Experimental and statistical investigation of the impact of laser process parameters on the mechanical properties of H13 tool steel bulk

This study investigates the effect of laser treatment parameters on the tensile behavior of H13 tool steel in both quenched and tempered conditions. The effects of varying laser parameters on ultimate tensile strength and elongation at fracture which is the aim of this research were explored by employing a bionic unit to apply laser treatment with two parallel lines on the steel surface. These parameters are crucial for understanding material performance under tensile stress. Statistical analysis, including an analysis of variance (ANOVA), and fractographic analysis using SEM were conducted to analyze the results. The findings reveal a significant enhancement in the ultimate tensile strength of the laser-treated samples, with values ranging between 1342.27 and 1497.25 MPa, surpassing the non-treated substrate's strength of 1247.23 MPa. However, a decrease in elongation at fracture was observed, indicating increased brittleness post-laser treatment, with elongation values notably lower than the non-treated sample's 14.71%. The hardness values within the laser-treated zone exhibited a high variance, with the highest values found in the hardened zone ranging from 65.7 to 61.4 HRC, suggesting the formation of fine carbides and lath martensite due to rapid cooling and martensitic transformation. Furthermore, the depth of the laser-transformed zone, significantly influenced by laser power, varied between 1.30 and 1.9 mm, highlighting the critical role of laser parameters in affecting material properties. The study highlights a critical balance between ductility and strength in laser-treated H13 tool steel, which is essential for optimizing the material's performance for industrial applications.