Blast-furnace tuyere

• US 4,189,130 A
• Filed: 10/19/1978
• Issued: 02/19/1980
• Est. Priority Date: 10/19/1978
• Status: Expired due to Term

• Current Assignee: TOCALO Co., Ltd.
• Original Assignee: Kawasaki Steel Corporation (JFE Holdings Incorporated), TOYO Calorizing IND Company Limited
• Inventors: Sato, Akimune, Watanabe, Hideto, Oka, Takashi, Shoji, Shigeo
• Primary Examiner(s): Andrews, M. J.
• Application Number:
  US05/952,930
• Time in Patent Office: 488 Days
• Field of Search: 266/265, 266/270
• US Class Current: 266/270
• CPC Class Codes: C21B 7/16 Tuyéres
• CPC Class Codes: C23C 4/02 Pretreatment of the material to be coated, e.g. for coating on selected surface areas
• CPC Class Codes: C23C 4/11 Oxides
• CPC Class Codes: Y10S 428/926 Thickness of individual layer specified
• CPC Class Codes: Y10T 428/1291 Next to Co-, Cu-, or Ni-base component

Abstract

A blast-furnace tuyere having excellent thermal shock resistance and high durability consists of a tuyere substrate composed of copper or copper alloy, a self-fluxing alloy metallized layer sprayed on the substrate, a cermet coating sprayed on the alloy metallized layer, and a ceramic coating sprayed on the cermet coating. The cermet coating is made from a mixture of an alloy material consisting essentially of 5 to 60 wt% of Co, 5 to 50 wt% of Ni, 5 to 25 wt% of Cr, 5 to 40 wt% of Mo, 5 to 40 wt% of W, 3 to 40 wt% of Si and inevitable impurities, and a ceramic eutectic material consisting essentially of 95 to 65 wt% of Al₂ O₃, 5 to 30 wt% of ZrO₂, 2 to 20 wt% of TiO₂, 3 to 30 wt% of SiO₂ and inevitable impurities. The ceramic coating is made from the same ceramic material as used in the formation of the cermet coating.

Claims

1. In a blast-furnace tuyere consisting of a tuyere substrate composed of copper or copper alloy, a self-fluxing alloy metallized layer sprayed on the surface of the substrate, a cermet coating sprayed on the surface of the alloy metallized layer, and a ceramic coating sprayed on the surface of the cermet coating, an improvement which comprises making the cermet coating from a mixture of an alloy material consisting essentially of 5 to 60 wt% of cobalt, 5 to 50 wt% of nickel, 5 to 25 wt% of chromium, 5 to 40 wt% of molybdenum, 5 to 40 wt% of tungsten, 3 to 40 wt% of silicon and inevitable impurities, and a ceramic material having an eutectic structure and consisting essentially of 95 to 65 wt% of Al₂ O₃, 5 to 30 wt% of ZrO₂, 2 to 20 wt% of TiO₂, 3 to 30 wt% of SiO₂ and inevitable impurities and making the ceramic coating from a ceramic material having the same composition as used in the formation of the cermet coating.

2. A blast-furnace tuyere as claimed in claim 1, wherein the alloy material for the cermet coating consists essentially of 5 to 60 wt% of cobalt, 5 to 50 wt% of nickel, 5 to 25 wt% of chromium, 5 to 40 wt% of molybdenum, 5 to 40 wt% of tungsten, 3 to 40 wt% of silicon and inevitable impurities.

3. A blast-furnace tuyere as claimed in claim 1, wherein the ceramic material for the cermet coating consists essentially of 5 to 30 wt% of ZrO₂, 65 to 95 wt% of Al₂ O₃, 2 to 20 wt% of TiO₂, 3 to 30 wt% of SiO₂ and inevitable impurities.

4. A blast-furnace tuyere as claimed in claim 1, wherein the mixture has a mixing ratio of the alloy material to the ceramic material of 3:

7 to 7;

3.

5. A blast-furnace tuyere as claimed in claim 1, wherein the cermet coating has a thickness of 50 to 250 μ

m.

6. A blast-furnace tuyere as claimed in claim 1, wherein the ceramic material for the ceramic coating consists essentially of 5 to 30 wt% of ZrO₂, 70 to 95 wt% of Al₂ O₃, 2 to 20 wt% of TiO₂, 3 to 30 wt% of SiO₂ and inevitable impurities.

7. A blast-furnace tuyere as claimed in claim 1, wherein the ceramic coating has a thickness of 100 to 300 μ

m.