Cold Rotary Forging of Inconel 718

Abstract

The present work includes an in-depth study of microstructure and mechanical property development in a cold rotary forged component manufactured from Inconel 718 alloy. This work is pioneering in that there is no detailed study available in the literature focussing on cold rotary forging of Inconel 718. A tubular preform of 6 mm wall thickness was cold rotary forged into a 90 degree flange part followed by annealing with double aging. The present study provides a thorough analysis of microstructure, hardness and surface roughness evolution from as-received to final cold rotary forged and heat-treated condition including crystallographic texture changes occurring at different stages. The solution-annealed condition of the preform was found to be most suitable for cold rotary forging of Inconel 718. An annealing treatment followed by double-aging imparted desired properties such as homogeneous microstructure, uniform hardness distribution and improved surface roughness into the cold rotary forged Inconel 718 flange. The cold rotary forging can be a cost-effective route for manufacture of axisymmetric components with high material yield and low buy-to-fly ratio for expensive materials such as Inconel 718.

An investigation into the behaviour of selected boundary regime lubricants when cold forging steel under rolling-sliding conditions

“…In order to determine whether promising lubricant behaviours are replicated during manufacture of larger, more complex components, further studies analogous to that presented here are required. In this regard, it is pertinent that when a tubular Inconel 718 preform of 6 mm wall thickness was cold forged into a 90° flange, workpiece temperatures were comparable to those during this cylinder upsetting operation [7]. Of particular interest are whether the synergism between MoS2 and ashless phosphate esters in mineral oil, and the positive relationship between friction at the upper interface and homogeneity of deformation, continue.…”

“…This has enabled a trend away from traditional high-volume manufacture of circular components such as gears and bearing housings towards more specialised, high-value products. Methods under development include near net-shape manufacture of axisymmetric components with a 90° bend flange from tubular preforms for the aerospace industry [5][6][7],…”

Numerical and Experimental Investigations on Residual Stress and Hardness within a Cold Forward Extruded Preform

“…However, when considering the operating environment of the drive shaft, it has to satisfy a basic series of critical requirements such as sufficient structural stiffness and mechanical strength against torque, substantial durability, and so forth. To this end, the residual stress and the plastic deformation damage within the preform as the intermediate workpiece of the drive shaft have to be managed at an appropriate level [ 28 , 29 , 30 , 31 , 32 ].…”

Forming characteristics and mechanism of double-roll rotary forging for large-diameter and thin-walled metal discs

“…Based on G.liu's study, Xinghui Han and Lin Hua [11][12][13][14][15] established 3D elastoplastic finite element model to study the forming characteristics of discs and rings, in order to further improve the accuracy of the 3D elastoplastic finite element model, they revised the friction coefficient [16], and studied the contact pressure, slip distance and mold wear [17][18][19][20][21], which significantly promote the reliability of FEM for forging application. Apart from these studies focus on the cold rotary forging process, Paranjayee Mandal and Yong Zheng [22][23][24][25][26] studied the hot rotary forging by investigating the forming characteristics of flanges and discs, which is more favorable for less deformable materials.…”