Machining of hardened steel—Experimental investigations, performance modeling and cooling techniques: A review

•Coated carbide tools: encouraging potential for hard turning.•Hard turning: use of coolants and various cooling techniques.•Coated carbide tools: economical alternative to costly PCBN and ceramic tools.•Tool materials and microgeometry plays a pivotal role in hard turning.•Hard turning: modeling of tool wear and cutting force.

The researchers have worked on many facets of machining of hardened steel using different tool materials and came up with their own recommendations. Researchers have tried to investigate the effects of cutting parameters, tool materials, different coatings and tool geometry on different machinability aspects like, the tool life, surface roughness, cutting forces, chip morphology, residual stresses and the tool–chip interface temperature under dry and/or semi-dry and/or flood cooling environment during machining of hardened steels while many of them have ventured to characterize the wear phenomenon. Good amount of research has been performed on an analytical and/or numerical and/or empirical modeling of the cutting forces, tool–chip interface temperature, and tool wear under orthogonal/oblique cutting conditions during machining of hardened steels. This paper presents a comprehensive literature review on machining of hardened steels using coated tools, studies related to hard turning, different cooling methods and attempts made so far to model machining performance(s) so as to give proper attention to the various researcher works.