新型钴基高温合金成分设计及其组织与性能

Composition Design of a New Cobalt Base Superalloy and Its Microstructure and Properties

设计了新型钴基高温合金的成分,并对新合金的组织及性能进行了研究.结果表明:钨作为合金的主要固溶元素,其质量分数必须控制在17.0%～18.5%的范围内,才能有效地起到固溶强化作用,过多的钨元素将与钴、碳、铬、镍等元素形成大量的μ和M6C等析出相,晶粒也因此而细化,虽然合金的室温强度会有所提高,但在1200℃的高温下变得较为薄弱的大量晶界使强度明显降低.

A new cobalt base superalloy was developed. As a main solution strengthening element of this alloy, the content of W must be controlled within 17. 0%-18.5 % for strengthen the alloy efficiently. Excessive W element would be combined with Co, C, Cr and Ni to form μ and M4C precipitates and thus to refine the grains. Although the alloy with higher W content had higher room-temperature tensile strength, but the tensile strength of the alloy with refined grains would be dramatically reduced at 1 200 ℃ because grain boundaries were weaker at such high temperature.