Improving Mechanical Properties of M50 Steel via Martensite Transformation and Carbide Precipitation Under Electromagnetic Shock Treatment

As a new type of material post‐treatment method, electromagnetic shock treatment (EMST) shows the advantages of high‐energy utilization rate, short time consumption, and the ability to perform local treatment. This treatment method can provide new technologies and theoretical guidance for the high‐performance manufacturing of bearings and can be used to regulate the microstructure and mechanical properties of bearings. In this article, the tempered M50 steel (8Cr4Mo4V) is selected as the research object to explore the influence mechanism of EMST on its microstructure (grain size, grain orientation, texture, dislocation density) and mechanical properties (hardness, compressive strength). Microstructure observation results show that the original austenite grain boundaries became blurred after EMST. The acicular martensite is formed, accompanied by the precipitation of lath carbides and short‐rod carbides. The average KAM values decrease from 0.95° to 0.67° after EMST. The results of mechanical tests show that the hardness of the sample after EMST increases from 316.7 to 333.8 HV, and the compressive yield strength increases from 1611 to 1899 MPa. These findings indicate that EMST has the potential to manipulate the microstructure of high‐strength steel and improve its mechanical properties.