Influence of Magnetostrictive Effects on Hardness and Thermal Stress During Laser Cladding of SDSS 2507 on SS 420 Under the Steady Magnetic Field

Abstract Achieving high hardness and exceptional wear resistance in the laser-clad layer has been the focus of surface engineering research. This study investigates laser cladding of SDSS 2507 onto SS 420 under steady magnetic fields (SMF) to analyze magnetostriction’s effects on hardness and thermal stress. Three experiments (0 mT, 3 mT, and 6 mT SMF) revealed that magnetostriction reduces elastic modulus (E) while retaining high hardness (H), improving wear resistance (H/E) and resistance to plastic deformation (H3/E2). Under 6 mT SMF, wear resistance increased by 20.45% compared to 0 mT, while thermal stress was released by 0.16 GPa. The microstructural analysis demonstrated SMF’s influence on refined grain structures and uniform elemental distribution, with retained austenite/ferrite dual-phase balance critical for hardness. High H/E and H3/E2 ratios were achieved by decreasing elastic modulus (E) via magnetostriction, directly enhancing wear resistance and resistance to plastic deformation. These results validate a novel strategy to combat cracking and wear in SS 420 injection molding dies: reduced thermal stress preserves dimensional accuracy, whereas increased hardness mitigates surface wear from repetitive contact. This work advances magnetic field-assisted laser cladding by linking magnetostriction to mechanical property optimization, offering a scalable solution for precision tooling applications.