Effect of surface work hardening on wear behavior of Hadfield steel

Shot peening has become an effective method to strengthen alloy. In this investigation, it has been used to work-harden Hadfield steel. It has been regarded that the surface hardness of Hadfield steel has been increased greatly after shot peening. Using electron scanning microscope (SEM), high resolution transmission electron microscope (HRTEM) and X-ray diffraction (XRD) analysis, the microstructure of shot penned surface layer was examined. It has been observed that a nanocrystalline surface layer is formed. The grain sizes of surface were decreased to 11.1–17.4 nm and the maximum hardened layer can reach to 100 μm after the treatment. Surface hardness was also increased with increasing shot peening period. Two-body and three-body abrasive wear experiments were carried out for work hardening and original specimens, separately. The results showed that the three-body wear resistance of the nanocrystallized Hadfield steel has distinctly been improved using soft abrasive particles. For harder abrasive particles like emery paper, the increased hardness and grain refinement by shot peening cannot improve two-body abrasive wear resistance.