A method for preparing a tuyere sleeve with in-situ synthesized multi-gradient nickel-based cladding layer

Abstract

The invention discloses a method for preparing a tuyere sleeve with an in-situ synthesized multi-gradient nickel-based cladding layer, comprising the steps of: fully mixing a precursor material A, a precursor material B and a nickel-based alloy powder material, and cladding the mixed powder on a copper substrate of the tuyere sleeve by plasma cladding to obtain an in-situ synthesized multi-gradient cladding layer; the multi-gradient nickel-based cladding layer comprises one or more ceramic phases M in a gradient arrangement in the cladding layer generated in-situ by the reaction between the precursor material A and the precursor material B. x C y .

Description

Technical Field

[0001] The invention relates to the field of metallurgical equipment, and in particular to a method for preparing a tuyere sleeve with an in-situ synthesized multi-gradient nickel-based cladding layer. Background Art

[0002] Copper is widely used in electrical, metallurgical, mechanical equipment, and aerospace fields due to its excellent electrical and thermal conductivity. For example, in the metallurgical industry, the tuyere sleeve used in the iron-making blast furnace is made of copper. The working environment of the tuyere sleeve is extremely complex and harsh, and it must withstand coke wear, high-temperature slag iron melt erosion, and high-speed coal powder scouring. Therefore, the tuyere sleeve is often replaced due to failure, and the main failure forms are wear failure and melting failure. Once the blast furnace is stopped, it directly affects the production efficiency and causes significant economic losses. At present, cladding a nickel-based alloy layer on the surface of copper is the main means to improve the surface performance of copper. However, the nickel-based alloy protective layer does not have an anti-melting effect, because both Fe and Ni are face-centered cubic structures and can form a diffuse solid solution. At present, the surface protective cladding layer for solving the melting failure of the tuyere sleeve has not been systematically studied. Therefore, while improving the wear resistance of the copper surface, it is more important to enhance its surface anti-melting property for the surface protection of copper materials.

[0003] Ceramic materials have high hardness, high temperature resistance, corrosion resistance, and are not wettable with metals. Therefore, they are important materials for preparing anti-melting coatings. However, due to the non-wetting properties of ceramic materials and metals, the application of ceramic materials on copper tuyere sleeves has become a major problem. The breakthrough point of applying ceramic materials to the copper metal surface is how to establish a reliable connection between ceramic materials and copper while avoiding stress concentration and poor thermal conductivity. Therefore, it is necessary to seek a new protective material that can connect ceramics to the copper surface to enhance the surface properties of copper. Summary of the invention

[0004] To achieve the above object, the present invention provides a method for preparing a tuyere sleeve with an in-situ synthesized multi-gradient nickel-based cladding layer, comprising the steps of: fully mixing a precursor material A, a precursor material B and a nickel-based alloy powder material, and cladding the mixed powder on a copper substrate of the tuyere sleeve by plasma cladding to obtain an in-situ synthesized multi-gradient cladding layer; the multi-gradient nickel-based cladding layer comprises one or more ceramic phases M in a gradient arrangement in the cladding layer generated in situ by the reaction between the precursor material A and the precursor material B. x C y .

[0005] Furthermore, the parameters of plasma cladding are: substrate preheating temperature 600-800°C, cladding current 140-180A, welding gun moving speed 100-160mm / min, and powder feeding amount 20-50g / min.

[0006] Furthermore, the mixed powder includes: 5% to 20% wt of precursor material A with a particle size of 45-100 μm; 1% to 5% wt of precursor material B with a particle size of 45-100 μm; and the rest is nickel-based alloy powder with a particle size of 45-100 μm.

[0007] Furthermore, the precursor material A is selected from alloy powder containing a metal element M, where M is one or more of tungsten, titanium, silicon, iron and chromium.

[0008] Furthermore, the precursor material B is a powder containing carbon element.

[0009] Furthermore, the surface of the cladding layer is a dense oxide film synthesized in situ, and the oxide film includes an oxide of the M metal or a mixture of its oxides.

[0010] Furthermore, the precursor material A is 70TiFe, and the precursor material B is Cr 3 C 2 .

[0011] Furthermore, the method also includes the steps of vertically placing the tuyere sleeve after plasma cladding into a funnel-type pressing roller device for surface physical treatment, wherein the funnel-type pressing roller device comprises four pressing rollers symmetrically arranged outside the tuyere sleeve, and the four pressing rollers are all inclined and longitudinally arranged in parallel with the outer contour of the tuyere sleeve, so that when the tuyere sleeve is placed in the funnel-type pressing roller device, the four pressing rollers constitute a support frame of the tuyere sleeve, and under the dead weight of the tuyere sleeve, the four pressing rollers are pressed tightly against the outer surface of the tuyere sleeve, and the tuyere sleeve or the pressing rollers are rotated to perform surface physical treatment on the cladding layer of the tuyere sleeve.

[0012] Through the above technical solution, by adjusting the ratio of the mixed cladding powder, controlling the plasma cladding process parameters and physically treating the cladding layer surface, a continuous transition cladding layer material connecting the ceramic and copper substrate can be finally obtained. The new material has a continuous and complete surface, a continuous transition of the microstructure and a good interface connection, and has high resistance to melting and excellent wear resistance.

[0013] The concept, specific structure and technical effects of the present invention will be further described below in conjunction with the accompanying drawings to fully understand the purpose, characteristics and effects of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 It is the scanning electron microscope morphology of the cladding layer;

[0015] Figure 2 This is a schematic diagram of the front view of the surface treatment process of the tuyere sleeve;

[0016] Figure 3 This is a top view schematic diagram of the surface treatment process of the tuyere sleeve;

[0017] Figure 4 It is the X-ray diffraction analysis spectrum of the cladding layer;

[0018] Figure 5 This is the surface morphology of the cladding layer after friction and wear test;

[0019] Figure 6 This is the morphology of the cladding layer after the melting loss experiment. DETAILED DESCRIPTION

[0020] The following describes several preferred embodiments of the present invention with reference to the drawings in the specification, so that the technical content is clearer and easier to understand. The present invention can be embodied in many different forms of embodiments, and the protection scope of the present invention is not limited to the embodiments mentioned in the text.

[0021] Example 1

[0022] A method for preparing an in-situ synthesized multi-gradient nickel-based cladding layer on a copper surface comprises the following steps:

[0023] 15wt.% of precursor material A, 5wt.% of precursor material B and Ni60A self-fluxing alloy powder are weighed and prepared according to the proportion. Among them, the precursor material A is 70TiFe, and the precursor material B is Cr 3 C 2 , all alloy powder particle size range is between 45-100μm. Put the prepared powder into the mixing mixer and mix it thoroughly for 48h. After mixing evenly, put it into the 80℃ oven to dry for 2h. After drying, put the dried powder into the plasma cladding powder feeder.

[0024] Grind the copper substrate with 400-grit sandpaper to remove surface oxide scale and oil impurities, and place it on the cladding machine table.

[0025] Plasma cladding: Place the copper in the induction coil and heat the copper substrate by energizing the induction coil. At the same time, use an infrared thermometer to measure the preheating temperature of the substrate so that the preheating temperature can be controlled. After the copper is heated to the preheating temperature, plasma cladding is started on the copper surface. The cladding parameters used are: argon is used as the protective gas, the substrate preheating temperature is 750℃, the cladding current is 160A, the welding gun moving speed is 120mm / min, and the powder feeding amount is 30g / min.

[0026] The multi-gradient nickel-based cladding layer obtained in Example 1 was cut by wire cutting, and its microstructure was observed by a scanning electron microscope (Nova Nano SEM 450) with an energy dispersive spectrometer. The microstructure of the multi-gradient cladding layer in Example 1 is as follows: Figure 1 As shown. A metal oxide film was successfully synthesized in situ on the surface of the multi-gradient cladding layer, and the thickness of the oxide layer was about 4μm. After point scanning analysis by the energy dispersive spectrometer of the scanning electron microscope, the composition of the surface oxide layer was analyzed to be (Fe 2 O 3 ) x +(FeO) y and Ti 2 O 3 .Ti 2 O 3 The oxide layer is dense and grows along the nickel substrate surface; while the iron oxide (Fe 2 O 3 ) x +(FeO) y Relatively loose, growing on Ti 2 O 3 A variety of reinforcing phases are generated in situ inside the cladding layer. Through point scanning and surface scanning analysis of the energy spectrometer, the cladding layer is composed of precursor materials TiFe and Cr 3 C 2 Dark block-shaped TiC ceramic particles reinforced by in-situ synthesis and Cr generated by Ni60A self-fluxing powder cladding 23 C 6 It is composed of CrB reinforcing phase and Ni-based solid solution.

[0027] In order not to destroy (Fe 2 O 3 ) x +(FeO) y On the premise of forming an oxide layer, the layer is made denser to further improve the anti-wetting property of the surface of the tuyere sleeve. The tuyere sleeve 1 after plasma cladding is vertically placed in a funnel-type roller device for surface physical treatment. Figure 2 , 3 As shown, the funnel-type roller device includes four rollers 2 symmetrically arranged outside the tuyere sleeve. The four rollers 2 are all inclined and arranged longitudinally, parallel to the outer contour of the tuyere sleeve, so that when the tuyere sleeve is placed in the funnel-type roller device, the four rollers 2 form a support frame for the tuyere sleeve, and under the deadweight G of the tuyere sleeve 1, the four rollers are close to the outer surface of the tuyere sleeve. When the tuyere sleeve 1 or the rollers 2 are rotated, the reaction force F generated by the four rollers 2 supporting the weight G of the tuyere sleeve 1 rolls the cladding layer on the outer surface of the tuyere sleeve, thereby preventing wear and damage (Fe 2 O 3 ) x +(FeO)y The oxide layer can be compacted by rolling the relatively loose layer, thereby further improving the anti-wetting performance of the tuyere small sleeve cladding layer to the molten iron, and also can improve its wear resistance to a certain extent.

[0028] The phase composition of the cladding layer was analyzed by X-ray diffractometer (Burker-AXS D8 Advance), using a Cu target Kα radiation source, the working voltage of the ray tube was 50 kV, the diffraction angle range was 10° to 90°, and the scanning speed was 2° / min. Figure 4 The surface is mainly composed of metal oxide ceramic phase, which is composed of Fe 2 O 3 , FeO and Ti 2 O 3 The main peak of γ-(Cu,Fe,Ni) solid solution is also detected. Inside the cladding layer, the main peak of γ-(Cu,Fe,Ni) solid solution is more prominent, indicating that there are more γ-(Cu,Fe,Ni) solid solution inside the cladding layer, and the strengthening phase is also detected.

[0029] The morphology after friction and wear test is as follows Figure 5 As shown. It can be seen that the worn surface is relatively smooth, containing only some pear grooves and a small amount of wear debris, which is a typical abrasive wear mechanism. At the same time, we also conducted friction and wear experiments on the copper substrate. The copper wear surface has obvious peeling pits and plastic deformation areas, which is a typical adhesive wear mechanism. The wear weight loss of copper and cladding layer is about 15.6mg and 1.2mg respectively. It can be seen that the in-situ synthesized multi-gradient cladding layer improves the wear resistance of copper by 13 times and has excellent wear resistance.

[0030] After the melting loss test, the surface Figure 6 As shown. The iron block heated by the plasma arc melts and drips, and then solidifies and falls off after dripping on the surface of the cladding layer heated to 600°C. The falling of the iron block indicates that when the molten iron drips on the surface of the cladding layer, there is no mutual diffusion between elements, thus causing corrosion to the cladding layer. This is because there is a relatively dense metal oxide film on the surface of the cladding layer, and the molten iron does not wet this ceramic oxide film. Therefore, the in-situ synthesized multi-gradient cladding layer has excellent anti-melting effect.

[0031] Based on the above analysis and test results, the nickel-based cladding layer of the present invention generates a metal oxide ceramic film in situ on the surface, and its composition is (Fe 2 O 3 ) x +(FeO) y and Ti 2 O 3 Dark block ceramic particles TiC, block CrB and strip Cr appeared in the cladding layer.23 C 6 The reinforcement phase has a more fine and uniform structure and is well combined with the nickel-based solid solution. The reinforcement phase acts as a load-bearing area in friction and wear, and has a certain uniform load and anti-wear effect. This multi-gradient nickel-based cladding layer of oxide ceramic film-ceramic particle reinforced nickel-based cladding layer has excellent melting resistance and wear resistance.

[0032] The preferred specific embodiments of the present invention are described in detail above. It should be understood that ordinary technicians in the field can make many modifications and changes based on the concept of the present invention without creative work. Therefore, all technical solutions that can be obtained by technicians in the technical field based on the concept of the present invention through logical analysis, reasoning or limited experiments on the basis of the prior art should be within the scope of protection determined by the claims.

Claims

1. A method for preparing a tuyere sleeve with an in-situ synthesized multi-gradient nickel-based cladding layer, It is characterized in that Includes steps: After the precursor material A, the precursor material B and the nickel-based alloy powder material are fully mixed, the mixed powder is clad on the copper substrate of the tuyere sleeve by plasma cladding to obtain an in-situ synthesized multi-gradient cladding layer; the multi-gradient nickel-based cladding layer includes one or more ceramic phases M in a gradient arrangement in the cladding layer generated in situ by the reaction between the precursor material A and the precursor material B. x C y ; The method also includes the steps of vertically placing the tuyere sleeve after plasma cladding into a funnel-type pressing roller device for surface physical treatment, wherein the funnel-type pressing roller device comprises four pressing rollers symmetrically arranged outside the tuyere sleeve, wherein the four pressing rollers are all inclined and longitudinally arranged in parallel with the outer contour of the tuyere sleeve, so that when the tuyere sleeve is placed in the funnel-type pressing roller device, the four pressing rollers constitute a support frame of the tuyere sleeve, and under the dead weight of the tuyere sleeve, the four pressing rollers are pressed tightly against the outer surface of the tuyere sleeve, and the tuyere sleeve or the pressing rollers are rotated to perform surface physical treatment on the cladding layer of the tuyere sleeve.

2. The method for preparing a tuyere sleeve with an in-situ synthesized multi-gradient nickel-based cladding layer according to claim 1, in, The parameters of plasma cladding are: substrate preheating temperature 600~800℃, cladding current 140~180A, welding gun moving speed 100~160mm / min, and powder feeding amount 20~50g / min.

3. The method for preparing a tuyere sleeve with an in-situ synthesized multi-gradient nickel-based cladding layer according to claim 1, in, The mixed powder includes: 5% to 20% wt of precursor material A with a particle size of 45-100 μm; 1% to 5% wt of precursor material B with a particle size of 45-100 μm; and the rest is nickel-based alloy powder with a particle size of 45-100 μm.

4. The method for preparing a tuyere sleeve with an in-situ synthesized multi-gradient nickel-based cladding layer according to claim 1, in, The precursor material A is an alloy powder containing a metal element M, where M is one or more of tungsten, titanium, silicon, iron and chromium.

5. The method for preparing a tuyere sleeve with an in-situ synthesized multi-gradient nickel-based cladding layer according to claim 1, in, The precursor material B is powder containing carbon element.

6. The method for preparing a tuyere sleeve with an in-situ synthesized multi-gradient nickel-based cladding layer according to claim 1, in, The surface of the cladding layer is a dense oxide film synthesized in situ, and the oxide film includes the oxide of the M metal or a mixture of its oxides.

7. The method for preparing a tuyere sleeve with an in-situ synthesized multi-gradient nickel-based cladding layer according to claim 4, in, Precursor material A is 70TiFe, and precursor material B is Cr 3 C 2 .

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