Experimental studies on Drilling of 410 Stainless Steel

Abstract

Stainless Steel 410 (SS410) is 12% chromium martensitic steel which can be heat treated to obtain wide range of mechanical properties. Due to its strong corrosion resistance and excellent combination of toughness and strength, it is used for furnace parts, micrometer parts, steam turbine buckets, blades, pump parts, petrochemical equipments, etc.However, during machining of SS410, difficulties are there due to its low thermal conductivity, high ductility and work hardening which can be minimized by using suitable machining parameters and cutting fluids. Therefore, now a day’s research works have been focused towards machinability of SS410 through different machining processes. Among different machining processes, many works have not been started on drilling of SS410. Drilled holes are used to receive screws, bolts, shafts, steam pipes, fitting of furniture and equipment. By considering the above applications and challenges in machining of this material, drilling experiments were conducted on SS410 to analyze the effect of drilling parameters and machining environment on surface roughness and machining time. Experiments were conducted in a jig boring machine with HSS twist drill of ∅10 mm on 5 mm thickness SS410 plate.Drilling tests were carried out as per Taguchi’s L9 array using three cutting speeds (Vc: 11, 16 and 21 m/min) and three feeds (f: 0.02, 0.05 and 0.08 mm/rev) using three different cutting fluids (castor oil, kerosene and coconut oil). Surface roughness (Ra) values were decreased from 7.326 to 2.423 µm with increase in 'Vc' and decrease in 'f' and machining time was increased from 7.4 to 31.5 seconds with increase in 'Vc' and 'f'. Optimum process parameters were identified and verified experimentally to improve the machinability of the SS410. Coconut oil medium gave good machinability results at higher 'Vc' and 'f'.