Performance of cutting fluids containing volatile corrosion inhibitors in grinding hardened AISI 4340 steel

Developing sustainable cutting fluids remains a challenge for the metalworking industry, where achieving high surface quality is crucial while meeting environmental and occupational safety requirements. This study evaluated the performance of synthetic, non-hazardous, and biodegradable cutting fluids containing a new class of volatile corrosion inhibitors (V-active VCI) during external cylindrical plunge grinding of hardened AISI 4340 steel. The analysis included fluid viscosity, surface roughness parameters, diametrical wheel wear, grinding power, microhardness, costs, and SEM surface characterization. Compared to conventional synthetic fluids, V-active VCI fluids reduced surface roughness by up to 82% and decreased wheel wear by 84% under the most severe conditions. These results demonstrate the potential of V-active VCI fluids to improve surface integrity and process efficiency, providing a sustainable alternative for precision grinding applications.