Effect of laser surface hardening on the microstructure, hardness and residual stresses of austempered ductile iron grades

► Nd:YAG laser surface hardening of low-medium and upper austempered ductile irons. ► Few differences on the microstructure, case depth and residual stresses of the grades. ► Coarse martensite, retained austenite structures with the graphite nodules unaltered. ► Compressive residual stresses bound to microstructural and microhardness changes. ► Laser hardening improves wear resistance and mechanical properties of ADI grades.