变形条件对GH169合金的流动应力和显微组织的影响

 根据热加工模拟试验,GH169合金高温下的流动应力值比合金结构钢高得多,而且加工硬化明显。变形条件对其流动应力和显微组织有较大影响。在一定条件下,即使变形温度较高,也可获得细晶组织,变形后采用迅速冷却可细化晶粒。对于GH169合金可通过形变热处理有效地控制其显微组织。

THE INFLUENCE OF DEFORMATION CONDITIONS ON THE FLOW STRESS AND MICROSTRUCTURE OF AIIOY GH169

In this paper the dependence of flow stress in alloy GH169 on the deformation temperature, strain and strain rate based on the data of hot working simulation test was defined for the first time. Experimental results indicate that for the alloy GH169 the values of flow stress at high temperatures are much higher than that of alloy steel and the work hardening is remarkable. The deformation conditions have significant influence on the flow stress and microstructure of alloy GH169. It was found that under certain conditions fine grain structure can be obtained even though the deformation processes were carried out at high temperatures. This finding is beneficial to the raise of productivity of forming processes. Increasing the cooling rate after deformation is also favourable to the development of fine grain structure. To osum up, the microstructure of alloy GH169 can be controlled effectively through thermomechanical treatment.