Application of Micro-magnetic Testing Technology in Yield/Tensile Strength Testing of Cr12MoV Steel and 3Cr13 Steel

Nondestructive and quantitative evaluation of yield strength (R_p0.2) and tensile strength (R_m) of Cr12MoV steel and 3Cr13 steel were investigated based on micro-magnetic method. Firstly, quenching followed by tempering process was performed to change the tensile mechanical properties of specimens. Secondly, the micro-magnetic feature parameters and the yield/tensile strength of the two kinds of carbon steels were measured successively. Afterwards, Grabbs criterion and ReliefF correlation analysis was eliminated the system error and obtained the micro-magnetic characteristics that were sensitive to the yield/tensile strength. Finally, the BP neural network prediction models were established by optimizing the neural network model, which could realize quantitative characterization of yield strength and tensile strength of Cr12MoV steel and 3Cr13 steel. The findings show that micro-magnetic testing method can be used for nondestructive quantitative prediction of yield strength and tensile strength of Cr12MoV steel and 3Cr13 steel. The average errors of the models in predicting the yield strength and tensile strength were less than 3% and 5%, respectively. The proposed research methods and conclusions can provide a reference for the micro-magnetic nondestructive testing of the yield strength and tensile strength of ferromagnetic materials.