摘要
为研究304不锈钢超薄板力学性能与试样尺寸、晶粒尺寸的相关性,应用自制的超薄板专用夹具进行拉伸试验,分析超薄板的厚度、晶粒尺寸对材料力学性能的影响。试验结果表明,随着试样厚度减小,材料的屈服强度先减小而后明显增大。这是因为,当试样厚度大于200μm时,表面层效应起主导作用;当试样厚度小于200μm时,应变梯度效应和表面层钝化膜共同作用。同一厚度下,改变试样的晶粒尺寸结果表明,当厚度尺寸和晶粒尺寸的比值小于2时,板料在厚度方向已没有内部晶粒,位错很容易滑移出自由表面,应力-应变曲线显著降低。
In order to investigate the specimen size dependence and grain size dependence on the mechanical properties for SS304 ultrathin sheet metal ,the uniaxial tensile tests were performed by using self‐designed special fixture for ultrathin sheet metal .The influence of ultrathin sheet metal thickness and grain size on the material properties were analyzed .The experiment results showed that with the decreasing of sheet metal thickness ,the material yield strength decreased at first and then increased significantly . Because when the sheet metal thickness was larger than 200μm ,surface layer effect played a dominant role;to the contrary ,be‐cause of the dual action of strain gradient effect and surface passivation membrane ,the yield strength is decreased .What＇s more , the grain size has been changed under the same thickness ,so when sheet metal thickness‐grain size ratio was less than 2 ,the dis‐location was easy to slip out of the free surface and the stress strain curve decreased significantly .
出处
《塑性工程学报》
CAS
CSCD
北大核心
2014年第6期71-74,共4页
Journal of Plasticity Engineering
基金
博士点基金博导类课题资助项目(20133227110013)
关键词
尺度效应
304不锈钢
超薄板专用夹具
拉伸试验
力学性能
size effect
304 stainless steel
special fixture for ultrathin sheets
tensile test
mechanical properties
