The Development of Novel and Sustainable Surface Preparation Processes for Steels Using Environmentally Friendly Solutions

The Industry and Innovation Research Institute (I2Ri) draws on talents, expertise and facilities across Sheffield Hallam University. The vision is to be the leading provider of applied research excellence delivering materials, computing, science and engineering innovations meeting the development needs of industry.

PhD Research Topic

The global economic cost of corrosion is approximately 3.4% GDP or $2.5 trillion and therefore preventing or reducing the rate at which it occurs is of great importance to lower the economic and environmental cost of manufacture whilst also allowing for more sustainable use of materials.

Steel is extensively used in many sectors and for numerous applications, from large structures to everyday household appliances. One of the most effective ways to protect steels from corrosion is to apply coatings, such as paints. However, when manufacturing steel sheet and plate adherent oxide scale can form. Applying a coating directly to this can results in poor coating performance and therefore it is vital to remove this to maximise the lifespan of products.

Scale can be removed using acids in a process known as ‘pickling’. However, these processes use chemicals which are harmful to both workers and the environment. Furthermore, they can take a long time to achieve results. Applying an electric current while pickling can have the advantage of reducing process times and also permitting the use of more benign solutions.

The production of steel plate and sheet requires the use of high temperatures which results in the formation of a thin adherent oxide layer, typically referred to as mill scale. This oxide layer provides limited corrosion protection as it contains microcracks allowing access to the substrate where corrosion can occur. The corrosion resistance of steel can be enhanced through the application of coatings. However, the presence of mill scale reduces the coating performance due to the formation of coating defects such as blisters, cracks and delamination, typically associated with poor coating adhesion. Therefore, the removal of mill scale is a critical step in enhancing the corrosion protection of steel. This process typically involves the immersion of the steel in harsh acidic chemicals such as hydrochloric and sulphuric acid which react with the mill scale allowing it to be easily removed. Inorganic inhibitors are also included to prevent the acids from attacking the substrate. These pickling solutions require high levels of safety precautions to protect workers and the environment. Currently there is a drive to minimise the ecological impact of manufacture, moving away from these traditional solutions to more sustainable environmentally friendly substitutes form organic sources. Further benefits can accrue from adopting substitutes from sustainable sources, such as food waste.

The electrolytic cleaning technique offers an eco-friendly approach to enable the efficient removal of scale, where hydrogen is produced at the substrate-scale interface allowing it to be easily removed. However, this can take a long time which is unrealistic in high throughput situations. Therefore this PhD aims to determine an effective combination of benign pickling solution and electrolytic cleaning methods and optimising the process to create a fast, safe and environmentally friendly cleaning solution.

The PhD student will receive training and support from the supervisory team and other members of staff to allow them to gain experience in the analysis and interpretation of results gathered from various analytical techniques, including AFM, SEM, TEM, XRD and Raman. Using mass loss and electrochemical techniques, the efficiency of traditional pickling solutions and inhibitors will be determined and compared against the newly developed solutions. Finally, the project will explore how electrolytic cleaning methods can impact the mill scale removal, before determining the effectiveness of the combined environmentally friendly pickling solution and electrolytic cleaning method. 

Eligibility

Applicants should hold a 1st or 2:1 Honours degree in material science, chemical engineering or a related discipline. A Master’s degree in a related area is desirable. We welcome applications from all candidates irrespective of age, pregnancy and maternity, disability, gender, gender identity, sexual orientation, race, religion or belief, or marital or civil partnership status.

International candidates are required to provide an IELTS certificate with a score of at least 6.5 overall, and a minimum of 6.0 in all components. For further information on English Language requirements, please click here.

For further details on entry requirements, please click here.

How to apply

All applications must be submitted using the online application form. To apply, click here. In your application, be sure to include the title of the project that you are applying for.

As part of your application, please upload:

• A research proposal (max. 1500 words) in your own words, briefly outlining the proposed research, the current knowledge and context referencing key background literature; a proposed methodology or approach to answer the key questions, and any potential significance or impact of the research
• Copy of your highest degree certificate
• Non-UK applicants must submit IELTs results (or equivalent) taken in the last two years and a copy of their passport.

Applicants must provide 2 references, with at least one to be academic. References must be received directly from the referees.

We strongly recommend you contact the lead academic, Matthew Kitchen [email protected], to discuss your application.

For information on how to apply please visit https://www.shu.ac.uk/research/degrees