固溶处理对含Gd不锈钢第二相与硬度的影响

Effect of solid solution treatment on secondary phase and hardness of Gd containing stainless steel

研究了不同固溶处理温度对含Gd不锈钢第二相与硬度的影响。结果表明,含Gd不锈钢在1000~1150℃固溶处理30 min后,沿晶界析出的连续第二相只发生部分熔断,大量第二相弥散分布于基体中,由“灰色”相包裹着“亮白色”相,“灰色”相元素组成及含量相对稳定。在1000~1070℃保温30 min固溶处理后,“亮白色”相的Ni几乎完全溶解,Gd浓缩富集,尺寸缩小,“灰色”相长大缓慢,部分“灰色”相形貌变为短棒状。固溶温度升高至1150℃,“亮白色”相中Ni溶解的同时Gd发生扩散及微量溶解,大部分“亮白色”相消失,“灰色”相发生粗化、球化。固溶处理后合金硬度均低于固溶处理前,随着固溶温度的升高,合金硬度呈上升趋势。

The effect of different solid solution treatment temperatures on secondary phase and hardness of the Gd containing stainless steel was studied. The results show that after solid solution treated in the range of 1000-1150 ℃ for 30 min, the continuous secondary phase precipitated along the grain boundary only partially melts, a large number of secondary phases are dispersed in the matrix, and the “bright white” phase is wrapped by the “gray” phase. The element composition and content of “gray” phase are relatively stable. After the solid solution treatment at 1000-1070 ℃ for 30 min, almost all the Ni of the “bright white” phase is dissolved, Gd is concentrated and enriched, its size is reduced, the “gray” phase grows large and slow, and some of the “gray” phase changes to short rod shape. When the solid solution temperature rises to 1150 ℃,while Ni dissolves in the “bright white” phase, Gd diffuses and slightly dissolves, most of the “bright white” phase disappears, the “gray” phase coarsens and spheroids. The hardness of the alloy after solid solution treatment is lower than that before solid solution treatment. With the increase of solid solution temperature, the hardness of the alloy increases.