熔体过热处理温度对铸态镍基高温合金K417返回料组织和力学性能的影响

Effect of Temperature of Melt Superheat Treatment on Microstructure and Mechanical Properties of Recycled Ni-Base Superalloy K417

摘要:

用金相显微镜和扫描电镜研究了镍基高温合金K417返回料在1530, 1650, 1700, 1800 ℃下进行5 min熔体处理后显微组织以及碳化物尺寸、分布和形态的变化，并研究了熔体过热处理后组织变化对合金室温拉伸性能和高温拉伸性能的影响。结果表明，在相同铸造条件下，熔体高温处理能使碳化物由块状向骨架状转变并有效阻止裂纹的扩展，从而使合金得到良好的室温和高温强度及塑性

Abstract:

Microstructure evolution of recycled nickel-base superalloy K417 after melt superheat treatment at different temperatures of 1530, 1650, 1700 and 1800 oC for 5 min were investigated using optical microscope (OM) and scanning electronic microscope (SEM). The size, distribution and morphology of carbides were studied. The effect of microstructure change after melt superheat treatment on tensile properties at room and elevated temperatures was analyzed. Results show that the propagation of cracks is prevented effectively due to the morphology changes of carbides from block to script during the melt high temperature treatment, which results in higher strength and ductility of K417 alloy at room and elevated temperatures