Yield improvement in hot forging of differential spider Mathala Prithvi Raj, Manoj Kumar ⇑ , Ajit Kumar Pramanick Department of Forge Technology, National Institute of Foundry and Forge Technology, Ranchi, Jharkhand, India article info Article history: Received 8 February 2020 Accepted 14 February 2020 Available online xxxx Keywords: Yield Die design Effective stress Effective strain rate Finite element method Wear abstract The main aim of the paper is to improve the yield in forging a Differential Spider. Yield is improved by varying the cross-section of the billet from Circular to RCS (Round Cornered Square) and orientation of billet. It is shown that the yield can be improved by employing a billet of RCS cross-section placing the diagonals parallel to the arms. Further improvement is made by modifying the die design in such a way that the die shape allows the material to flow into the arms of the spider, which resulted in a yield of 85%. 91% yield is obtained by completely closing the cavity in the bottom die and allowing the top die to enter into the cavity till the forging process is completed. This is achieved by providing a choke just after the flash land around the body of the spider. This paper also provides a complete die design proce- dure for multi-stage forging of a component. And, also shows the variation of effective-stress distribution, effective-strain distribution, temperature distribution and load with change in the equipment and billet temperature. For completely filled dies in varies cases wear depth is estimated. To estimate the metal flow and die filling a finite element method based simulation software DEFORM-3D is used. Ó 2020 Elsevier Ltd. All rights reserved. Selection and of the scientific committee of the 10th International Conference of Materials Processing and Characterization. 1. Introduction It is generally known that the cost of production in manufactur- ing a component through forging is high. The remarkable improve- ments in other manufacturing methods and economic pressures from international competition demand not only a precise product but also an economic product. The cost of a forged component mainly depends on the cost of the raw material. About 50% cost of the forging comprises of the raw material cost, 30% Labour cost, overhead cost and forging equipment cost. And remaining 20% comprises Tooling cost and secondary operations cost [1]. Hence the cost of the forging can be greatly reduced by using cheaper alternative materials or by reducing the amount of material used for forging. While forging about 10–15% of the raw material is wasted in the form of flash [2]. But while forging a component like spider more than 25% raw material is flushed out of the die cavity in the form of flash which is wastage. This results in higher raw material requirement which implies higher cost. Hence in this paper an attempt is made to reduce the raw material requirement in closed die hot forging of a spider. The previous work [3,4] shows development of mesh and mul- tistage modelling for spider forging, in all the works a circular cross section billet is used to simulate and manufacture the die, and large amount of material is expelled into flash. In the present work a billet of RCS cross section with lesser raw material is used to sim- ulate the process in DEFORM-3D a Finite Element based software. Further the die design is modified by providing a choke and making the impression in the cavity of the bottom die. By these ways mate- rial flow into the gutter is reduced. Wear depth is estimated in var- ious cases by considering Archard’s wear model. 2. Design for multi-stage forging In multi stage forging the final shape of the component is obtained by deforming the material in various stages. The final dimensions of the component are obtained while forging in the fin- isher dies. All the steps preceding the finisher are called preforms. There are various preforms like Fuller, Edger, Bender, Upset and Blocker. For current component three stage forging is designed and the steps considered are Upset, Blocker and Finisher. https://doi.org/10.1016/j.matpr.2020.02.642 2214-7853/Ó 2020 Elsevier Ltd. All rights reserved. Selection and of the scientific committee of the 10th International Conference of Materials Processing and Characterization. ⇑ Corresponding author. E-mail address: manojkumar.nifft@gov.in (Manoj Kumar). Materials Today: Proceedings xxx (xxxx) xxx Contents lists available at ScienceDirect Materials Today: Proceedings journal homepage: www.elsevier.com/locate/matpr Please cite this article as: M. Prithvi Raj, Manoj Kumar and A. K. Pramanick, Yield improvement in hot forging of differential spider, Materials Today: Pro- ceedings, https://doi.org/10.1016/j.matpr.2020.02.642