中国物理B ›› 2022, Vol. 31 ›› Issue (11): 116402-116402.doi: 10.1088/1674-1056/ac744a
Pan-Pan Xu(徐攀攀)1, Jin-Yao Ma(马晋遥)1,2,†, Zhou-Hua Jiang(姜周华)4, Yi Zhang(张翊)1, Chao-Xiong Liang(梁超雄)1, Nan Dong(董楠)1, and Pei-De Han(韩培德)1,‡
Pan-Pan Xu(徐攀攀)1, Jin-Yao Ma(马晋遥)1,2,†, Zhou-Hua Jiang(姜周华)4, Yi Zhang(张翊)1, Chao-Xiong Liang(梁超雄)1, Nan Dong(董楠)1, and Pei-De Han(韩培德)1,‡
摘要: Precipitation in super-austenitic stainless steels will significantly affect their corrosion resistance and hot workability. The effects of Cr and Mo on precipitation behaviors were mainly achieved by affecting the driving force for precipitation, especially Mo has a more substantial promotion effect on the formation of the σ phase than Cr. In the present study, B addition to the S31254 super-austenitic stainless steels shows an excellent ability to inhibit precipitation. The effect of B on the precipitation behaviors was investigated by microstructure characterization and theoretical calculations. The experimental observation shows that the small addition of B inhibits the formation of the σ phase along grain boundaries and changes from continuous to intermittent distribution. Moreover, the inhibitory effect increased obviously with the increase of B content. The influence of B addition was theoretically analyzed from the atomic level, and the calculation results demonstrate that B can inhibit the formation of σ phase precipitates by suppressing Mo migration to grain boundaries. It is found that B and Mo are inclined to segregate at Σ 5 and Σ 9 grain boundaries, with B showing the most severe grain boundary segregation tendency. While B distribution at the grain boundary before precipitation begins, the segregation of Mo and Cr will be restrained. Additionally, B's occupation will induce a high potential barrier, making it difficult for Mo to diffuse towards grain boundaries.
中图分类号: (Phase separation and segregation in alloying)