The objective of 4th International Conference and Expo on Heat Treatment and Surface Engineering, HT&SE 2023 is to bring together industry professionals, senior executives, managers, engineers and researchers, heat treatment professionals, tool makers and users, suppliers of heat treatment and surface engineering plant and equipment, as well as academicians from and all over the world. The Conference and exhibition are aimed to create an opportunity for display and exchange of technical information and updates at an international level among the specialists involved in heat treatment and surface engineering.