Research into the microstructural and mechanical property evolution of high value titanium and steel forgings via a range of thermomechanical processes and simulations.

Forging is the oldest recorded thermo-mechanical metal forming process. Initially, forging relied on the skill of artisan smiths working with a relatively limited number of materials, principally wrought iron, copper-base alloys, lead, silver and gold to produce items such as agricultural implements, armour and weapons, coinage and jewellery.

With the advent of the Industrial Revolution came the large-scale, power-assisted mechanisation of forging, beginning its transformation into an advanced technology that is capable today of producing components ranging in size and complexity from bolts to turbine rotor blades and aircraft fuselage and wing structures.

Forging-related research within the STAR group is focused on the development industrial forging practices to optimise component performance in extreme environments such as the production of super duplex stainless steel swivel hub assemblies for sub-sea oil and gas pipeline and associated riser systems. Here specification of correct forging parameters is key in producing precipitate-free microstructures that enable toughness and corrosion resistance to be maintained at low temperatures.

Novel forging techniques are also being developed within the group for non-ferrous powder metallurgy applications such as the production of lightweight connecting rods for internal combustion engines from spark plasma sintered dissimilar titanium alloy preforms. Research in all these aspects of forging is underpinned by predictive computer simulations developed in the DEFORM® finite element analysis software package as well as laboratory material data generated from the University’s Thermo-Mechanical Compression machine; a servo-controlled 500 kN high-capacity, high-rate complex metal forming simulation system capable of performing multiple deformation steps at temperatures up to 1200℃ with intermediate heating/cooling.

Induction heat treatment of stainless steel at the University of Sheffield

Water quenching of induction heated stainless steel