Laser cladding wear-resistant and high-temperature-resistant material for crystallizer

Abstract

The invention discloses a crystallizer laser cladding wear-resistant and high-temperature-resistant material which comprises the following components in percentage by mass: 2.3%-3.6% of Co powder, 4%-4.8% of WC powder, 7%-8.2% of Cr powder, 1.5%-1.9% of Fe powder, 0.5%-0.55% of C powder, 2.6%-2.8% of Ni powder coated with TiN, 4.6%-5.2% of SiC powder coated with Ni-P alloy and the balance of Ni powder, according to the scheme, new-form Ni-P alloy coated SiC powder and TiN coated Ni powder are mixed and matched with Co, WC, Cr and other components in a limited proportion to form the composite powder for laser cladding, an alloy layer formed after laser cladding is excellent in wear resistance, high temperature resistance and other performance, and the composite powder takes microalloying as the standard, so that the composite powder has the advantages of high mechanical strength, high mechanical strength and the like. And the addition mode of trace or small amounts of components is beneficial for reducing the cost.

Description

Technical Field

[0001] This invention relates to the field of surface hardening technology, specifically to wear-resistant and high-temperature resistant materials for crystallizer laser cladding. Background Technology

[0002] The crystallizer is a key component of continuous casting equipment, and its performance and operational reliability directly affect continuous casting productivity and billet quality. With the development of high-speed casting, the service life of crystallizers cannot meet the requirements, leading to increased maintenance costs. Currently, common measures to improve crystallizer life are to improve the forming materials of the crystallizer, such as Ag-Cu and Cu-Fe quaternary alloy materials, but these still cannot meet the requirements in terms of wear resistance.

[0003] In response, surface strengthening technology has emerged in the market. This technology uses methods such as laser cladding to solidify a multi-component alloy layer onto the surface of the crystallizer. To meet the requirements for wear resistance, common cladding materials include Ni-based cladding materials, which are based on Ni and have added components such as Cr, Co, and SiC to improve performance. The disadvantage is that the amount of these reinforcing components added is relatively large, which increases the cost.

[0004] In response, some researchers have improved the morphology of powders, such as TiN-coated Ni powder and Ni-P alloy-coated SiC powder. However, there are currently few publicly available technologies for the combined use of such multi-morphological powders and their miniaturized applications. Our company has initiated a research and development project to address this issue. Summary of the Invention

[0005] To address at least one of the aforementioned technical deficiencies, the present invention provides the following technical solution:

[0006] This application discloses a wear-resistant and high-temperature resistant material for laser cladding of crystallizers, which, by mass, comprises the following components: 2.3-3.6% Co powder, 4-4.8% WC powder, 7-8.2% Cr powder, 1.5-1.9% Fe powder, 0.5-0.55% C powder, 2.6-2.8% TiN-coated Ni powder, 4.6-5.2% Ni-P alloy-coated SiC powder, with the balance being Ni powder.

[0007] In this solution, SiC powder coated with a novel Ni-P alloy and Ni powder coated with TiN are mixed and combined with a limited proportion of Co, WC, Cr and other components to form a composite powder for laser cladding. The alloy layer formed after laser cladding exhibits excellent wear resistance and high temperature resistance. This composite powder is based on micro-alloying, and the addition of trace or small amounts of components helps to reduce costs.

[0008] Furthermore, the TiN-coated Ni powder is prepared as follows: TiN and Ni are mixed at a mass ratio of 3-4:82-86 and then ball-milled at high energy.

[0009] Furthermore, the SiC powder coated with Ni-P alloy is prepared as follows: Plating solution is prepared with: nickel sulfate 20-40 g / L, sodium hypophosphite 10-30 g / L, citric acid 10-30 g / L, sodium acetate 5-25 g / L, potassium iodate 0.01-0.05 mg / L, and sodium dodecylbenzenesulfonate 0.01-0.05 mg / L;

[0010] SiC powder is placed in a heated plating solution until the solution boils. The temperature of the plating solution is 80-90℃. The solution is activated by using a glass rod coated with Ni-P alloy.

[0011] Solid-liquid separation and drying yielded Ni-P alloy-coated SiC powder.

[0012] Furthermore, the laser cladding parameters are as follows: scanning speed of 5-15 mm / s, wavelength of 900-1000 nm, overlap rate of 30-50%, and 2-4 cladding layers. Optimizing the cladding parameters helps improve the performance of the alloy layer.

[0013] Furthermore, preheating the workpiece to 300-330℃ before laser cladding helps the alloy layer to bond better with the workpiece surface.

[0014] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0015] 1. The preferred component formulation of this invention combines novel particle forms with preferred and limited components, resulting in excellent performance of the alloy layer in terms of wear resistance and high temperature resistance when added in trace amounts or small quantities, which helps to reduce costs. Detailed Implementation

[0016] The present invention will be further described below with reference to specific embodiments.

[0017] The TiN-coated Ni powder is prepared as follows: TiN and Ni are mixed in a mass ratio of 3-4:82-86 and then ball-milled at high energy. For details, please refer to the patent document with application publication number CN115058627A.

[0018] In the following preparation example, the TiN-coated Ni powder was prepared as follows: TiN and Ni were mixed at a mass ratio of 3:85 and ball-milled at high energy for 6 hours.

[0019] For details on the preparation of Ni-P alloy-coated SiC powder, please refer to the patent document CN104694911 B.

[0020] In the following preparation examples, the preparation of Ni-P alloy-coated SiC powder is as follows:

[0021] First, prepare the plating solution: nickel sulfate 37g / L, sodium hypophosphite 22g / L, citric acid 18g / L, sodium acetate 20g / L, potassium iodate 0.03mg / L, sodium dodecylbenzenesulfonate 0.04mg / L, and adjust the pH to 5 with ammonia.

[0022] Second, preheat the plating solution to 85°C.

[0023] Third, add SiC powder, which accounts for about 1 / 20 of the mass of the plating solution, to the preheated plating solution and activate it with a glass rod coated with Ni-P alloy until the plating solution churns, which takes about 4 hours.

[0024] Fourth, solid-liquid separation is performed by filtration, and the filtered particles are dried to obtain Ni-P alloy-coated SiC powder.

[0025] Commercially available products are used for Co powder, WC powder, Cr powder, etc.

[0026] Example 1

[0027] The cladding alloy layer is prepared as follows:

[0028] The following components are mixed by weight: 2.5% Co powder, 4.2% WC powder, 7.5% Cr powder, 1.6% Fe powder, 0.52% C powder, 2.6% TiN-coated Ni powder, 4.9% Ni-P alloy-coated SiC powder, and the balance being Ni powder.

[0029] The substrate to be coated is preheated to a temperature of 310℃.

[0030] The mixed powder is clad in a laser to form a three-layer coating on the substrate surface, with a total thickness of about 3 mm. The laser cladding parameters are: laser power of 3 kW, scanning speed of 10 mm / s, wavelength of 900 nm, laser spot diameter of 8 mm, powder feeding rate of 25 g / min, and argon flow rate of 23 L / min.

[0031] Example 2

[0032] The difference from Example 1 is that the composition ratio of the mixed powder is as follows: Co powder 2.9%, WC powder 4.6%, Cr powder 7.9%, Fe powder 1.7%, C powder 0.51%, TiN-coated Ni powder 2.7%, Ni-P alloy-coated SiC powder 4.8%, and the balance is Ni powder.

[0033] Example 3

[0034] The difference from Example 1 is that the composition ratio of the mixed powder is as follows: Co powder 3.1%, WC powder 4.7%, Cr powder 8.1%, Fe powder 1.8%, C powder 0.53%, TiN-coated Ni powder 2.8%, Ni-P alloy-coated SiC powder 5.1%, and the balance is Ni powder.

[0035] Example 4

[0036] The difference from Example 1 is that the composition ratio of the mixed powder is as follows: Co powder 3.3%, WC powder 4.8%, Cr powder 8.0%, Fe powder 1.8%, C powder 0.55%, TiN-coated Ni powder 2.7%, Ni-P alloy-coated SiC powder 5.0%, and the balance is Ni powder.

[0037] Comparative Example 1

[0038] The difference from Example 1 lies in the composition ratio of the mixed powder: 2.5% Co powder, 4.2% WC powder, 7.5% Cr powder, 1.6% Fe powder, 0.52% C powder, 4.9% Ni-P alloy-coated SiC powder, and the balance being Ni powder.

[0039] The performance of the products prepared above was tested, as shown in Table 1:

[0040] Table 1

[0041] <![CDATA[Hardness (HV 0.2 )]]> Example 1 564 Example 2 568 Example 3 579 Example 4 570 Comparative Example 1 412

[0042] As can be seen from the table above, the micro-alloy layer scheme of this solution exhibits excellent hardness and good heat resistance. The alloy layer prepared by adding a large amount of conventional reinforcing components shows similar performance in both aspects to the product of this scheme. The principles of each component are based on conventional understanding, such as the solid solution strengthening mechanism of Cr, Fe, and Co, the combination of Ni and Fe, and the combination of Cr and Ni. As for the deeper mechanisms, they are currently unknown and our company is still continuing to explore them.

[0043] The above are merely preferred embodiments of the present invention. The scope of protection of the present invention is not limited to the above embodiments. All technical solutions falling within the scope of the present invention's concept are within the scope of protection of the present invention. It should be noted that for those skilled in the art, any improvements and modifications made without departing from the principle of the present invention should also be considered within the scope of protection of the present invention.

Claims

1. A wear-resistant and high-temperature resistant material for crystallizer laser cladding, characterized in that, By weight, it comprises the following components: 2.3-3.6% Co powder, 4-4.8% WC powder, 7-8.2% Cr powder, 1.5-1.9% Fe powder, 0.5-0.55% C powder, 2.6-2.8% TiN-coated Ni powder, 4.6-5.2% Ni-P alloy-coated SiC powder, with the balance being Ni powder.

2. The wear-resistant and high-temperature resistant material for crystallizer laser cladding as described in claim 1, characterized in that: The TiN-coated Ni powder is prepared as follows: TiN and Ni are mixed at a mass ratio of 3-4:82-86 and then ball-milled at high energy.

3. The wear-resistant and high-temperature resistant material for crystallizer laser cladding as described in claim 1, characterized in that: The preparation of Ni-P alloy-coated SiC powder is as follows: Plating solution is prepared with: nickel sulfate 20-40 g / L, sodium hypophosphite 10-30 g / L, citric acid 10-30 g / L, sodium acetate 5-25 g / L, potassium iodate 0.01-0.05 mg / L, and sodium dodecylbenzenesulfonate 0.01-0.05 mg / L. SiC powder is placed in a heated plating solution until the solution boils. The temperature of the plating solution is 80-90℃. The solution is activated by using a glass rod coated with Ni-P alloy. Solid-liquid separation and drying yielded Ni-P alloy-coated SiC powder.

4. The wear-resistant and high-temperature resistant material for crystallizer laser cladding as described in claim 1, characterized in that: The laser cladding parameters are as follows: scanning speed is 5-15 mm / s, wavelength is 900-1000 nm, overlap rate is 30-50%, and cladding layer is 2-4 layers.

5. The wear-resistant and high-temperature resistant material for crystallizer laser cladding as described in claim 4, characterized in that: The workpiece is preheated to 300-330℃ before laser cladding.