A kind of smelting method of high phosphorus content steel

Abstract

The invention relates to a method for smelting steel with high phosphorus content, which is suitable for a 180-250 ton converter, comprising: adjusting the position of the oxygen lance and the intensity of the oxygen supply according to the amount of oxygen supplied during the blowing process of the converter; End point control; the end point control includes: in terms of mass percentage, MgO is controlled at 15-18%; FeO is controlled at 9-12%; end-point phosphorus is controlled at 0.030%-0.070%; the basicity R of the slag at the end of the converter is controlled at 2.0% -2.5. The smelting method can increase the phosphorus content at the end point of the converter and reduce the consumption of the phosphorus-iron alloy, and is suitable for smelting steel types with a finished product phosphorus content ≥ 0.070% in terms of mass percentage.

Description

technical field

[0001] The invention relates to the technical field of steelmaking, in particular to a method for smelting steel with high phosphorus content. Background technique

[0002] The composition system of weathering steel mainly includes Cr-Ni-Cu-P system and Cr-Ni-Cu system. Among the elements such as Cr, Ni, Cu, P and Si that affect weather resistance, P is the most economical and effective. A small amount of P can greatly improve the weather resistance of steel. Therefore, in weather-resistant steel such as containers, railway vehicles, bridges, power towers, and cement mixing tanks, controlling the higher phosphorus content is conducive to ensuring its excellent weather resistance and weldability. .

[0003] In the conventional process, due to the high oxidative atmosphere of the converter, the phosphorus element is easily oxidized. At the same time, in order to protect the furnace lining, the slag with high alkalinity is generally used for control. Generally...

Examples

Embodiment 1

[0036] A 210-ton top-bottom combined blowing converter is used for smelting, and the specific steps are:

[0037] S1: Put the hot metal from the blast furnace into the converter, and add 15t of steel scrap at the same time. The mass percentages of the hot metal are C: 4.30%, Si: 0.35%, Mn: 0.21%, P: 0.10%.

[0038] S2: The blowing oxygen lance position and oxygen supply intensity are controlled as follows in the converter smelting process: at the stage of oxygen supply 0-20%, the oxygen supply intensity is controlled at 3.3Nm 3 / (min*t), the gun position is controlled at 2300mm; at the stage of oxygen supply 20-40%, the oxygen supply intensity is controlled at 2.9Nm 3 / (min*t), the gun position is controlled at 2500mm; at the stage of oxygen supply 40-90%, the oxygen supply intensity is controlled at 3.2Nm 3 / (min*t), the gun position is controlled at 1800mm; at the stage of oxygen supply 90-100%, the oxygen supply intensity is controlled at 3.2Nm 3 / (min*t), gun position co...

Embodiment 2

[0043] A 210-ton top-bottom combined blowing converter is used for smelting, and the specific steps are:

[0044] S1: Put the hot metal from the blast furnace into the converter, and add 15t of steel scrap at the same time. The mass percentages of the hot metal are C: 4.20%, Si: 0.30%, Mn: 0.14%, P: 0.08%.

[0045] S2: The blowing oxygen lance position and oxygen supply intensity are controlled as follows in the converter smelting process: at the stage of oxygen supply 0-20%, the oxygen supply intensity is controlled at 3.0Nm 3 / (min*t), the gun position is controlled at 2200mm; at the stage of oxygen supply 20-40%, the oxygen supply intensity is controlled at 2.8Nm 3 / (min*t), the gun position is controlled at 2450mm; the oxygen supply intensity is controlled at 3.0Nm at the stage of 40-90% oxygen supply 3 / (min*t), the gun position is controlled at 1600mm; at the stage of oxygen supply 90-100%, the oxygen supply intensity is controlled at 3.0Nm 3 / (min*t), gun position con...

Embodiment 3

[0050] A 210-ton top-bottom combined blowing converter is used for smelting, and the specific steps are:

[0051] S1: Put the hot metal from the blast furnace into the converter, and add 15t of steel scrap at the same time. The mass percentages of the hot metal are C: 4.40%, Si: 0.40%, Mn: 0.25%, P: 0.20%.

[0052] S2: The blowing oxygen lance position and oxygen supply intensity are controlled as follows in the converter smelting process: at the stage of oxygen supply 0-20%, the oxygen supply intensity is controlled at 3.5Nm 3 / (min*t), the gun position is controlled at 2400mm; at the stage of oxygen supply 20-40%, the oxygen supply intensity is controlled at 3.0Nm 3 / (min*t), the gun position is controlled at 2650mm; at the stage of oxygen supply 40-90%, the oxygen supply intensity is controlled at 3.5Nm 3 / (min*t), the gun position is controlled at 2000mm; at the stage of oxygen supply 90-100%, the oxygen supply intensity is controlled at 3.5Nm 3 / (min*t), gun position co...

technical field

[0001] The invention relates to the technical field of steelmaking, in particular to a method for smelting steel with high phosphorus content. Background technique

[0002] The composition system of weathering steel mainly includes Cr-Ni-Cu-P system and Cr-Ni-Cu system. Among the elements such as Cr, Ni, Cu, P and Si that affect weather resistance, P is the most economical and effective. A small amount of P can greatly improve the weather resistance of steel. Therefore, in weather-resistant steel such as containers, railway vehicles, bridges, power towers, and cement mixing tanks, controlling the higher phosphorus content is conducive to ensuring its excellent weather resistance and weldability. .

[0003] In the conventional process, due to the high oxidative atmosphere of the converter, the phosphorus element is easily oxidized. At the same time, in order to protect the furnace lining, the slag with high alkalinity is generally used for control. Generally...

Examples

Embodiment 1

[0036] A 210-ton top-bottom combined blowing converter is used for smelting, and the specific steps are:

[0037] S1: Put the hot metal from the blast furnace into the converter, and add 15t of steel scrap at the same time. The mass percentages of the hot metal are C: 4.30%, Si: 0.35%, Mn: 0.21%, P: 0.10%.

[0038] S2: The blowing oxygen lance position and oxygen supply intensity are controlled as follows in the converter smelting process: at the stage of oxygen supply 0-20%, the oxygen supply intensity is controlled at 3.3Nm 3 / (min*t), the gun position is controlled at 2300mm; at the stage of oxygen supply 20-40%, the oxygen supply intensity is controlled at 2.9Nm 3 / (min*t), the gun position is controlled at 2500mm; at the stage of oxygen supply 40-90%, the oxygen supply intensity is controlled at 3.2Nm 3 / (min*t), the gun position is controlled at 1800mm; at the stage of oxygen supply 90-100%, the oxygen supply intensity is controlled at 3.2Nm 3 / (min*t), gun position co...

Embodiment 2

[0043] A 210-ton top-bottom combined blowing converter is used for smelting, and the specific steps are:

[0044] S1: Put the hot metal from the blast furnace into the converter, and add 15t of steel scrap at the same time. The mass percentages of the hot metal are C: 4.20%, Si: 0.30%, Mn: 0.14%, P: 0.08%.

[0045] S2: The blowing oxygen lance position and oxygen supply intensity are controlled as follows in the converter smelting process: at the stage of oxygen supply 0-20%, the oxygen supply intensity is controlled at 3.0Nm 3 / (min*t), the gun position is controlled at 2200mm; at the stage of oxygen supply 20-40%, the oxygen supply intensity is controlled at 2.8Nm 3 / (min*t), the gun position is controlled at 2450mm; the oxygen supply intensity is controlled at 3.0Nm at the stage of 40-90% oxygen supply 3 / (min*t), the gun position is controlled at 1600mm; at the stage of oxygen supply 90-100%, the oxygen supply intensity is controlled at 3.0Nm 3 / (min*t), gun position con...

Embodiment 3

[0050] A 210-ton top-bottom combined blowing converter is used for smelting, and the specific steps are:

[0051] S1: Put the hot metal from the blast furnace into the converter, and add 15t of steel scrap at the same time. The mass percentages of the hot metal are C: 4.40%, Si: 0.40%, Mn: 0.25%, P: 0.20%.

[0052] S2: The blowing oxygen lance position and oxygen supply intensity are controlled as follows in the converter smelting process: at the stage of oxygen supply 0-20%, the oxygen supply intensity is controlled at 3.5Nm 3 / (min*t), the gun position is controlled at 2400mm; at the stage of oxygen supply 20-40%, the oxygen supply intensity is controlled at 3.0Nm 3 / (min*t), the gun position is controlled at 2650mm; at the stage of oxygen supply 40-90%, the oxygen supply intensity is controlled at 3.5Nm 3 / (min*t), the gun position is controlled at 2000mm; at the stage of oxygen supply 90-100%, the oxygen supply intensity is controlled at 3.5Nm 3 / (min*t), gun position co...

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