Surface coating for tuyeres of blast furnace and method for preparing the same

Abstract

The invention provides a composite surface coating for blast furnace tuyere and a preparation method thereof. The composite surface coating for blast furnace tuyere is composed of a bottom layer, a transition layer and a surface layer; wherein the bottom layer is made by Ni-based alloy material by plasma surfacing technique; the transition layer is made by NiCrAl alloy material by supersonic speed flame plating technique; the surface layer is made by mixture of ZrO2Y2O3 and Al2O3 by plasma spraying technique. As the composite surface coating is adopted for surface treatment of the blast furnace tuyere, the gradient change of linear expansibility between the coating and copper parent metal is realized; and the wearing resistance and thermal shock resistance of the blast furnace tuyere are ensured; pitting resistance is improved, the service life of the blast furnace tuyere is prolonged, the requirement of optimizing maintaining model of the blast furnace is met, stable and smooth production of the blast furnace is ensured, and equipment maintenance cost is greatly reduced.

Description

technical field

[0001] The invention relates to surface treatment engineering, in particular, the invention relates to a composite coating used on the surface of blast furnace tuyeres and a preparation method thereof. Background technique

[0002] The existing blast furnace tuyere bodies are all made of pure copper higher than 99.5%, and the surface wear-resistant treatment methods are mainly surfacing and spraying.

[0003] The blast furnace tuyere adopts surfacing welding process for surface treatment. The surfacing layer has high hardness and good wear resistance. At the same time, a metallurgical bond is formed between the surfacing layer and the tuyere body. The bonding strength is high, and its thermal shock resistance has been improved. Greater improvement and improvement. Since the current tuyere surfacing process is argon arc welding with nickel-based electrodes, although the characteristics of good wettability and easy surfacing of nickel-based materials and coppe...

Examples

Embodiment 1

[0019] As shown in Figure 1 and Figure 2, after the blast furnace tuyere body 1 (containing >99.5% pure copper) is manufactured, the surface of the tuyere is strengthened with a composite coating 2, and the composite coating 2 is designed to be three layers: the bottom layer 3 , transition layer 4 and surface layer 5. The base layer 3 is Ni-based alloy material, which is prepared by plasma surfacing welding process, and the thickness of surfacing welding is 2mm; the transition layer 4 is NiCrAl alloy material, which is prepared by supersonic flame spraying process, and the spraying thickness is 0.15mm; the surface layer 5 is ZrO 2 .Y 2 o 3 :Al 2 o 3 =2:3 ceramic material, prepared by plasma spraying process, spraying thickness is 0.3mm.

Embodiment 2

[0021] Implementation method is the same as embodiment 1, wherein the surfacing thickness of the bottom layer 3 is 2.5mm, the spraying thickness of the transition layer 4 is 0.1mm, and ZrO in the surface layer 5 2 .Y 2 o 3 :Al 2 o 3 = 1:1, spraying thickness is 0.4mm,

Embodiment 3

[0023] Implementation method is the same as embodiment 1, wherein the surfacing thickness of bottom layer 3 is 2mm, the spraying thickness of transition layer 4 is 0.1mm, ZrO in surface layer 5 2 .Y 2 o 3 :Al 2 o 3 =3:2, the spraying thickness is 0.5mm.

technical field

[0001] The invention relates to surface treatment engineering, in particular, the invention relates to a composite coating used on the surface of blast furnace tuyeres and a preparation method thereof. Background technique

[0002] The existing blast furnace tuyere bodies are all made of pure copper higher than 99.5%, and the surface wear-resistant treatment methods are mainly surfacing and spraying.

[0003] The blast furnace tuyere adopts surfacing welding process for surface treatment. The surfacing layer has high hardness and good wear resistance. At the same time, a metallurgical bond is formed between the surfacing layer and the tuyere body. The bonding strength is high, and its thermal shock resistance has been improved. Greater improvement and improvement. Since the current tuyere surfacing process is argon arc welding with nickel-based electrodes, although the characteristics of good wettability and easy surfacing of nickel-based materials and coppe...

Examples

Embodiment 1

[0019] As shown in Figure 1 and Figure 2, after the blast furnace tuyere body 1 (containing >99.5% pure copper) is manufactured, the surface of the tuyere is strengthened with a composite coating 2, and the composite coating 2 is designed to be three layers: the bottom layer 3 , transition layer 4 and surface layer 5. The base layer 3 is Ni-based alloy material, which is prepared by plasma surfacing welding process, and the thickness of surfacing welding is 2mm; the transition layer 4 is NiCrAl alloy material, which is prepared by supersonic flame spraying process, and the spraying thickness is 0.15mm; the surface layer 5 is ZrO 2 .Y 2 o 3 :Al 2 o 3 =2:3 ceramic material, prepared by plasma spraying process, spraying thickness is 0.3mm.

Embodiment 2

[0021] Implementation method is the same as embodiment 1, wherein the surfacing thickness of the bottom layer 3 is 2.5mm, the spraying thickness of the transition layer 4 is 0.1mm, and ZrO in the surface layer 5 2 .Y 2 o 3 :Al 2 o 3 = 1:1, spraying thickness is 0.4mm,

Embodiment 3

[0023] Implementation method is the same as embodiment 1, wherein the surfacing thickness of bottom layer 3 is 2mm, the spraying thickness of transition layer 4 is 0.1mm, ZrO in surface layer 5 2 .Y 2 o 3 :Al 2 o 3 =3:2, the spraying thickness is 0.5mm.

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