拉伸试验的验证比对与延塑性指标能力分析

文章介绍了在宝钢股份有限公司所开展的有关拉伸试验能力的实验室间比对验证工作。比对验证工作选用的是目前主流配置的Zwick,Instron等试验机及其各自的电子引伸计测量系统,通过R_(p0．2),R_m,A_(80mm),A_g,n值与r值反映试验机对冷轧薄板强塑性能指标的测试能力。相对标准偏差RSD反映出对于指标的测量精密度与重现性由高至低依次为n值,R_m,A_g,A_(80mm)(手工),A_(80mm)(自动),r值与R_(p0．2)。并简要分析了各指标的测量原理及其测量偏差与试验机软硬件功能设置的影响关系。此外,为消除采用现行方法测量r值时受宽度测量偏差造成的影响,文章介绍了一种应变区间范围内拟合求解r值的新方法。

Interlaboratory round robin comparison of tensile testing and the proficiency analysis of plastic indexes

An interlaboratory round robin comparison testing of tensile had been performed in Baoshan Iron & Steel Co.,Ltd. Series of strength and plasticity indexes including R_(p0.2),R_m,A_(80mm),n value and r value obtained by Zwick,Instron testing machines with respective extensometers were analyzed statistically for the proficiency assessment.Based on the concept of Rela- tive Standard Deviation.i.e.RSD,the best precision of the measurement for the reproducibility of a given index was n value, with R_m,A_g,A_(80mm)(manually),A_(80mm)(extensometer),r value and R_(p0.2)as followed in sequence.The measurement princi- pies and models of indexes were briefly introduced in the paper,revealing the influence of hardware functionality and software set tings on the deviation of measurement results.In addition,a new method for the regression of plastic strain ratio,r value rela- tive to a strain range was proposed to overcome the scatter of r value results by common method,which is observed strongly caused by the fluctuation of width monitoring.