An Ultra-low-Carbon Steel with Outstanding Fish-Scaling Resistance and Cold Formability for Enameling Applications

Developing specialized, high-performance steels for enameling is in demand as enameled steel products are finding increasingly decorative and protective applications across industries. Here, we present an ultra-low-carbon steel with excellent fish-scaling resistance and cold formability, which essentially warrant its success in enameling applications. Its fish-scaling resistance was examined by both hydrogen permeation tests and visual inspection, and was found to outperform the benchmark steel—interstitial free (IF) steel. The steel’s cold formability was evaluated with the forming limit curve (FLC), proven to be superior to the IF steel under certain loading conditions, e.g., uniaxial tension. Through integrated microscopic characterizations and thermodynamic analyses, it was confirmed that a large amount of uniformly dispersed (Ti, N), (Ti, S), (Ti, C, S), and (Ti, C) containing particles precipitated in the steel, serving as irreversible hydrogen traps and prominently contributing to its outstanding fish-scaling resistance. The possibility of further optimizing the fish-scaling resistance by refining precipitates is outlined with the aid of thermodynamic calculations.