汽车发动机用高温合金丝材的研制

Decelopment of Superalloy Wires for Automobile Engines

研究了冷拉变形量、固溶热处理制度和时效热处理制度对汽车发动机阀门用NCF751合金冷拉丝材的晶粒度和力学性能的影响。研究结果表明,NCF751合金经过25%左右的冷拉变形量之后,可获得均匀细小的晶粒组织和良好的综合性能;随着固溶温度的提高,合金的晶粒度呈现增大的趋势,硬度变化较大;随着固溶时间的延长,合金的晶粒度更均匀,硬度变化较小;随着时效温度的提高,合金的室温拉伸强度和硬度先增大后减小;时效时间的延长对合金的室温拉伸强度和硬度的影响较小,基本保持不变。

Effect of cold-drawing deformation, solution treatment and ageing treatment on the grain size and mechanical properties of Ni-based superalloy NCF751 wires for automobile engines was studied. The result indicates that a uniform and fine grain structure and desirable mechanical properties of the alloy were obtained after a 25% of cold-drawing deformation. It was shown that with a rise in solution treatment temperature, the alloy's grain size increased and its hardness varied a lot. With the elongation of solution treatment, the alloy's grain size became more uniform while hardness nearly remained unchanged. With a rise in ageing temperature, the alloy's room temperature tensile strength and hardness increased and then decreased. The time of ageing treatment was revealed to have little effect on the alloy's room temperature tensile strength and hardness.