Investigation of wear and corrosion behavior of WAAM fabricated ER70S-6 workpieces

Abstract

This study explores the wear and corrosion behavior of mild steel (ER70S-6) components fabricated using wire arc additive manufacturing (WAAM), with the aim of evaluating their suitability for demanding industrial applications. Despite WAAM's advantages in fabricating medium-to-large metallic structures with favorable mechanical properties, its tribological and electrochemical performance remains underexplored. To address this gap, dry sliding wear tests were conducted on samples extracted from three distinct build regions bottom, middle, and top under applied loads of 15, 20, and 25 N. The middle section exhibited the highest wear at 25 N, while the bottom section showed the least wear at 15 N. Corrosion resistance was assessed through potentiodynamic polarization testing in a 3.5% NaCl solution, revealing the highest corrosion rate in the middle region (0.160 mm/year), followed by the top (0.144 mm/year) and bottom (0.129 mm/year). These variations are attributed to microstructural differences, particularly grain coarsening and pearlite content across the build height. Despite local variations, the overall mechanical properties including microhardness (176 ± 4 HV) and grain size (8.78 ± 0.13 µm) remained reasonably consistent throughout the build, indicating reliable structural integrity of the WAAM-fabricated components. The findings provide novel insights into the layer-wise performance characteristics of WAAM-fabricated components, extending current knowledge on their behavior in wear- and corrosion-prone environments.