Effect of Coiling Temperature on Microstructure and Properties of Hot Rolled Double-sided Enamelled Steel

The effects of two coiling temperatures（560,700℃） on the microstructure and properties of hot-rolled double-sided enamelled steel were studied under laboratory conditions. The results show that the bainite appears in the local structure of the experimental steel at low coiling temperature, and the precipitated particles show interphase precipitation, and the size is mainly ＜10 nm. While rolled at high coiling temperature, the microstructure of the experimental steel is uniform ferrite and the precipitated particles are dispersed, and the size is mainly 5-20 nm. There is little difference of strength of the experimental steels at the two coiling temperatures, the yield strength is 558-574 MPa, the tensile strength is 662-665 MPa, but the experimental steel has higher elongation at high temperature. When the experimental steel is enamelled twice, the yield strength decreases to 359-374 MPa, the tensile strength decreases to 440-447 MPa, and the elongation increases to 38.5%. The high coiling temperature experimental steel has higher hydrogen permeation time, and the hydrogen permeation time of the steel plate is significantly reduced after enameling. There is no scale explosion in the two experimental steels after double-sided enamelling.