International Journal of Innovations in Engineering and Technology (IJIET) http://dx.doi.org/10.21172/ijiet.124.04 Volume 12 Issue 4 March 2019 021 ISSN: 2319-1058 Machining Behavior of En24 and En36c Steels Nikhil Bharat 1 , Vishal Mishra 2 , Dr Kalyan Chakraborty 3 1,2 M.Tech (Mechanical) Student, Department of Mechanical Engineering National Institute of Technology, Silchar, Assam 3 Associate Professor, Department of Mechanical Engineering National Institute of Technology, Silchar, Assam Abstract EN24 and EN36C steels are among the steels that are used in dynamic environment and in heavy duty applications. The paper presents the machinability of EN24 and EN36C steels with reference to turning of the work materials on lathe using carbide insert. Principal aim of investigation was to know the mechanism of chip formation and von Mises stress (VMS) generation during machining. Severe plastic deformation occurs in the primary deformation zone (PDZ) and subsequently chip forms and von Mises stress generates. Cutting velocity, feed and depth of cut (d.o.c) are the input parameters for machining on work material and chip reduction co-efficient (CRC) and von Mises stress (VMS) are the output parameters. 3 3 factorial design of experiment was considered to conduct the experiment. The von Mises stress (VMS) was determined employing CRC and material properties namely strain hardening exponent ‘n’ and strength co- efficient ‘K’. Presence of residual stress on machined item has to be identified as this may cause some detrimental effect on machined component. Therefore, presence of such stress was identified through XRD study in the present work. Finally, behavior of chip material during formation was also observed by SEM and EDX examination. Keywords Chip reduction coefficient (CRC); von Mises stress (VMS); Chip formation mechanism. I. INTRODUCTION EN24 and EN36C steels are usually used for production of various mechanical components. These materials are processed extensively by machining. Therefore, present study is aimed at to determine machinability of these materials. Machining response parameters like tool wear, surface roughness, cutting forces etc are usually considered for machinability assessment. Induced von Mises stress (VMS) on machined surface can be another factor to be considered for machinability assessment. Machining process is based on plastic deformation of work material. Machining chip is formed through plastic deformation only. Chip reduction coefficient(ξ) can be considered as an index of plastic deformation. Machining process is very much influenced by deforming behaviour of work material. It is therefore necessary to incorporate CRC as an index for determination of induced von Mises stress (VMS) on the machined item. Generated von Mises stress (VMS)on the machined component is also strongly influenced by property of the work material. Present work illustrates the method for determination of von Mises stress (VMS) based on deformation index (CRC) and material property namely strength coefficient ‘K’ and strain hardening exponent ‘n’. This method for determination of von Mises stress (VMS) employing ξ, n and K can be considered as most appropriate consideration since von Mises stress (VMS) generation is directly related toplastic deformation and subsequently to property of materials. Literature considering this procedure to determine the von Mises stress (VMS) on the machined component employing ξ, n and K is scarce. Vishal Mishra et al. [1] performed machining on EN24 and EN36C steels using carbide tool and found that tool wear takes place through adhesion and chipping while machining EN24 steel. They also observed that for machining with EN36C steel, tool wear takes place through abrasion. Vishal Mishra et al. [2] studied the effects of von Mises stress (VMS) generation during Machining on EN36C steel. It was observed that EN36C steel showed better results during maching at cutting speed: 60m/min, feed: 0.63mm/rev and doc: 1mm. Geethanjali KS et al. [3] studied the effects of machining on tool forces, power consumption and surface roughness. It was observed that for EN19 steel and EN24 steel, cutting speed has a significant effect on power. Nikhil Bharat et al. [4] conducted experiment on EN24 steel on lathe using carbide tool and concluded that EN24 steel can be machined at higher speed, feed and depth of cut (d.o.c). II. EXPERIMENTAL PROCEDURE In the present study EN24 and EN36C steels are used as work materials having 400mm of length and 110mm of diameter. Machining was performed on central lathe by using tool insert of coated carbide grade. Table 1 and table 2 show the chemical compostion of work material.