不锈钢超薄板力学性能尺度效应对摩擦的影响研究

Influence of mechanical property size effect of ultrathin stainless steel on friction

分别将304不锈钢的超薄板厚度、晶粒尺寸作为单一变量,先后采用单向拉伸以及摩擦磨损试验,研究流动应力-应变关系,以及所表现的尺度效应与摩擦系数之间相关性。结果表明,随着超薄板厚度尺寸减小,或者晶粒尺寸减小,其屈服强度均呈上升趋势,表现出明显的"越小越强"尺度效应现象。表面形貌观察和测量发现,不锈钢超薄板表面缺陷一般为锈蚀、麻点和结疤等,表面粗糙度基本不受试样厚度和晶粒尺寸的影响。综合分析表明,因不锈钢超薄板厚度或晶粒尺寸不同而产生的力学性能尺度效应并未在很大程度上改变摩擦系数。

To investigate the flow stress-strain relationship and the correlation between mechanical property size effect and friction coefficient, uniaxial tensile tests and friction-wear tests were adopted respectively for 304 ultrathin stainless steel with different thickness and grain size. The results show that the yield strength increases with the decrease of ultrathin sheet thickness or grain size, showing obvious size effect of “the smaller, the stronger”. Surface morphology observation and measurement indicate that the surface defects of ultrathin stainless steel usually were rust, hemp points and scars, and the surface roughness is substantially not affected by specimen thickness and grain size. Comprehensive analyses show that the mechanical property size effect due to the difference of the ultrathin stainless steel thickness and grain size has no significant influences on the friction coefficient.