Effects of Shallow and Deep Cryogenic Treatment on Tool Flank Wear and Surface Roughness in Machining 41Cr4 Steel

This study presents the affects of cryogenic treatment on flank wear (Vb) and surface roughness (Ra) in machining 41Cr4 steel with shallow (SCT (15 h at -80 degrees C)) and deep (DCT (15 h at -196 degrees C)) cryogenically treated carbide tools. The study revealed that the cryogenic treatment increases the hardness and wear resistance of coated carbide tools and improves the surface roughness, thanks to the changes in the microstructure. The eta-phase is approximately 17.5 and 24.64% higher in the shallow and deep cryogenically treated tool's microstructure than in the untreated tool (U). The best machining performance was founded with the deep cryogenically treated cutting tool. Compared to the untreated tool, shallow and deep cryogenic treatment increased the hardness of the cutting tools by approximately 8.66 and 10.17%. Compared to the untreated cutting tool, the deep cryogenically treated tool was less worn at rates ranging from 13.04 to 18.60% and provided a lower average surface roughness between 2.49 and 20.15%. With increasing feed rate and cutting speed, the amount of cutting tool flank wear also increased. While the surface roughness values decreased slightly with increasing cutting speed, the increasing feed rate caused the surface roughness to increase significantly. The analysis of variance results showed that the most significant parameter on the cutting tool flank wear was heat treatment with a rate of 67.34%, and the most influential parameter on the surface roughness was the feed rate with a rate of 96.33%.