轧后冷却和固溶处理对IN718合金组织和性能的影响

Influence of cooling and solution treatment on microstructure and mechanical property of hot rolled IN718 alloy

IN718合金作为航空、航天、核能、石油领域大量应用的关键材料,其晶粒尺寸与δ相分布会严重影响产品最终性能。在该合金热轧结束后采用轧后空冷＋离线固溶、轧后水冷＋离线固溶、轧后在线固溶3种冷却和固溶处理工艺,观察晶粒大小与δ相的析出情况以及力学性能测试。结果表明,在3种工艺下δ相在晶界上均呈不连续的颗粒状或短棒状分布,但在线固溶处理后材料的晶粒尺寸与δ相析出数量适中,高温持久性能较水冷＋固溶工艺提高了26%,室温和高温下的伸长率较空冷＋固溶工艺分别提高了17%和6%,综合力学性能优异,是最佳的轧后处理方式。

IN718 alloy is widely used as parts in fields of aviation,aerospace,nuclear power and petrochemical industries,the performance of final product is related to grain size and δ phase distribution. Three cooling and solution treatment processes were used after the hot-rolling,and the grain size,the δ phase distribution and the related mechanical properties of the final products were analyzed as well. It is shown that the similar δ phase is precipitated on grain boundaries in granular or short-bar manner have been obtained in different processes,the proper grain size and the moderate amount of δ phase precipitation,even the excellent comprehensive mechanical properties can be obtained after online solution treatment.