Effect of cutting fluid on precision machined surface integrity of heat-resistant stainless steel

Abstract

The machined surface integrity of blades is of utmost importance in the power equipment manufacturing industry. Recently, many blade accidents have been attributable to the misuse of cutting fluids that were necessary in the actual machining of difficult-to-cut materials, but the effect of the cutting fluid on surface integrity and service performance has been persistently neglected. In this article, an investigation into the effect of cutting fluids on the surface quality of a typical blade material was undertaken, combined with properties of two universal cutting fluids. Element composition, surface morphology, residual stress and hardness of the machined surfaces were investigated. The results indicated that cutting fluids could not reduce cutting forces in precision machining. There were some places where local and irregular elemental Cr loss was incurred when machined with the additive Cl, and the depth of Cr loss was 1–2 µm. The machined surface under CF-206 was smooth, and the roughness of CF-210 was the highest. The tensile residual stresses of dry cutting were the highest, whereas those of CF-210 were the lowest. Surface work hardening under cutting fluids was higher, with depths of 20–30 µm. These results are significant for the control of precision machined surfaces and subsurfaces of blades with high integrity and service performance.