摘要
为了考察热处理工艺对成分偏析及持久性能的影响,通过不同条件的热处理及微区成分分析,研究了固溶温度对合金中枝晶臂/枝晶间区域难熔元素偏析的影响.根据DSC曲线分析、组织形貌观察及持久性能测试,研究了热处理工艺对合金持久性能的影响.结果表明:铸态合金中元素Cr、Co、Mo、Re富集于枝晶干,元素Al、Ta、W等富集于枝晶间,经高温固溶处理可明显降低难熔元素在枝晶臂/间的偏析程度.根据DSC曲线确定出合金的初熔温度为1325℃,并制定出合金的热处理工艺.经较低温度固溶处理,合金中难熔元素的偏析程度较大,形成的筏状γ′相与应力轴方向成45°角,合金具有较短的持久寿命;而经1320℃高温固溶处理,元素的偏析程度减小,可较大幅度地提高合金的持久寿命.
In order to identify the effect of heat treatment on both composition segregation and enduring properties, the influence of solution temperature on the segregation degree of refractory elements in the dendritic and interdendritic areas was investigated by means of the micro-area composition analysis. Furthermore, the influence of heat treatment technology on the enduring properties of a single crystal nickel：based superalloy was also studied through performing the DSC analysis, microstructural observation and enduring properties measnrement. The results show that the initial melting temperature of the alloy is 1 325 ℃, and the heat treatment technology is determined according to the DSC analysis. For as-cast superalloy, such elements as Cr, Co, Mo and Re are richer in the dendritic area, while those elements including Al, Ta and W are segregated to the interdendritic area. When the solution temperature is lower, the more serious segregation of the refractory elements appears, which reduces the enduring lifetime of the alloy. However, the segregation degree of the refractory elements may be obviously decreased by solution treatment at 1 320 ℃, which may considerably enhance the enduring lifetimes of the alloy.
出处
《沈阳工业大学学报》
EI
CAS
2009年第5期525-530,共6页
Journal of Shenyang University of Technology
基金
国家自然科学基金资助项目(50571070)
关键词
单晶
镍基合金
元素偏析
差热曲线
热处理制度
组织结构
TCP相
持久寿命
single crystal
Ni-based superalloy
element segregation
DSC analysis
heat treatment
microstructure
topologically closed-packed phase
enduring lifetime
