SUS304奥氏体不锈钢的摩擦变形层研究

Friction-induced Deformation Layer of SUS 304 Austenitic Stainless Steel

研究了SUS 304奥氏体不锈钢与Al2O3陶瓷球以及GCr15轴承钢球对摩的摩擦特性,利用X射线衍射仪、金相显微镜和显微硬度计研究了SUS 304奥氏体不锈钢磨痕表层及其次表层硬度、磨痕表面的马氏体转变与试验条件的关系.结果表明:当载荷大于30 N后,摩擦系数在剧烈波动前存在1个与试验时间或滑动距离相关的孕育期;SUS 304奥氏体不锈钢磨痕表层的显微硬度从次表层至表层呈上升趋势;在相同滑动速度下,随着载荷增加,磨痕表层的显微硬度增大;摩擦诱发了亚稳奥氏体向马氏体转变,且磨痕表层诱发转变的马氏体含量随载荷和滑动速度的增加而降低;在载荷和摩擦剪切应力作用下,由于表层晶粒细化、相变马氏体和高密度位错的综合作用使得其显微硬度增大.

Microhardness on the surface and sub-surface, the martensitic transformation on the wear trace were investigated after the friction tests of SUS 304 austenitic stainless steel at different conditions using Ball-on-Disc test method. X-ray diffraction, optical micrograph and microhardness measurement techniques were employed in the present paper. The microhardness of the materials under the wear traces increased with pressure but it decreased when the distance to the surface increased. The friction-induced transformation of austenite to martensite on the worn surface was observed, and the amount of friction-induced martensite decreased when the pressure and the slid- ing speed increased. The increasement of hardness in the friction layer was due to the integrating actions of fined grain, transformed martensite and a high density of dislocations.