Tool wear effects on white and dark layer formation in hard turning of AISI 52100 steel

In the present investigation a series of orthogonal hard turning tests were conducted to study the effects of tool wear and cutting parameters (cutting speed and feed rate), on white and dark layer formation in hardened AISI 52100 bearing steel, using PCBN inserts. Experimental results were presented including quantification of tool wear and microstructure analysis of the machined surfaces. The experimental results were compared with a newly developed finite elements (FE) model that enables to capture the effect of cutting conditions and tool wear on the microstructural changes occurring at the machined surface. The results showed that cutting regime parameters and, especially, tool wear affect noticeably white and dark layers formation.