相变在铁基合金抗空蚀中的作用机理  

Action Mechanism of Phase Transformation on Cavitation Erosion Resistance for Ferrous Alloy

作　　者：王再友[1] 朱金华[2] 

机构地区：[1]南京工程学院材料工程学院,南京211167 [2]西安交通大学金属材料强度国家重点实验室,西安710049

出　　处：《机械工程学报》2008年第3期94-98,共5页Journal of Mechanical Engineering

基　　金：田家自然科学基金(59831030);江苏省自然科学基金(BK2005112);江苏省高校自然科学研究(05KJD430082)资助项目。

摘　　要：采用旋转圆盘试验机以45 m/s对8种奥氏体铁基合金的抗空蚀性能与2种不同晶体结构马氏体铁基合金进行对比研究,通过对组织结构X射线分析和表面局域弹性h_e值的模拟测定,探索相变对抗空蚀性能的影响规律及机理。结果表明,空蚀诱发相变与未诱发相变的奥氏体材料及马氏体材料试验48 h空蚀率都随着局域弹性h_e值增加而降低,局域弹性h_e值是抗空蚀性能的第一控制因素。相变在抗空蚀性能中的作用取决于诱发马氏体的能量吸收及h_e值大小,h_e值相近时空蚀诱发相变吸收能量可提高抗空蚀性能。奥氏体Fe-Mn-Si合金抗空蚀性能因诱发的密排六方ε马氏体具有高的局域弹性h_e值而大大优于诱发体心立方α马氏体的奥氏体Cr-Ni不锈钢。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.

关 键 词：抗空蚀性能 FE-MN-SI合金 不锈钢 相变 表面局域弹性 

分 类 号：TG115[金属学及工艺—物理冶金]