Supply Chain Environmental Burdens in Stainless Steel Electric Arc Furnace Steelmaking: A Life Cycle Perspective

Electric Arc Furnace (EAF) steelmaking is considered less carbon-intensive than primary production routes; however, stainless-steel production involves significant upstream emissions, critical for comprehensive environmental assessment. This study presents a cradle-to-gate Life Cycle Assessment (LCA) of an EAF steelworks producing stainless steel, based on primary data, conducted according to ISO 14044:2006 and the Environmental Footprint 3.1 method. The analysis shows that raw material consumption represents the main environmental burden (>90% of Single Score) for the five steel families analyzed (i.e., austenitic, ferritic, martensitic, duplex, and precipitation hardening), revealing substantial heterogeneity due to the steel grade final chemical composition, as high alloying generally leads to higher environmental impact. Scrap mix plays a central role in defining the alloying baseline, thus limiting the chemical gap which must be filled by ferroalloy addition. Duplex steel grades exhibit an environmental intensity (2079.66 mPt/ton) four times higher than ferritic and martensitic ones (459.57 and 447.90 mPt/ton), while precipitation hardening and austenitic grades (857.10 and 649.26 mPt/ton) represent an intermediate scenario. A critical divergence emerges between indicators: while the product carbon footprint is dominated by Cr and Ni carbon intensities, the Single Score is driven by Mo resource depletion. These findings demonstrate that steel grade heavily impacts product environmental intensity and that defossilization strategies focusing solely on Cr and Ni supply chains risk overlooking Mo. Consequently, achieving meaningful sustainability requires a multicriteria approach that integrates different environmental issues with supply chain management of raw materials, beyond the current defossilization approach.