Impact of applied loads on wear mechanisms in H13 steel at various preheating temperatures during laser powder bed fusion additive manufacturing

In laser powder bed fusion (LPBF), processed H13 tooling has a broad application prospect in the mold and die industry. In practice, however, it is often impossible to obtain hot wear resistance and compressive residual stresses which constrain its development, affecting hence the wear performance and service life. Under these conditions, substrate preheating is an effective way to reduce thermal stress and defects of H13 for tooling applications. This research paper emphasizes the main characteristics of preheating temperature and its chief induced properties on microstructure and wear behavior of LPBF-processed H13 steel. The elevated preheating temperature altered the microstructure, increasing hardness and wear resistance. Under low applied loads, better wear resistance was attributed to high hardness and tribo-oxide layer formation. Whereas under high applied loads, it was dominated by the increased hardness due to strain hardening.