A method for smelting stainless steel in a top-blown converter

Abstract

The invention relates to a method for smelting stainless steel by a top-blown converter process, comprising the following steps: 1) requirements on molten iron: wherein in the molten iron, the weightpercent of Si is 0.25-0.55%, and the weight percent of P is smaller than or equal to 0. 07%, and the weight percent of S is smaller than or equal to 0. 002% in the molten iron after desulfurization; 2) a duplex process adopted by converter smelting, wherein the control on the smelting process of a dephosphorization furnace is as follows: a, a charging system; b, an oxygen supply system; and c, semi-steel tapping; and the control on the smelting process of a decarbonization furnace: a, a charging system; b, an oxygen supply system; and c, end point tapping; and 3) converter alloying and steel tapping. The method can realize stainless steel production through the traditional top-blown converter process, greatly shortens the stainless steel production flow and reduces the stainless steel production cost; the production process equipment is simple and easy to control, and the loss of refractory material is greatly reduced because the highest smelting temperature is less than 1720 DEG C.

Description

technical field

[0001] The invention relates to the technical field of stainless steel smelting, in particular to a method for blowing stainless steel in a top-blown converter. Background technique

[0002] Ferritic stainless steel, martensitic stainless steel, and austenitic stainless steel are three types of stainless steel that came out at the same time in the early 20th century. Ferritic stainless steel has good corrosion resistance and oxidation resistance, and its stress corrosion performance is better than that of austenitic stainless steel. Stainless steel is mostly used to manufacture parts that are resistant to corrosion by atmosphere, water vapor, water and oxidizing acids. Due to limited nickel resources, the price of chromium-nickel austenitic stainless steel is relatively high, while the nickel content of ferritic stainless steel is extremely low, and the cost and price are relatively low. Therefore, ferritic stainless steel has achieved considerable developmen...

Examples

Embodiment 1

[0043] In this example, a 100t top-blown converter is used to smelt stainless steel SUS410L;

[0044] The first semi-steel (for the double dephosphorization method, the first smelting is in the dephosphorization furnace, the main smelting task is dephosphorization, because the carbon content in the steel is about 2% when the steel is tapped, it is a semi-finished product, so it is commonly called the first semi-steel; the second The secondary smelting is in the decarburization furnace, and the main smelting task is to achieve the decarburization target required by the steel type, so it is called the second half steel):

[0045] 92t molten iron, carbon content W[C]=4.29%, silicon content W[Si]=0.45%, phosphorus content W[P]=0.054%, sulfur content W[S]=0.022%, temperature 1334°C;

[0046] Scrap steel 6t, lime addition 55kg / t steel, light burnt dolomite addition 11kg / t steel;

[0047] Oxygen pressure 0.65Mpa, total oxygen accumulation 3079Nm 3 ;Tapping carbon content W[C]=2.45%...

Embodiment 2

[0057] In this example, a 100t top-blown converter is used to smelt stainless steel SUS410L;

[0058] 1. Front half steel:

[0059] 90t molten iron, carbon content W[C]=4.4%, silicon content W[Si]=0.55%, phosphorus content W[P]=0.06%, sulfur content W[S]=0.025%, molten iron temperature 1345°C;

[0060] Steel scrap 8t, lime addition 50kg / t. steel, light burnt dolomite addition 13kg / t. steel;

[0061] Oxygen pressure 0.65Mpa, total oxygen accumulation 3250Nm 3 ; Semi-steel tapping carbon content W[C]=2.3%, silicon content W[Si]=0.02%, phosphorus content W[P]=0.0095%, sulfur content W[S]=0.005%, temperature 1450°C.

[0062] 2. Rear half steel:

[0063] The amount of lime added is 30kg / t steel, the amount of light burnt dolomite added is 12kg / t. steel; the oxygen pressure is 0.80Mpa, and the oxygen accumulation is 4200Nm 3 ; Decarburization end carbon content W[C]=0.035%, phosphorus content W[P]=0.005%, sulfur content W[S]=0.0065%, tapping temperature 1689 ℃.

[0064] 2. Conv...

technical field

[0001] The invention relates to the technical field of stainless steel smelting, in particular to a method for blowing stainless steel in a top-blown converter. Background technique

[0002] Ferritic stainless steel, martensitic stainless steel, and austenitic stainless steel are three types of stainless steel that came out at the same time in the early 20th century. Ferritic stainless steel has good corrosion resistance and oxidation resistance, and its stress corrosion performance is better than that of austenitic stainless steel. Stainless steel is mostly used to manufacture parts that are resistant to corrosion by atmosphere, water vapor, water and oxidizing acids. Due to limited nickel resources, the price of chromium-nickel austenitic stainless steel is relatively high, while the nickel content of ferritic stainless steel is extremely low, and the cost and price are relatively low. Therefore, ferritic stainless steel has achieved considerable developmen...

Examples

Embodiment 1

[0043] In this example, a 100t top-blown converter is used to smelt stainless steel SUS410L;

[0044] The first semi-steel (for the double dephosphorization method, the first smelting is in the dephosphorization furnace, the main smelting task is dephosphorization, because the carbon content in the steel is about 2% when the steel is tapped, it is a semi-finished product, so it is commonly called the first semi-steel; the second The secondary smelting is in the decarburization furnace, and the main smelting task is to achieve the decarburization target required by the steel type, so it is called the second half steel):

[0045] 92t molten iron, carbon content W[C]=4.29%, silicon content W[Si]=0.45%, phosphorus content W[P]=0.054%, sulfur content W[S]=0.022%, temperature 1334°C;

[0046] Scrap steel 6t, lime addition 55kg / t steel, light burnt dolomite addition 11kg / t steel;

[0047] Oxygen pressure 0.65Mpa, total oxygen accumulation 3079Nm 3 ;Tapping carbon content W[C]=2.45%...

Embodiment 2

[0057] In this example, a 100t top-blown converter is used to smelt stainless steel SUS410L;

[0058] 1. Front half steel:

[0059] 90t molten iron, carbon content W[C]=4.4%, silicon content W[Si]=0.55%, phosphorus content W[P]=0.06%, sulfur content W[S]=0.025%, molten iron temperature 1345°C;

[0060] Steel scrap 8t, lime addition 50kg / t. steel, light burnt dolomite addition 13kg / t. steel;

[0061] Oxygen pressure 0.65Mpa, total oxygen accumulation 3250Nm 3 ; Semi-steel tapping carbon content W[C]=2.3%, silicon content W[Si]=0.02%, phosphorus content W[P]=0.0095%, sulfur content W[S]=0.005%, temperature 1450°C.

[0062] 2. Rear half steel:

[0063] The amount of lime added is 30kg / t steel, the amount of light burnt dolomite added is 12kg / t. steel; the oxygen pressure is 0.80Mpa, and the oxygen accumulation is 4200Nm 3 ; Decarburization end carbon content W[C]=0.035%, phosphorus content W[P]=0.005%, sulfur content W[S]=0.0065%, tapping temperature 1689 ℃.

[0064] 2. Conv...