Effects of applying electroshocking treatment at different stages of cold rolling-quenching-tempering process on microstructure and properties of M50 steel

• EST integrated into cold rolling-quenching-tempering significantly refines grain size (average reduction 10.1%) and reduces dislocation density (average reduction 20.9%). • EST promotes carbide dissolution and more uniform distribution along grain boundaries, contributing to enhanced mechanical properties. • The rolling-quenching-tempering-EST sequence yields excellent overall performance: hardness +1.4%, tensile strength +17.7%, and elongation at break +24.3%. • The rolling-EST-quenching-tempering sequence achieves the best tensile performance, with tensile strength +30.0% and elongation at break +30.7%.