Impact: Improving the production process of ferritic stainless steels

Used widely in everyday applications such as mufflers, exhaust systems and kitchen counters and sinks, ferritic stainless steels (FSSs) are valued for their excellent resistance to corrosion and low cost compared to other stainless steel products.

However, problems remain in the production of FSSs, in particular, the ‘sticking’ that occurs in the hot rolling process due to the lack of oxide scale protection.

Severe sticking results in fragments of rolled materials getting stuck to the work roll surface, causing damage resulting in a reduced production rate and increased consumption of work rolls.

Sticking also deteriorates the surface quality of the steel strips produced and those with serious defects cannot then be used directly in the manufacturing of the final FSSs product.

To rectify damaged strips, manual polishing and finishing must be carried out to smooth the strip surface, which again increases production costs and can cause environmental and health problems.

In a collaboration with China’s largest steel company Baosteel, researchers from the UOW School of Engineering including Professor Zhengyi Jiang, are working to solve the impact of ‘sticking’ in the hot rolling process of FSS production and improve the associated economic, environmental and health impacts.

Research has included investigating the kinetics of oxide scale growth on FSSs in humid environments (replicating the condition of real production), oxide scale formation in the reheating furnace and during hot rolling passes, oxide scale’s deformation behaviour and its effect on friction between the roll and the strip, and roles of extreme pressure (EP) agent additive in lubricant in hot rolling of stainless steels.

It has led to a better understanding of surface deterioration in the hot rolling of FSSs and to the development of control strategies to optimise reheating temperature before rolling, as well as the application of a specially developed, novel EP agent additive lubricant in the hot rolling process.

These innovations have been applied on Baosteel’s stainless steel production line, and defect-free FSS products have been successfully produced.

This has had economic benefits for FSSs manufacturers, as well as reducing the impact of remediating damaged strips on the environment and workers’ health. 

    Professor Zhengyi Jiang
    Dr Jingwei Zhao
    Dr Dongbin Wei
    Xiawei Cheng
    Liang Hao
    Bob de Jong
    Dr Laizhu Jiang
    Dr Suzhen Luo
    Jianguo Peng
    Ming Luo
    Li Ma