Carburizer and carburization method using the same

Patent metadata

Field	Value
Publication number	US-2021404047-A1
Application number	US-201917293053-A
Country	US
Kind code	A1
Filing date	Dec 6, 2019
Priority date	Dec 7, 2018
Publication date	Dec 30, 2021
Grant date	—

Abstract

A carburizer, which effects carburization with respect to molten iron accommodated in an electric furnace or a ladle, includes a mixture of quicklime and a carbon material having an ash content of from 5 mass % to 18 mass %, and satisfies the conditions 0.6≤(mc+Mc)/ms≤2.7 and 0.7≤(mc+Mc)/ma≤6.5. A method of carburization uses this carburizer. Here, mc represents the mass of CaO in the carbon material, ms represents the mass of SiO2 in the carbon material, ma represents the mass of Al2O3 in the carbon material, and Mc represents the mass of the quicklime.

First claim

1 . A carburizer that effects carburization with respect to molten iron accommodated in an electric furnace or a ladle, the carburizer comprising a mixture of quicklime and a carbon material having an ash content of from 5 mass % to 18 mass %, and the carburizer satisfying conditions stipulated in the following Formula (1) and Formula (2):
0.6≤( mc+Mc )/ ms≤ 2.7  Formula (1):
0.7≤( mc+Mc )/ ma≤ 6.5  Formula (2):
wherein, in Formula (1) and Formula (2), mc represents a mass of CaO in the carbon material, ms represents a mass of SiO 2 in the carbon material, ma represents a mass of Al 2 O 3 in the carbon material, and Mc represents a mass of the quicklime.

2 . The carburizer recited in claim 1 , wherein the mixture satisfies conditions stipulated in the following Formula (1A) and Formula (2A):
0.6≤( mc+Mc )/ ms≤ 1.9  Formula (1A):
0.7≤( mc+Mc )/ ma≤ 5.0.  Formula (2A):

3 . A method of carburization using the carburizer recited in claim 1 , the method comprising, in the electric furnace or the ladle, performing carburization by adding the carburizer to a molten iron surface formed by blowing in a gas and agitating the molten iron.

4 . The method of carburization recited in claim 3 , wherein the carburizer is added by being fed towards the molten iron surface from a lance.

5 . A method of carburization using the carburizer recited in claim 2 , the method comprising, in the electric furnace or the ladle, performing carburization by adding the carburizer to a molten iron surface formed by blowing in a gas and agitating the molten iron.

6 . The method of carburization recited in claim 5 , wherein the carburizer is added by being fed towards the molten iron surface from a lance.

Assignees

• Nippon Steel Corp

Inventors

• Muneoka Hitoshi
• Asahara Norifumi
• Sakamoto Motohiro
• Yamazaki Tsuyoshi

Classifications

• C21C5/52

  Manufacture of steel in electric furnaces {(C21C5/005 takes precedence)} · CPC title

• C23C8/66

  of ferrous surfaces · CPC title

• C23C8/22 Primary

  of ferrous surfaces · CPC title

• C23C8/80

  After-treatment · CPC title

• C23C8/02 Primary

  Pretreatment of the material to be coated (C23C8/04 takes precedence) · CPC title