Rapid Alloy Prototyping for a range of strip related advanced steel grades

Abstract Over many decades, the traditional route for material product developments, especially in the steel industry has been the laboratory VIM cast route at scale of 25 to 60kg, followed by through-processing of steel ingots involving hot rolling and cooling as well as further downstream processes to simulate finished cold annealed rolled and coated products. This traditional route has so far delivered value for optimising current grades and process routes as well as developing new products prior to production implementation. However, in order to accelerate process and grade developments even smaller scale and faster laboratory synthesis and processing is desired. The AccMet project [1] developed strategies for new alloy development [2,3] and this needs to be further developed to account for the complex processing route for strip steel production. Strategies combining small scale laboratory alloy processing routes, together with mechanical/thermal testing and modelling are being developed, ranging from 20-30g to 4.5 kg [4-8]. This paper summarises current Rapid Alloy Prototyping (RAP) approaches and rationale developed under a new UK Engineering and Physical Sciences Research Council (EPSRC) Prosperity project between Tata Steel and the Universities of Swansea and Warwick (WMG). Specific attention is paid to the overall experimental methodology as well as benefits (throughput) of small-scale manufacturing and testing, the generation of representative microstructures for a range of strip grades as well as ways of integrating new concepts which bridge the physical length scale. A range of experimental facilities (20-40g) based on a powder route and induction melting (IM)/heat treatments is being developed to provide material for hot/cold rolling/annealing prior to mechanical testing. Modelling and testing to account for mechanical test specimen size effects for small scale RAP samples is being carried out to ensure consistent mechanical properties are obtained. This small-scale RAP is also being complemented with an intermediate material route operating between 200g and 4.5kg using centrifugal casting and small size ingot vacuum induction melting respectively to provide additional material and throughput sitting alongside the more traditional pilot-scale 25-30kg route. Finally, the 25-30kg standard route is being reviewed to provide a bridge to the laboratory routes through various innovative concepts. This paper concludes with a review of future activities and challenges for effective development and implementation of a range of small scale experimental and pilot manufacturing lines.