PhD Studentship: Quantifying the effect of vanadium additions in rail steels

This project is a 4-year Engineering Doctorate supported by British Steel as part of the EPSRC Centre for Doctoral Training in Advanced Metallic Systems.

The project aims to enhance and extend British Steel’s portfolio of long products – particularly rails and sections -- by optimisation of the steel chemistry and processing conditions and therefore the mechanical properties of the product supplied to our customers. In particular, the emphasis will be on understanding the role of vanadium, which is added as a microalloying element to a range of steel products, in different microstructures:
o During the initial production of the hot rolled product
o During subsequent downstream processing, such as heat treatment and welding

Vanadium combines with C and/or N in the steel during the hot rolling and cooling process to form precipitates which ideally are of nano-scale. A number of process and product factors influence the precipitation of the vanadium and thus the development of the required mechanical properties in these steels, and not all of these factor combinations are properly understood. A more detailed understanding of the effects of these parameters is required. However, ferrovanadium has historically been expensive and therefore its addition should be controlled to obtain the optimum combination of mechanical properties in the final product at the lowest alloy and processing cost.

It is envisaged that the programme of work should consist of the following phases:-

(a) Gain a detailed understanding of the use of vanadium in current steel products, such as rail and structural sections. Investigate the correlation between the steel compositions, microstructure and process route and the subsequent mechanical properties. Understand why V is used for these products instead of other alloying additions, e.g. Nb or Ti.

(b) To understand and characterise the precipitation behaviour of Vanadium, in the form of VN, VC or mixed carbonitrides, in different steel microstructures including ferrite (for sections), pearlite (for conventional rail) and bainite (for high performance rail products).

(c) To understand and characterise the precipitation behaviour of Vanadium under different processing conditions, including natural air cooling, accelerated cooling and heat treatment.

(d) To determine the optimum combination of V and C required for improved wear resistance of pearlitic rail grades.

(e) To understand and characterise the precipitation behaviour of Vanadium in the specific case of welding of rails, especially in the heat affected zone (HAZ).

The research engineer will be located at Scunthorpe works throughout the project and will be resident with the technical team dealing with the products on the daily basis. The production facilities are all located on-site. Access to the industrial supervisor will be on a weekly if not daily basis. Whilst on-site, the research engineer will constitute part of the technical team and will attend the required briefings, including those on safety and business performance. There will be considerable interaction with other business functions, including production, engineering, commercial and marketing. There will be opportunities to visit other steelworks as part of the project.

The Advanced Metallic Systems CDT is a 4 year programme hosted jointly by the universities of Manchester and Sheffield building on their complimentary expertise and international reputations in materials science and engineering research. In year 1, students from a range of disciplinary backgrounds undertake taught courses in core materials topics. Doctoral research begins after 6 months. Our transferable skills and personal development programme leads to a Diploma in Professional Skills. Visit our website for more information www.metallicsCDT.co.uk

Funding Notes

Applicants should have or expect to obtain a first class, upper second class or postgraduate masters level degree in chemistry, physics or engineering. Please contact us if you wish to discuss your suitability for the programme.

The four-year studentship includes tuition fees and a minimum stipend of £18,000pa, supported by British Steel.