Method for producing alloy steel

Patent metadata

Field	Value
Publication number	US-2019211425-A1
Application number	US-201616328906-A
Country	US
Kind code	A1
Filing date	Dec 16, 2016
Priority date	Aug 29, 2016
Publication date	Jul 11, 2019
Grant date	—

Abstract

Provided is a method for producing alloy steel, the method comprising producing first alloy steel in a temperature holding furnace; maintaining the first alloy steel at a temperature of no lower than a melting point in the temperature holding furnace; and producing second alloy steel having an alloy content lower than the alloy content in the first alloy steel by melt mixing of the first alloy steel and molten steel. In the producing of the alloy steel, melting and storing of the ferroalloy are continuously performed, and thus, the temperature drop of the ferroalloy may be suppressed or prevented.

First claim

1 . A method for producing alloy steel, the method comprising:
producing first alloy steel in a temperature holding furnace; maintaining the first alloy steel at a temperature of no lower than a melting point in the temperature holding furnace; and producing second alloy steel having an alloy content lower than an alloy content in the first alloy steel by mixing the first alloy steel and molten steel.

2 . (canceled)

3 . (canceled)

4 . (canceled)

5 . The method of claim 1 , wherein the maintaining of the first alloy steel at a temperature of no lower than the melting point comprises raising the alloy content in the first alloy steel by performing at least once the adding of a ferroalloy and a molten ferroalloy into the first alloy steel.

6 . The method of claim 5 , wherein the maintaining of the first alloy steel at a temperature of no lower than the melting point comprises further charging molten steel into the temperature holding furnace.

7 . The method of claim 6 , wherein in the maintaining of the first alloy steel at a temperature of no lower than the melting point, the alloy content in the first alloy steel is controlled to be greater than approximately 25 wt % and no greater than approximately 50 wt %.

8 . The method of claim 7 , wherein at least anyone of the producing of the first alloy steel and the maintaining of the first alloy steel at a temperature of no lower than the melting point comprises supplying the temperature holding furnace with a heat source.

9 . The method of claim 8 , wherein
the producing of the second alloy steel comprises mixing fourth alloy steel which is produced by adding, into the second molten steel, at least any one of a ferroalloy and a molten ferroalloy in the tapping of the completely refined second molten steel, and an alloy content in the fourth alloy steel is lower than the alloy content in the first alloy steel.

10 . The method of claim 9 , wherein the producing of the first alloy steel in the temperature holding furnace comprises:
charging first molten steel in the temperature holding furnace; and adding at least any one of a ferroalloy and a molten ferroalloy into the first molten steel.

11 . The method of claim 10 , wherein
the charging of the first molten steel into the temperature holding furnace comprises introducing, into the temperature holding furnace, slag to be positioned on a melt surface of the first molten steel, and in the maintaining of the first alloy steel at a temperature of no lower than the melting point, a slag layer is formed on the melt surface of the first alloy steel by using the slag.

12 . The method of claim 9 , wherein the producing of the first alloy steel in the temperature holding furnace comprises:
tapping completely refined first molten steel; adding, into the first molten steel, at least any one of a ferroalloy and a molten ferroalloy and producing third alloy steel; charging the third alloy steel into the temperature holding furnace; and adding, into the third alloy steel, at least any one of a ferroalloy and a molten ferroalloy and producing first alloy steel having an alloy content more than an alloy content in the third alloy steel.

Assignees

• Posco

Inventors

• Han Woong Hee
• Ahn Chong Tae
• Kang Soo Chang
• Beak Jun Jeong
• Song Min Ho

Classifications

• C21C7/076

  Use of slags or fluxes as treating agents (C21C7/06, C21C7/064, C21C7/068 take precedence) · CPC title

• C22C33/08

  Making cast-iron alloys · CPC title

• C22C38/04

  containing manganese · CPC title

• C22C33/04 Primary

  by melting · CPC title

• C22C1/02

  by melting {(C22C1/1036 takes precedence)} · CPC title