heat treatment process of nickel-based superalloy Nimonic105

研究了Nimonic105镍基合金的热处理工艺对合金室、高温力学性能的影响,发现只采用固溶处理(单固溶或双固溶)可有效提升Nimonic105合金的室温冲击韧性,且固溶处理后,冷速越快对合金韧性的提升越大。本文推荐Nimonic105合金的优化热处理工艺为1150℃×4 h,水冷+1065℃×2 h,水冷。结合力学性能和相分析结果可知,Nimonic105合金的γ'相可提高室、高温屈服强度;M23C6相仅能提高Nimonic105合金的高温抗拉强度和高温塑性,对Nimonic105合金的室温抗拉强度和室、高温屈服强度的影响不大,而且晶界大量析出的M23C6相是Nimonic105合金冲击韧性下降的主要原因。只进行双固溶处理后可获得12%的γ'相和2.5%的M23C6相,使得Nimonic105合金具有较好的室、高温强度和塑性,同时保证了其冲击韧性仍处于较高的水平。

Effect of heat treatment process on mechanical properties of Nimonic105 alloy at both room and high temperature was studied.The results show that solution treatment（single or double solute solution） can effectively enhance the impact toughness of the Nimonic105 alloy at room temperature,and after the solution treatment,the toughness of the alloy increases with increasing cooling rate.The optimal heat treatment process of the Nimonic105 alloy is heat treated at 1150 ℃ for 4 h by water cooling,and then heat treated at 1065 ℃ for 2h by water cooling.Mechanical properties and phase analysis results show that γ＇ phase can improve the yield strength of the Nimonic105 alloy at both room and high temperature,while M23C6 phase can improve the high-temperature tensile strength and high temperature plasticity,and M23C6 phase has little effect on the tensile strength at room temperature and yield strength at both room and high temperature.The main reason of the decline of impact toughness is large number of M23C6 phase precipitated in the grain boundary.After the double solution treatment,it has precipitated 12% of γ ＇phase and 2.5% of M23C6 phase that make sure Nimonic105 alloy has good strength and plasticity at both room and high temperature,and ensure its impact toughness is still at a high level.