Influence Factors and Relative Deviation of Conversion of Building Structure Steel Strength by Leeb Hardness

The differences of results of Leeb hardness converted into tensile strength of building structure steel in three standards, such as GB/T 50344—2019, were compared, the reasons for the differences were discussed based on theoretical analysis and experimental research, and the conversion relationship between hardness and strength of steel for building steel structure was studied. Through regression analysis, the conversion formula and relative deviation of conversion of strength by Leeb hardness were given and compared with the standard conversion value. The results show that due to the different processing and fixation methods of samples, the results of conversion of building structure steel tensile strength by Leeb hardness in the three standards are quite different. In the engineering field test, if the appropriate support or coupling is not carried out, the test results of different positions of the same steel plate will have obvious differences, and the thinner the steel plate is, the greater the difference is. There is a positive correlation between the Leeb hardness and strength of steel plate when the coupling method is used for the test of the hardness of steel plate, and the relative deviation of conversion value can basically meet the requirements of field engineering testing, which can be applied to engineering practice.