The molten iron used for smelting SPA-H steel plate must be pretreated by molten iron desulfurization, the sulfur content of the molten iron is ≤0.010% before entering the converter, and the slag on the surface of the molten iron must be removed. Nickel plates, copper pellets or nickel-copper alloys are added to the converter along with the scrap steel. The carbon content of the converter smelting SPA-H steel plate is required to be ≤0.06% to prevent the molten steel from over-oxidizing.
For SPA-H steel plate, the tapping temperature is controlled at 1640～1660℃, and synthetic slag is added to the ladle for baking before tapping. The slag stopper and the slag ball are used for double slag stop tapping. The tapping process adds silicon calcium barium, aluminum manganese titanium, silicomanganese, ferrosilicon, medium carbon ferrochrome, and ferrophosphorus for deoxidation and alloying.
After repeated smelting of the SPA-H steel plate, it can be seen that the yield strength, tensile strength and elongation of the steel are relatively stable, and the fluctuation range is small. The mechanical properties of SPA-H steel plate far exceed the requirements of the corresponding standards. The material has a low yield ratio, is easy to form, has a high work hardening rate, and has good performance.
