高温时效对K447A合金显微组织及力学性能的影响

Effects of High Temperature Aging on Microstructure and Mechanical Properties of K447A Superalloy

为增大K447A合金中γ′相尺寸以及体积分数,并使碳化物均匀分布,在热处理过程中加入高温时效处理,研究了高温时效对K447A合金显微组织及性能的影响。结果表明,经过高温时效的K447A合金晶粒内及晶界上碳化物周围形成一层γ′相,能减缓裂缝沿碳化物界面破裂及生长的速率。高温时效处理可以有效提高合金的中温、高温持久寿命及伸长率。

In order to increase the size and volume fraction ofγ′phase in K447A alloy and make carbides distribute uniformly,the effect of high temperature aging on the microstructure and properties of K447A alloy was studied.The results show that a layer ofγ'phase is formed in the grains and around the carbides on the grain boundary of K447A alloy after high temperature aging,which can slow down the fracture and growth rate of cracks along the carbide interface.High temperature aging treatment can effectively improve the rupture life and elongation of the alloy at medium and high temperatures.