Grain boundary co-segregation of B and Ce hindering the precipitates of S31254 super austenitic stainless steel
Jiemin Gao, Jinyao Ma, Song Yang, Zhensen Guo, Jie Ma, Huabing Li, Zhouhua Jiang, Peide Han
Abstract
The influence of boron (B) and cerium (Ce) grain boundary (GB) co-segregation on the precipitates formation of S31254 during 950–1050 °C was studied through a new heat treatment process. The results show that B and Ce segregate at GBs by air cooling and diffusion at 300 °C. The segregation of B and Ce at GBs inhibits formation of σ phases. B can dissolve in precipitates, which leads to the serrated GBs. Ce can't dissolve in precipitates, which makes the distribution of the precipitates more discontinuous. There is still nano-scale precipitates with the addition of B and Ce after aging for 180 min at 1050 °C. B and Ce at GBs promote mechanical properties of S31254.