Effect of deep cryogenic treatment on wear resistance and tool life of M2 HSS drill

The influence of deep cryogenic treatment on wear resistance and tool life of M2 HSS drills in high-speed dry drilling configuration of carbon steels was studied. The experimental results indicated 77 and 126% improvement in cryogenic-treated and cryogenic- and temper-treated drill lives, respectively. The results of wear rate test were in agreement with drill life test. Chemical composition of chips were also reported to show the onset of seizure in drilling test and the consequence of seizure in promoting dissolution wear by diffusion mechanism. Wear resistance improvement was mainly attributed to the resistance of cryogenically treated drills against diffusion wear mechanism, due to the formation of fine and homogeneous carbide particles during cryogenic treatment. Additionally, transformation of retained austenite to martensite played an effective role, i.e. improved hardness values.