KR840008921A - Method of manufacturing chromium-containing steel - Google Patents

Abstract

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Description

Method of manufacturing chromium-containing steel

Since this is an open matter, no full text was included.

Claims (9)

Starting with a chromium-containing charter containing less than 4.5% by weight of C, at least 0.010% by weight of P, and at least 3.0% by weight of Cr, oxygen and non-oxygen-based In a vessel equipped with a single duct of air with a double tube structure applied to the bottom attachment of the gas, (A) adding a solid carbon source to the chromium-containing molten iron in the vessel in an amount sufficient to provide a chromium-containing molten iron of at least 4.5% by weight at the end of step d. (B) stir the contents in the container by blowing all of the non-oxygen-based gas into it; (C) oxygen is blown into the molten iron to provide a chromium-containing molten iron in the temperature range between 1500 ° C. and 1700 ° C. containing at least 4.5% by weight of C and 0.15% or less by weight of Si, (D) substantially removing the slag formed in the preceding step from the vessel; (E) add de-P flux to the molten iron in the vessel, (F) stirring the contents in the vessel by blowing a non-oxygen based gas into it to promote effective contact of the slag formed with the slag while maintaining the concentration of iron oxide in the slag at a level of at least 1.0% by weight; (G) substantially removing the slack from the container, (H) A method for producing a low P-containing chromium steel, comprising the step of blowing oxygen into a solvent in a container for decarburization while blowing a non-oxygen gas into a branch thereof. The de-P flux is 30-80% by weight of at least one compound selected from fluoride and chlorides, and from 0.4 to 30% by weight of at least one compound selected from lithium oxide and lithium carbonate. Having from 5 to 50% by weight of at least one compound selected from iron oxides and nickel oxide and from 0 to 40% by weight of at least one compound selected from oxides and carbonates of metals with alkalis. The process of claim 1, wherein at least the last part of the step bar is carried out by blowing oxygen into the contents of the container to thereby maintain the concentration of iron oxide in the slack at a level of at least 1.0% by weight. 4. The dephosphorization flux of claim 3 is 30-80% by weight of at least one compound selected from fluorides and chlorides of metals with alkali, and 0.4-30% by weight of at least one compound selected from lithium oxides and lithium carbonates. , 5-50% by weight of at least one compound selected from iron oxides and nickel oxide and 0-40% by weight of at least one compound selected from oxides and carbonates of metals with alkalis. Oxygen and fugitive introduction gases, either alone or in combination with a lance which is applied to the government blowing of oxygen, starting from a chromium-containing molten iron containing 4.5% or less by weight of C, at least 0.010% by weight of P and at least 3.0% by weight of Cr In a vessel equipped with at least one air hole of a double tube structure applied to the bottom blowing of (A) adding a solid carbon source to the chromium-containing molten iron in the vessel in an amount sufficient to provide a chromium-containing molten iron of at least 4.5% by weight at the end of d) (B) stirring the contents in the container by blowing a non-oxygen-based gas into it, (C) oxygen is blown into the molten iron to provide a chromium-containing molten iron in the temperature range between 1500 ° C and 1700 ° C containing at least 4.5% by weight of C and 0.15% or less by weight of Si, (D) substantially removing the slag formed in the preceding step from the vessel; (E) add de-P flux to the molten iron in the vessel, (F) stirring the contents in the container by blowing non-oxygen based gas to it to promote effective contact of the slag formed with molten iron while maintaining the concentration of iron oxide in the slag at a level of at least 1.0% by weight; (G) substantially removing the slack from the container, (H) blowing oxygen into the molten iron in the container for decarburization, blowing non-oxygen-based gas into it; (I) P is a molten iron in the temperature range of 1500 ° C to 1700 ° C by oxygen blowing while adjusting the carbon content of the molten iron to 4.5% or more by weight and the silicon content to 0.15% or less by weight until the desired level is reached. A method for producing chromium-containing steel, characterized in that it has a step of repeating the cycle of the step e, bar, and the matter between the continuous cycle of raising the temperature of. The flux for deplating according to claim 5 is 30-80% by weight of at least one compound selected from fluorides and chlorides of metals with alkali, and 0.4-30% by weight of at least one compound selected from lithium oxides and lithium salts. And 5-50% by weight of at least one compound selected from nickel oxide and 0-40% by weight of at least one compound selected from oxides and carbonates of metals with alkalis. 6. The molten iron according to claim 5, wherein the molten iron is performed with an oxidative heating element added thereto in at least one intermediate step of raising the temperature of the molten iron. 6. The process of claim 5, wherein at least the final portion of step bar is performed while maintaining oxygen concentration in the slack at a level of at least 1.0% by weight while blowing oxygen into the contents of the vessel. The flux for deamination according to claim 8 is 30-80% by weight of at least one compound selected from fluorides and chlorides of metals with alkali, 0.4-30% by weight of at least one compound selected from lithium oxide and lithium carbonate, 5-50% by weight of at least one compound selected from oxynitride and nickel oxide and oxidation of metal with alkali and 0-40% by weight of at least one compound selected from carbonates. ※ Note: This is to be disclosed based on the first application.