Prevention of surface hot shortness, development of banded structure, and mechanical properties of hot rolled Cu-bearing steel

• The development of microstructural banding and surface hot shortness was studied.
• Effect of cross rolling and cooling method on mechanical properties was evaluated.
• Effect of banding on the anisotropy of mechanical properties was characterized.
• The optimum hot rolling temperature to suppress hot shortness was determined.

The development of microstructural banding and surface hot shortness during hot rolling in a 1.4 wt% Cu-bearing steel was studied. Different hot rolled states were produced by cross rolling, air cooling, and furnace cooling to investigate the effect of initial microstructure on the mechanical properties. It was revealed that to insure the hot workability of Cu-bearing steel against liquid metal embrittlement and prevention of the failure, a good practice is conducting hot working operations at temperatures below the melting point of copper to suppress the formation of liquid Cu-enriched phase that penetrates into grain boundaries. Cross rolling was found to be a promising approach to decrease the anisotropy of the rolled sheets resulted from the presence of the banded structure. Moreover, air-cooling yielded maximum strength due to its resultant fine and complex microstructure. These results can find application in processing and optimization of mechanical properties of steel sheets.

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