2results about How to "Floating fully" patented technology

This invention belongs to the field of iron and steel smelting technology, specifically relating to a method for controlling the nitrogen content in S460NL steel. The method includes: primary refining in an electric furnace or converter → refining in an LF furnace → refining in a VD furnace → casting. After vacuuming in the VD furnace, nitrogen gas is blown into the ladle through two permeable bricks at the bottom to achieve the target nitrogen content. After nitrogen blowing, argon gas is switched for soft stirring. This invention, by simultaneously blowing nitrogen gas through two permeable bricks at the bottom of the ladle to increase the nitrogen content of high-strength S460NL steel used in wind power flanges after vacuum refining in the VD furnace, offers advantages such as lower cost, higher steel purity, higher composition hit rate, and simpler operation compared to adding manganese nitride ferroalloys.

The application relates to the field of steel production, in particular to a preparation method of a steel plate casting blank. The method comprises the following steps: converter smelting of molten iron, and control of the TFe content in a ladle top slag to obtain first molten steel; RH vacuum refining of the first molten steel to obtain target molten steel; wherein the weight ratio of Als and Alt in the target molten steel is controlled; tundish molten steel is obtained through the target molten steel, and the total oxygen content of the tundish molten steel, the Als loss amount of the tundish molten steel and the weight ratio of Als and Alt in the tundish molten steel are controlled to perform continuous casting pouring to obtain a first casting blank; wherein the process parameters of the continuous casting pouring include: intermediate ladle superheat, argon blowing flow and the amount of protective slag; the first casting blank is in-furnace heated, and the surface temperature of the first casting blank when entering the furnace and the in-furnace time are controlled to obtain a steel plate casting blank. The method reduces the surface defects of the casting blank, and can realize cleaning-free casting blank.