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The input shafts are conventionally developed through Hot forging route. Considering upcoming new technologies the same part was developed through cold forging route which resulting in better Mechanical properties than existing hot forging process. It has added benefit of cost as well as environmental friendly. Generally, the part like Input shaft which having gear teeth, splines etc., will be manufactured through Hot forging process due to degree of deformation, availability of press capacity, diameter variations etc., This process consumes more energy in terms of electricity for heating the bar and also creates pollution to the atmosphere. Automotive input shaft design modified to accommodate cold forging process route to develop the shaft with press capacity of 2500T which gives considerable benefit in terms of mechanical and metallurgical Properties, close dimensional tolerances, less machining time, higher material yield when compared to hot forging and metal cutting operation.

In general, the automotive drive shafts are being manufactured by one of the conventional manufacturing process sequence i.e. Hot Forging, Normalizing & subsequently case hardening and tempering to achieve the desired functional strength requirements. The case hardening process like induction hardening or gas carburizing shall be decided based on geometry, material chemistry and functional requirements. The part like drive shafts which are subjected to torsional load at the surface and bending load at core during application. As per CAE analysis, the torsional and bending stress will act upon 40-50% of the shaft diameter from the surface. These property requirements are achieved through normalizing followed by induction hardening process. The study has been done to eliminate the normalizing process by increasing the case depth around 20% without affecting the functional requirements as mentioned.

This study on optimum magnification at which Retained austenite to be evaluated by comparing the difference in determining the retained austenite in low carbon carburizing alloy steel using the optical metallurgical micrographic method and X-ray diffraction method. The retained austenite phase will be in surface and color is white in nature also its presented in between the martensite needles. It can be distinguished as separate micro-constituents by using image analyzing software. In another method the RA measurements were carried out on the surface by PROTO iXRD Retained austenite measuring system using Cr K radiation. The (211) and (200) reflections of Martensite and (220) and (200) reflections of Austenite were made for this estimation. However, the calculated values of retained austenite by metallurgical microscope in different magnifications are not identical.