关键词: Fe-Mn-Si合金, 表面局域弹性, 不锈钢, 抗空蚀性能, 相变

Abstract: Cavitation erosion resistance of 8 austenitic ferrous alloys is investigated by comparison with two kinds of martensitic alloys with different crystal-structure at speed 45 m/s using a rotating disc rig. Based on X-ray diffraction examinations of microstructure and simulative measurements of localized surface layer elasticity he for the tested alloy, effect of phase transformation on the resistance of the alloys is analyzed. The results show that 48 h cavitation mass loss rate of both metastable and stable alloys reduces as the value of the elasticity he increases, and the value of he is the first predominant factor characterizing their resistance. The role of phase transformation in the resistance depends on energy absorption and value of he of cavitation-induced martensite, and the resistance can be improved due to energy absorption of cavitation induced martensite as the value of he is close. The resistance of austenitic Fe-Mn-Si alloy is much better than that of metastable austenitic Cr-Ni stainless steel because the value of he of induced hexagonal closed-packed martensite is obviously larger than that of body-centered cubic martensite.

Key words: Cavitation erosion resistance, Fe-Mn-Si alloy, Localized surface layer elasticity, Phase transformation, Stainless steel