Variations of microstructure and resistance to fish-scaling of a hot rolled enamel steel before and after enamel firing

Different temperature enamel firings were applied on a Ti-containing hot rolled enamel steel. The microstructure, mechanical properties and resistance to fish-scaling were characterized by optical microscopy, transmission electron microscopy, tensile test and hydrogen permeation test. The results show that both ferrite grain size and TiC particles size were increased after enamel firing. The yield strength, tensile strength and resistance to fish-scaling of experimental steel decrease with increasing firing temperature, which can be attributed to the increase in ferrite grain size and TiC particles size. TiC precipitates significantly affect the resistance to fish-scaling, and small sized TiC particles are beneficial for the high resistance to fish-scaling.