DZ125镍基高温合金高温持久断裂后的位错组态  

DISLOCATION CONFIGURATION IN DZ125 Ni-BASED SUPERALLOY AFTER HIGH TEMPERATURE STRESS RUPTURE

作　　者：丁智[1] 张军[1] 王常帅[1] 苏海军[1] 刘林[1] 傅恒志[1] 

机构地区：[1]西北工业大学凝固技术国家重点实验室,西安710072

出　　处：《金属学报》2011年第1期47-52,共6页Acta Metallurgica Sinica

基　　金：国家自然科学基金项目50931004和50827102;国家重点基础研究发展计划项目2010CB631202和2011CB610406;国家高技术研究发展计划项目2007AA03Z552资助~~

摘　　要：研究了熔体超温处理工艺对DZ125镍基高温合金铸态及热处理态高温持久试样位错组态的影响.结果表明:铸态试样的高温持久寿命随熔体超温处理温度的升高而增加.热处理态试样的高温持久寿命随超温处理温度的升高表现为先增加后减少,当超温处理温度为1650℃时,持久寿命达到最大值.随熔体超温处理温度的升高,铸态试样位错密度增大且位错多呈波浪形和不规则网络状分布,热处理态试样中出现规则的多边形位错网,有利于持久性能的提高.位错网中位错的Burgers矢量为a/2〈110〉和a〈100〉.高温持久变形机制为位错的切割或攀移.随超温处理温度的升高,切入γ′相的位错数量减少,并且有位错列和位错对列攀移通过γ′相.The influence of the melt superheating treatment on the dislocation configuration in the as-cast and heat-treated samples of DZ125 Ni-based superalloy after high temperature stress rupture is studied. The results show that with the increase of the melt superheating temperature, the stress rupture life of the as-cast sample is increased and that of the heat-treated sample is first increased and then reduced. When the superheating temperature is 1650℃, the stress rupture life of the heat-treated sample reaches the maximum. With the increase of the melt superheating temperature, the dislocation density is increased and the waved or irregular dislocation networks appear in the as-cast sample, while the regular polygonal dislocation networks appear in the heat-treated sample, which is helpful to elevate the stress rupture property. The Burgers vectors of dislocations in the network are respectively a/2110 and a100. The high temperature stress rupture deformation mechanism is mainly shearing and climbing of dislocation. It is demonstrated that there are few dislocations shearing theγ＇ phase and there are dislocation arrays or pairs climbing over theγ＇ phase.

关 键 词：熔体超温处理 高温持久寿命 位错组态 镍基高温合金 

分 类 号：TF777.1[冶金工程—钢铁冶金]