固溶冷却速率对镍基高温合金K444组织和力学性能的影响  

Effects of solution cooling rate on microstructure and mechanical properties of nickel base superalloy K444

作　　者：彭志江[1] 乐献刚[1] 张明俊[1] 侯介山[2] 周兰章[2] 

机构地区：[1]沈阳黎明航空发动机(集团)有限责任公司技术中心,辽宁沈阳110043 [2]中国科学院金属研究所,辽宁沈阳110016

出　　处：《金属热处理》2015年第2期163-168,共6页Heat Treatment of Metals

摘　　要：研究了固溶冷却速率对K444合金显微组织和力学性能的影响。结果表明,控制K444合金固溶后的冷却速度,可获得不同尺寸和形状且呈双态弥散分布的γ'相;较快的固溶冷却速度可使合金中碳化物细化;冷速越大,γ'相尺寸越小,合金拉伸性能及持久寿命越好。合金经1170℃×4 h固溶后,以80℃/min冷速冷却到900℃,再经1050℃×4 h高温时效和850℃×16 h低温时效,可以获得较好的综合性能。Effects of cooling rate after solution treatment on microstructure and mechanical properties of superalloy K444 were investigated. The results show that the binary dispersedly distributed γ＇ precipitates with different size and morphology of the tested alloy can be achieved by controlling the cooling rate after solution treatment. The carbides can be refined by relatively fast cooling rate. Moreover, the higher the cooling rate, the smaller the size of γ＇ precipitates is, and the better the tensile properties and stress-rupture life are. Preferable comprehensive properties can be achieved after solution treatment at 1170 ℃ for 4 h, cooling down to 900 ℃ with cooling rate of 80 ℃/min, and then aged at 1050 ℃ for4 h and dropped down to room temperature by air cooling, followed by low temperature aging at 850 ℃ for 16 h with air cooling to room temperature.

关 键 词：K444合金 固溶 冷却速率 组织 力学性能 

分 类 号：TG162.83[金属学及工艺—热处理]