Abstract: The effect of two annealing modes (batch annealing and rapid continuous annealing) on the microstructure， mechanical properties and fishscale resistance of boron containing enamel steel was investigated. The results showed that appropriately increasing the mass fraction of Mn， S and adding trace boron， both the tested steel sheets under the two annealing modes had good properties. The strength of the continuous annealed sheet was slightly higher， and the elongation A50 and rmvalues of the continuous annealed sheet were apparently higher than that of the batch annealed sheet. The continuous annealed sheet showed better comprehensive mechanical properties. The hydrogen diffusion rate in the continuous annealed sheet was much lower than that in the batch annealed sheet. This was mainly attributed to large amount of dispersed cementite particles precipitate within ferrite grains which can act as effective hydrogen traps in the ultrafast continuous annealing steels. The match of good mechanical properties with fishscale resistance of the boron contained enamel steel was realized through rapid continuous annealing process.

Key words: enamel steels, rapid continuous annealing, cementite, trace boron, fishscale resistance