热镀锌薄板规定塑性延伸强度测定的影响因素

Influence Factors on Measurement of Specified Plastic Elongation Strength for Hot-Dip Galvanized Sheets

针对两个试验室测定热镀锌薄板规定塑性延伸强度存在差异的情况,讨论了拉伸应变测量方式、试样夹持状态、原始横截面积测量等因素对规定塑性延伸强度测定结果的影响。结果表明:试验室A直接以横梁位移来代替试样的变形量,这与Rp0.2的测定原理不符,导致出现测定结果比真实值低的情况;彩涂后试样的规定塑性延伸强度较未彩涂试样的偏低,主要原因是彩涂试样夹持段打滑;在试样实际厚度呈负公差的情况下,以名义尺寸输入试样的原始横截面积尺寸,使得强度值较实测尺寸的偏低。

In view of the differences between the two laboratories for testing the specified plastic elongation strength of the hot-dip galvanized sheet,the effects of measurement method of tensile strain,clamping state of sample and measurement of original cross section area on the measurement results of specified plastic elongation strength were discussed.The results show that the deformation of the sample was replaced directly by the beam displacement in the laboratory A,which was not in conformity with the test principle of Rp0.2,caused the measurement results to be lower than the true value.The specified plastic elongation strength of the samples after color coating were lower than that of the non-coated samples,mainly due to the slipping of the clamp section of the color coating samples.In the case of the negative tolerance of the actual thickness of the samples,the original cross section area of the samples were input in nominal size,so that the strength value was lower than the measured size.