Study on the Cross Section Vickers Hardness Determination Method of Hot Rolled Ribbed Bars in GB/T 1499.2-2018

The Vickers hardness tests were carried out on the unclosed ring around the base circle of the hot rolled ribbed bars of different specifications with different loads. Through the comparison analysis, the problems in the use of the test method specified in the new national standard GB/T 1499.2-2018 for hot rolled ribbed bars were discussed. The results show that when using the test method specified by the standard, cases such as being difficult to obtain reliable results, the test points being insufficient or the test being not carried out, often appear. Meanwhile, it is difficult to locate the edge position, which reduces the test efficiency. It is recommended to select the appropriate loads for the Vickers hardness test according to the actual situation of the outside unclosed loop around the base circle of the sample. Under the premise of meeting the standard requirements, large load is preferred to improve the test accuracy.