Selective and diffusion surface hardening treatments: Comparative environmental assessment study

Environmental studies focused on steel surface hardening technologies, particularly laser hardening and nitriding treatments, are notably scarce. Consequently, the environmental impact of steel laser hardening and nitriding treatments requires further investigation to identify measures that can enhance the sustainability of the steel component industry. Within this framework, a Life Cycle Assessment (LCA) study was carried out to evaluate and compare the environmental aspects and potential impacts associated with steel surface hardening through laser hardening (LH), low pressure nitriding (LPN), and plasma nitriding (PN). The results for Global Warming Potential (GWP) and Cumulative Energy Demand (CED) show that, when considering the treated surface area (m 2 ), LH presents the lowest environmental impact among the three technologies for a single m 2 . Nevertheless, the break-even points were determined to be approximately 2.07 m 2 for PN and 2.55 m 2 for LPN. Although LH exhibits greater environmental impact when larger surface areas are treated, it demonstrates superior environmental performance for smaller treated areas.