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

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 R_p0.2, 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.