Structure and Property Modulations of 13Cr Stainless Steel Through Microgravity Solidification and Minor Ce Addition

Both rare-earth doping and microgravity solidification processing bring significant influences upon the structure formation and mechanical properties of various alloys. Herein, the microstructure and performance of 13Cr martensitic stainless steel are modulated by adding minor Ce content and microgravity solidification by means of drop tube technique. The lattice structure of constituent phase α(Fe) is deformed evidently by microgravity solidification, and the lattice parameter variation is 1.8 times of that caused by Ce addition. The microstructures of this steel processed by arc melting consist of lath-shaped martensites and a few feather-shaped bainites whose volume fraction increases with the Ce content. The bainite is replaced by ferrite in the rapidly solidified microstructure of 13Cr steel under microgravity condition. Although both microgravity solidification and Ce addition induce the microstructure refinement and inclusion spheroidization, the former effect plays the dominant role. The compressive properties and microhardness decrease moderately with Ce addition due to the slight increase in bainite, however, the microgravity solidification brought the hardening effect and thus the microhardness of the steel droplets increases with undercooling.