Laser cladding iron-based corrosion-resistant and wear-resistant coating and preparation method thereof

Abstract

The invention belongs to the technical field of surface engineering, and particularly relates to a laser cladding iron-based corrosion-resistant and wear-resistant coating and a preparation method thereof. The invention relates to a laser cladding iron-based corrosion-resistant and wear-resistant coating which comprises the following iron-based alloy powder components in percentage by mass: 0.2-0.4% of C; 2.0 to 3.0% of B; the content of Cr is 12.0 to 16.0 percent; 0.5 to 1.0 percent of Ti; 0.5 to 1.5 percent of Si; 0.5 to 1.0 percent of Ni; 0.3 to 0.7% of Ce; s is less than 0.03%; p is less than 0.045%; and the balance of Fe. The coating has the beneficial effects that the coating takes the iron-based alloy powder as a raw material, and the iron-based alloy powder is uniformly cladded on the surface of the H13 steel by utilizing a laser directional energy deposition technology, so that a compact and uniform corrosion-wear-resistant cladding layer is formed, and the service life of the material under the working condition of erosion corrosion of molten aluminum is remarkably prolonged.

Description

Technical Field

[0001] The present invention relates to the technical field of surface engineering, and particularly relates to a laser cladding iron-based corrosion-resistant and wear-resistant coating and a preparation method thereof. Background Art

[0002] H13 steel is a hot work die steel widely used at home and abroad at present. Because of its good hot strength, red hardness, relatively high toughness and thermal fatigue resistance, it is widely used in the components of aluminum alloy die-casting machines. However, the corrosion-wear resistance of H13 steel in molten aluminum is relatively insufficient. In actual use, when the surface of the H13 steel component contacts the molten aluminum, intermetallic compounds are formed by reaction, resulting in welding on the surface of the component and a decrease in surface quality, which affects the smooth progress of production. In addition, the strength and hardness of H13 steel decrease significantly at high temperatures, which in turn leads to a decrease in its wear resistance and cannot meet the erosion-corrosion conditions of high-temperature molten aluminum. Eventually, under the interaction of high-temperature molten aluminum corrosion and erosion, the equipment components gradually fail. Since most of the failures of equipment components start from the surface, surface treatment of H13 steel components to form a continuous protective layer on the material surface to avoid direct contact between the H13 steel matrix and high-temperature molten aluminum can effectively improve the service life of equipment components.

[0003] To improve the corrosion and wear resistance of the surface of H13 steel, laser cladding technology has become an effective surface modification method because of its unique advantages. Laser cladding technology rapidly melts and solidifies the cladding material on the surface of the substrate through a high-energy density laser beam, so as to form a dense cladding layer metallurgically bonded to the substrate on the surface of the substrate. This technology can not only significantly improve the corrosion resistance and wear resistance of the material surface, but also optimize the microstructure of the coating through the rapid solidification effect and inhibit the formation of cracks.

[0004] Borides in FeCrB alloy have good high-temperature thermal stability and hardly react with molten aluminum at 600-700 °C. Therefore, it has become a potential high-corrosion-resistant material for molten aluminum and is widely used in the surface modification of large corrosion-resistant and wear-resistant parts. However, the microstructure of FeCrB alloy contains a large number of coarse plate-like primary borides and long needle-like or continuous network eutectic borides. During the laser cladding process, the heat accumulation generated by multi-pass cladding will continuously increase the internal stress of the cladding layer. The hard and brittle borides have a low tolerance to residual stress and are prone to stress concentration at the tips of the borides, resulting in the initiation and propagation of microcracks and promoting the generation of a large number of microcracks on the surface of the cladding layer. In addition, during the laser cladding process, when the FeCrB alloy powder is directly cladded on the surface of H13 steel, due to the large difference in thermal expansion coefficient between the substrate and the cladding layer and the existence of residual stress, the cladding layer is prone to cracking and even peeling, affecting its actual use effect.

[0005] In summary, to solve the above technical problems of the prior art:

[0006] The present invention provides a laser cladding iron-based corrosion-resistant and wear-resistant coating and a preparation method thereof: By improving the laser cladding process parameters and adjusting the composition of the cladding material, this invention can effectively inhibit the excessive precipitation of borides, optimize the microstructure of the cladding layer, and improve the bonding strength between the cladding layer and the H13 steel substrate.

[0007] The present invention not only provides technical support for the application of H13 steel in the high-temperature aluminum liquid corrosion-wear environment, but also has important value for expanding the application of laser cladding technology in hot work die steel. Summary of the Invention

[0008] To solve the above technical problems, the present invention provides a laser cladding iron-based corrosion-resistant and wear-resistant coating and a preparation method thereof.

[0009] This coating uses iron-based alloy powder as the raw material, and utilizes the laser directed energy deposition technology to uniformly clad the iron-based alloy powder on the surface of H13 steel to form a dense and uniform corrosion-wear resistant cladding layer, thereby significantly improving the service life of the material under the working conditions of aluminum liquid erosion corrosion.

[0010] A laser cladding iron-based corrosion-resistant and wear-resistant coating, the laser cladding iron-based corrosion-resistant and wear-resistant coating comprises the following corrosion-resistant and wear-resistant iron-based alloy powder in mass percentage:

[0011] C 0.2 - 0.4%;

[0012] B 2.0 - 3.0%;

[0013] Cr 12.0 - 16.0%;

[0014] Ti 0.5 - 1.0%;

[0015] Si 0.5 - 1.5%;

[0016] Ni 0.5 - 1.0%;

[0017] Ce 0.3 - 0.7%;

[0018] S < 0.03%;

[0019] P < 0.045%;

[0020] The balance is Fe.

[0021] As a further improvement of this solution, the particle size of the alloy powder is 53 - 150 μm.

[0022] As a further improvement of this solution, it includes the following preparation steps:

[0023] S1: Select H13 die steel as the base material, polish the surface of the base material with sandpaper to remove the oxide scale and oil stain, then clean the polished surface with absolute ethanol and dry it.

[0024] S2: Prepare iron-based alloy powder one and iron-based alloy powder two before laser cladding. Among them,

[0025] The iron-based alloy powder one is the corrosion-resistant and wear-resistant iron-based alloy powder described above;

[0026] The powder two is 316 alloy powder;

[0027] Dry the iron-based alloy powder one and the iron-based alloy powder two in an oven at 120 °C for 20 min;

[0028] S3: Use a continuous fiber laser to first clad a layer of 316 coating on the surface of the H13 die steel according to the preset laser cladding process parameters;

[0029] S4: Use a angle grinder to grind the 316 clad layer flat and remove the surface oxide scale;

[0030] S5: Use a continuous fiber laser to clad an iron-based corrosion-resistant and wear-resistant clad layer on the surface of the 316 transition layer according to the preset laser cladding process parameters.

[0031] As a further improvement of this solution,

[0032] In the step S2, the 316 alloy powder includes the following components in mass percentage:

[0033] C ≤ 0.08%;

[0034] Ni 10.0 - 14.0%,

[0035] Cr 16.0 - 19.0%;

[0036] Mo 2.0 - 3.0%;

[0037] Si ≤ 1.0%;

[0038] Mn ≤ 2.0%;

[0039] P ≤ 0.045%;

[0040] S ≤ 0.03%;

[0041] The balance is Fe.

[0042] As a further improvement of this solution,

[0043] In the step S2, the particle size of the 316 alloy powder is 53 - 150 μm.

[0044] As a further improvement of this solution, in step S3, the 316 coating cladded on the surface of the H13 substrate is a transition layer. The specific laser cladding process parameters are as follows: laser power is 2000 - 2500W, laser scanning speed is 10 - 15mm / s, powder feeding rate is 1.6 - 2.0r / min, spot diameter is 3 - 4mm, and overlapping rate is 40%.

[0045] As a further improvement of this solution, in step S3, during the laser cladding of 316, high-purity argon gas is used as the shielding gas to protect the molten pool, and the argon gas flow rate is 14 - 16L / min;

[0046] In step S3, the thickness of the obtained single-layer 316 transition layer is 1.5 - 2.5mm.

[0047] As a further improvement of this solution, in step S5, the specific laser cladding process parameters of the iron-based corrosion-resistant and wear-resistant coating are as follows: laser power is 1400 - 1600W, laser scanning speed is 8 - 10mm / s, powder feeding rate is 0.8 - 1.0r / min, spot diameter is 3 - 4mm, and overlapping rate is 40%.

[0048] As a further improvement of this solution, in step S5, during the laser cladding of the iron-based corrosion-resistant and wear-resistant coating, high-purity argon gas is used as the shielding gas to protect the molten pool, and the argon gas flow rate is 14 - 16L / min;

[0049] As a further improvement of this solution, in step S5, the thickness of the obtained iron-based corrosion-resistant and wear-resistant coating is 1.0 - 2.0mm.

[0050] The beneficial effects of the present invention are as follows:

[0051] 1) In the preparation method of the present invention: Through the laser cladding technology, a cladding layer with a total thickness of not less than 3mm is formed on the surface of the H13 die steel, and the thickness of this cladding layer can be adjusted according to requirements. Because the ductility and plasticity of the 316 cladding layer are very good, multi-layer cladding can be carried out to adjust the overall thickness of the final cladding layer.

[0052] 2) In the preparation method of the present invention: Since the hardness of both the iron-based corrosion-resistant and wear-resistant cladding material and the H13 substrate is relatively large, and the difference in their thermal expansion coefficients is relatively large, directly cladding a large area of the iron-based corrosion-resistant and wear-resistant material on the H13 substrate easily causes cracking of the substrate and the cladding layer. The present invention can well solve this problem by adding a 316 transition layer between the substrate and the iron-based corrosion-resistant and wear-resistant cladding layer. The obtained laser cladding layer has good forming, no cracks and pores, and excellent metallurgical bonding with the substrate.

[0053] (3) In the laser cladded iron-based corrosion-resistant and wear-resistant coating of the present invention:

[0054] The size of the hard and brittle borides in the laser cladding layer has been significantly refined, improving the hardness, strength, toughness and wear resistance of the cladding layer;

[0055] The in-situ formed TiC and TiB2 ceramic particles in the laser cladding layer can significantly improve the hardness and wear resistance of the cladding layer;

[0056] The borides in the cladding layer separate the iron matrix into small unit cells, effectively isolating the contact between the aluminum liquid and the iron matrix, and significantly improving the corrosion resistance of the cladding layer to aluminum liquid. Description of the Drawings

[0057] Figure 1 It is a cross-sectional view of the laser cladding layer in Example 1 of the present invention;

[0058] Figure 2 It is a microstructural diagram of the iron-based corrosion-resistant and wear-resistant coating in the laser cladding layer in Example 1 of the present invention. Detailed Description of the Invention

[0059] The embodiments of the present invention will be described in detail below. The embodiments described below with reference to the drawings are exemplary and are only used to explain the present invention and should not be construed as a limitation to the present invention.

[0060] Example 1

[0061] A laser cladding iron-based corrosion-resistant and wear-resistant coating and its preparation method. The composition of the iron-based corrosion-resistant and wear-resistant cladding powder used is as follows:

[0062] 0.3wt% C, 2.5wt% B, 14.0wt% Cr, 1.0wt% Si, 0.7wt% Ti, 0.7wt% Ni, 0.5wt% Ce, S < 0.03%, P < 0.045%, and the balance is iron.

[0063] The composition of the commercially available 316 alloy powder used for the transition layer is as follows:

[0064] 0.05wt% C, 12.0wt% Ni, 18.0wt% Cr, 2.0wt% Mo, 1.0wt% Si, 1.0wt% Mn, P ≤ 0.045%, S ≤ 0.03%, and the balance is Fe.

[0065] The laser cladding iron-based corrosion-resistant and wear-resistant coating is prepared according to the following steps:

[0066] S1. The surface of the H13 die steel is polished with 240# sandpaper to remove the surface oxides and used as the substrate, and then the surface oil stain is cleaned with anhydrous ethanol and dried;

[0067] S2: Dry the prepared iron-based corrosion- and wear-resistant cladding powder and commercial 316 alloy powder in an oven at 120 °C for 20 min;

[0068] S3: Use a continuous fiber laser to first clad a layer of 316 coating on the surface of H13 die steel according to the preset laser cladding process parameters. The cladding process parameters are as follows: laser power 2500 W, laser scanning speed 15 mm / s, powder feeding rate 2.0 r / min, spot diameter 4 mm, overlap rate 40%. This process is carried out under argon protection, and the gas flow rate is 15 L / min;

[0069] S4: Use a grinding wheel to grind the 316 cladding layer flat and remove the surface oxide scale.

[0070] S5: Use a continuous fiber laser to clad an iron-based corrosion- and wear-resistant cladding layer on the surface of the 316 transition layer according to the preset laser cladding process parameters.

[0071] The cladding process parameters are as follows: laser power 1500 W, laser scanning speed 8 mm / s, powder feeding rate 0.9 r / min, spot diameter 4 mm, overlap rate 40%. This process is carried out under argon protection, and the gas flow rate is 15 L / min.

[0072] Example 2

[0073] A laser-clad iron-based corrosion- and wear-resistant coating and its preparation method. The composition of the used iron-based corrosion- and wear-resistant cladding powder is as follows:

[0074] 0.2 wt% C, 2.0 wt% B, 12.0 wt% Cr, 0.5 wt% Si, 0.5 wt% Ti, 0.5 wt% Ni, 0.3 wt% Ce, S < 0.03%, P < 0.045%, and the balance is iron.

[0075] The composition of the used commercial 316 alloy powder for the transition layer is as follows:

[0076] 0.05 wt% C, 12.0 wt% Ni, 18.0 wt% Cr, 2.0 wt% Mo, 1.0 wt% Si, 1.0 wt% Mn, P ≤ 0.045%, S ≤ 0.03%, and the balance is Fe.

[0077] The preparation method of the laser-clad iron-based corrosion- and wear-resistant coating is the same as that in Example 1.

[0078] Example 3

[0079] A laser-clad iron-based corrosion- and wear-resistant coating and its preparation method. The composition of the used iron-based corrosion- and wear-resistant cladding powder is as follows:

[0080] 0.4 wt% C, 3.0 wt% B, 16.0 wt% Cr, 1.5 wt% Si, 1.0 wt% Ti, 1.0 wt% Ni, 0.7 wt% Ce, S < 0.03%, P < 0.045%, the balance being iron.

[0081] The composition of the commercially available 316 alloy powder used for the transition layer is as follows:

[0082] 0.05 wt% C, 12.0 wt% Ni, 18.0 wt% Cr, 2.0 wt% Mo, 1.0 wt% Si, 1.0 wt% Mn, P ≤ 0.045%, S ≤ 0.03%, the balance being Fe.

[0083] The preparation method of the laser cladding iron-based corrosion and wear-resistant coating is the same as that in Example 1.

[0084] Example 4

[0085] A laser cladding iron-based corrosion and wear-resistant coating and its preparation method, wherein the compositions of the iron-based corrosion and wear-resistant cladding powder and the commercially available 316 alloy powder are the same as those in Example 1, and the preparation method is the same as that in Example 1.

[0086] The only difference is that the laser power in step S5 is 1300 W.

[0087] Example 5

[0088] A laser cladding iron-based corrosion and wear-resistant coating and its preparation method, wherein the compositions of the iron-based corrosion and wear-resistant cladding powder and the commercially available 316 alloy powder are the same as those in Example 1, and the preparation method is the same as that in Example 1.

[0089] The only difference is that the laser power in step S5 is 1700 W.

[0090] Example 6

[0091] A laser cladding iron-based corrosion and wear-resistant coating and its preparation method, wherein the compositions of the iron-based corrosion and wear-resistant cladding powder and the commercially available 316 alloy powder are the same as those in Example 1.

[0092] The preparation method is the same as that in Example 1, and the only difference is that the laser scanning rate in step S5 is 10 mm / s.

[0093] Characterization of morphology:

[0094] In Examples 1 - 6, a cladding layer with an iron-based corrosion and wear-resistant coating on the surface and a 316 transition layer in the middle was successfully prepared on the H13 substrate. The cladding layer had good forming quality, no cracks and pores, and achieved excellent metallurgical bonding with the substrate. Its cross-sectional morphology is as shown in Figure 1As shown. It can be found in the high-magnification optical microscope image that the iron-based corrosion-resistant and wear-resistant coating is composed of an α-Fe matrix, borides, and ceramic particles, as Figure 2 shown. The α-Fe is in the form of fine equiaxed crystals, the borides are in the form of eutectics wrapping the α-Fe, and the ceramic particles are TiC and TiB2, which are precipitated by the reaction of Ti, C, and B in the melt during solidification and are dispersed in the α-Fe and borides. More specifically, the total thickness of the laser cladding layer is not less than 3 mm. Among them, the average interfacial shear strength between the 316 transition layer and the H13 substrate can reach 503 MPa, and the average interfacial shear strength between the iron-based corrosion-resistant and wear-resistant cladding layer and the 316 transition layer can reach 673 MPa; the size of the α-Fe grains is 1-5 μm; the particle size of the TiC and TiB2 ceramic particles is 100-500 nm, and the volume fraction is 0.8-1.2%.

[0095] Comparative Example 1

[0096] A laser-clad iron-based corrosion-resistant and wear-resistant coating and its preparation method. The composition of the iron-based corrosion-resistant and wear-resistant cladding powder used is the same as that in Example 1. The preparation steps are as follows:

[0097] S1. The surface of the H13 die steel is polished with 240# sandpaper to remove the surface oxide and used as the substrate, and then the surface oil stain is cleaned with anhydrous ethanol and dried.

[0098] S2: The prepared iron-based corrosion-resistant and wear-resistant cladding powder is dried in an oven at 120 °C for 20 min.

[0099] S3: A continuous fiber laser is used to directly clad an iron-based corrosion-resistant and wear-resistant cladding layer on the surface of the H13 die steel according to the preset laser cladding process parameters.

[0100] The cladding process parameters (the same as in Example 1) are as follows:

[0101] Laser power 1500 W, laser scanning speed 8 mm / s, powder feeding rate 0.9 r / min, spot diameter 4 mm, overlap rate 40%. This process is carried out under argon protection, and the gas flow rate is 15 L / min.

[0102] Comparative Example 2

[0103] A laser-clad iron-based corrosion-resistant and wear-resistant coating and its preparation method. The composition of the iron-based corrosion-resistant and wear-resistant cladding powder and the commercial 316 alloy powder used is the same as that in Example 1, and the preparation method is the same as that in Example 1. The only difference is that the laser power in step S5 is 1200 W.

[0104] Comparative Example 3

[0105] A laser cladding iron-based corrosion and wear-resistant coating and its preparation method. The compositions of the iron-based corrosion and wear-resistant cladding powder and the commercial 316 alloy powder used are the same as those in Example 1, and the preparation method is the same as that in Example 1. The only difference is that the laser power in step S5 is 1800W.

[0106] Comparative Example 4

[0107] A laser cladding iron-based corrosion and wear-resistant coating and its preparation method. The compositions of the iron-based corrosion and wear-resistant cladding powder and the commercial 316 alloy powder used are the same as those in Example 1, and the preparation method is the same as that in Example 1. The only difference is that the laser scanning speed in step S5 is 6mm / s.

[0108] Comparative Example 5

[0109] A laser cladding iron-based corrosion and wear-resistant coating and its preparation method. The compositions of the iron-based corrosion and wear-resistant cladding powder and the commercial 316 alloy powder used are the same as those in Example 1, and the preparation method is the same as that in Example 1. The only difference is that the laser scanning speed in step S5 is 12mm / s.

[0110] Comparative Example 6

[0111] A laser cladding iron-based corrosion and wear-resistant coating and its preparation method. The composition of the iron-based corrosion and wear-resistant cladding powder used is as follows:

[0112] 0.3wt% C, 2.5wt% B, 1.0wt% Si, 0.7wt% Ti, 0.7wt% Ni, 0.5wt% Ce, S < 0.03%, P < 0.045%, and the balance is iron.

[0113] The composition of the commercial 316 alloy powder used for the transition layer is as follows:

[0114] 0.05wt% C, 12.0wt% Ni, 18.0wt% Cr, 2.0wt% Mo, 1.0wt% Si, 1.0wt% Mn, P ≤ 0.045%, S ≤ 0.03%, and the balance is Fe.

[0115] The preparation method of the laser cladding iron-based corrosion and wear-resistant coating is the same as that in Example 1.

[0116] Comparative Example 7

[0117] A laser cladding iron-based corrosion and wear-resistant coating and its preparation method. The composition of the iron-based corrosion and wear-resistant cladding powder used is as follows:

[0118] 0.3wt% C, 2.5wt% B, 14.0wt% Cr, 1.0wt% Si, 0.7wt% Ni, 0.5wt% Ce, S < 0.03%, P < 0.045%, and the balance is iron.

[0119] The composition of the commercially available 316 alloy powder used for the transition layer is as follows:

[0120] 0.05 wt% C, 12.0 wt% Ni, 18.0 wt% Cr, 2.0 wt% Mo, 1.0 wt% Si, 1.0 wt% Mn, P ≤ 0.045%, S ≤ 0.03%, and the balance is Fe.

[0121] The preparation method of the laser cladding iron-based corrosion and wear-resistant coating is the same as that in Example 1.

[0122] Comparative Example 8

[0123] A laser cladding iron-based corrosion and wear-resistant coating and its preparation method. The composition of the iron-based corrosion and wear-resistant cladding powder used is as follows:

[0124] 0.3 wt% C, 2.5 wt% B, 14.0 wt% Cr, 1.0 wt% Si, 0.7 wt% Ti, 0.7 wt% Ni, S < 0.03%, P < 0.045%, and the balance is iron.

[0125] The composition of the commercially available 316 alloy powder used for the transition layer is as follows:

[0126] 0.05 wt% C, 12.0 wt% Ni, 18.0 wt% Cr, 2.0 wt% Mo, 1.0 wt% Si, 1.0 wt% Mn, P ≤ 0.045%, S ≤ 0.03%, and the balance is Fe.

[0127] The preparation method of the laser cladding iron-based corrosion and wear-resistant coating is the same as that in Example 1.

[0128] (1) Microstructure observation:

[0129] In Comparative Example 1, the iron-based corrosion and wear-resistant coating was directly cladded on the surface of the H13 substrate, and the interface between the obtained coating and the H13 substrate was poorly bonded, with obvious cracking. In addition, longitudinal through-cracks were also found in the cladding layer.

[0130] In Comparative Example 2, due to too low laser power, part of the powder was not fused, and there were pores in the iron-based corrosion and wear-resistant coating.

[0131] In Comparative Example 3, due to too high laser power, the boride was severely burned out, and the number of the formed corrosion and wear-resistant boride phases was insufficient.

[0132] In Comparative Example 4, due to the relatively slow laser scanning speed, there was a large amount of heat accumulation, and the cladding layer cracked.

[0133] In Comparative Example 5, due to too fast laser scanning speed, the cooling rate of the molten pool was too fast, resulting in cracking of the cladding layer.

[0134] In Comparative Example 6, since there is no Cr element, the boride is brittle Fe2B instead of the toughened (Cr,Fe)2B phase. Cracking occurred in the cladding layer during the laser cladding process.

[0135] In Comparative Example 7, since there is no Ti element, TiC and TiB2 ceramic particles cannot be in-situ generated in the cladding layer. No ceramic particles were observed in the cladding layer.

[0136] In Comparative Example 8, since there is no Ce element, the number of borides decreased, and some eutectic borides showed a continuous network shape. This is because rare earth Ce has high activity, which can reduce the burning loss of borides, purify the molten pool, and modify the borides, reducing the continuity of the network-shaped borides.

[0137] (2) Macroscopic hardness

[0138] The macroscopic hardness of each specimen was tested at room temperature, and the results are shown in Table 1.

[0139]

[0140]

[0141] It can be seen from the test results in Table 1 that:

[0142] The hardness of the surface-clad iron-based corrosion- and wear-resistant coating is more than 20 HRC higher than that of the H13 substrate.

[0143] (3) Wear resistance test

[0144] The reciprocating friction and wear test of each specimen was carried out at room temperature. The friction pair was a Si3N4 ball, the friction load was 60 N, the friction rate was 0.01 m / s, the friction time was 60 min, and the wear volume results are shown in Table 2.

[0145]

[0146]

[0147] It can be seen from the test results in Table 2 that:

[0148] The wear resistance of the surface-clad iron-based corrosion- and wear-resistant coating is 13.5 times that of the H13 substrate. Cracks and pores in the cladding layer and the burning loss and morphology of borides will reduce its wear resistance.

[0149] (4) Aluminum liquid corrosion resistance test

[0150] The corrosion depth of the specimens after being immersed in aluminum liquid at 750 °C for 8 h is shown in Table 3.

[0151]

[0152]

[0153] It can be seen from the test results in Table 3 that:

[0154] The corrosion resistance of the surface-clad iron-based corrosion- and wear-resistant coating to molten aluminum is 16 times that of the H13 substrate.

[0155] The reasons for the poor corrosion resistance of molten aluminum in Comparative Example 1, Comparative Example 4, Comparative Example 5, and Comparative Example 6 are that the clad layer cracks, and the molten aluminum rapidly diffuses inward along the cracks, accelerating the corrosion and spalling of the clad layer.

[0156] The reason for the poor corrosion resistance of molten aluminum in Comparative Example 2 is that the clad layer is not dense enough and there are pores, and the molten aluminum easily penetrates inward along the pores, exacerbating the corrosion.

[0157] The reason for the poor corrosion resistance of molten aluminum in Comparative Example 3 is that the borides in the clad layer are severely burned out, the number of corrosion-resistant phase borides decreases, and the corrosion resistance of molten aluminum is reduced.

[0158] The reason for the poor corrosion resistance of molten aluminum in Comparative Example 7 is that there is a lack of obstruction of ceramic particles to the diffusion of molten aluminum in the iron matrix of the clad layer, reducing the corrosion resistance of molten aluminum.

[0159] The reason for the poor corrosion resistance of molten aluminum in Comparative Example 8 is that the borides in the clad layer are severely burned out and there is a lack of modification with rare earth Ce, and some borides are in a continuous network shape, reducing the corrosion resistance of molten aluminum.

[0160] In the description of this specification, the descriptions with reference to terms such as "one embodiment", "some embodiments", "schematic embodiments", "examples", "specific examples", or "some examples" mean that the specific features, structures, materials, or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0161] Although the embodiments of the present invention have been shown and described, those of ordinary skill in the art can understand that various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principles and purposes of the present invention, and the scope of the present invention is defined by the claims and their equivalents.

Claims

1. A laser cladding iron-based corrosion-resistant and wear-resistant coating, characterized in that: The laser cladding iron-based corrosion-resistant and wear-resistant coating comprises the following corrosion-resistant and wear-resistant iron-based alloy powder components in percentage by mass: C 0.2-0.4％； B 2.0-3.0％； Cr 12.0-16.0％； Ti 0.5-1.0%; Si 0.5-1.5%; Ni 0.5-1.0%; Ce 0.3-0.7%; S＜0.03％； P＜0.045％； The balance is Fe.

2. The laser cladding iron-based corrosion-resistant and wear-resistant coating according to claim 1 is characterized in that: The particle size of the alloy powder is 53 to 150 μm.

3. A method for preparing a laser cladding iron-based corrosion-resistant and wear-resistant coating, characterized in that: The method comprises the following preparation steps: S1: Select H13 mold steel as the substrate, polish the surface of the substrate with sandpaper to remove oxide scale and oil stains, and then clean the polished surface with anhydrous ethanol and dry it; S2: Prepare iron-based alloy powder 1 and iron-based alloy powder 2 before laser cladding, wherein: The iron-based alloy powder 1 is the corrosion-resistant and wear-resistant iron-based alloy powder according to any one of claims 1 or 2; The second iron-based alloy powder is 316 alloy powder; Drying the iron-based alloy powder 1 and the iron-based alloy powder 2 in an oven at 120° C. for 20 minutes; S3: A layer of 316 coating is first clad on the surface of H13 mold steel using a continuous fiber laser according to preset laser cladding process parameters; S4: Use an angle grinder to grind the 316 cladding layer to make it smooth and remove the surface oxide scale; S5: A continuous fiber laser is used to clad an iron-based corrosion-resistant and wear-resistant cladding layer on the surface of the 316 transition layer according to preset laser cladding process parameters.

4. The method for preparing the laser cladding iron-based corrosion-resistant and wear-resistant coating according to claim 3, characterized in that: In step S2, the 316 alloy powder includes the following components in mass percentage: C≤0.08％； Ni 10.0-14.0%, Cr16.0-19.0％； Mo 2.0-3.0%; Si≤1.0%; Mn≤2.0%; P≤0.045％； S≤0.03％； The balance is Fe.

5. The method for preparing the laser cladding iron-based corrosion-resistant and wear-resistant coating according to claim 3, characterized in that: In the step S2, the particle size of the 316 alloy powder is 53-150 μm.

6. The method for preparing the laser cladding iron-based corrosion-resistant and wear-resistant coating according to claim 3, characterized in that: In step S3, the 316 coating clad on the surface of the H13 substrate is a transition layer, and the specific laser cladding process parameters are: laser power 2000-2500W, laser scanning speed 10-15mm / s, powder feeding rate 1.6-2.0r / min, spot diameter 3-4mm, overlap rate 40%.

7. The method for preparing the laser cladding iron-based corrosion-resistant and wear-resistant coating according to claim 3, characterized in that: In the step S3, high-purity argon is used as a shielding gas to protect the molten pool during the laser cladding 316 process, and the argon flow rate is 14-16 L / min; In the step S3, the thickness of the obtained single-layer 316 transition layer is 1.5-2.5 mm.

8. The method for preparing the laser cladding iron-based corrosion-resistant and wear-resistant coating according to claim 3, characterized in that: In step S5, the specific laser cladding process parameters of the iron-based corrosion-resistant and wear-resistant coating are: laser power 1400-1600W, laser scanning speed 8-10mm / s, powder feeding rate 0.8-1.0r / min, spot diameter 3-4mm, and overlap rate 40%.

9. The method for preparing the laser cladding iron-based corrosion-resistant and wear-resistant coating according to claim 3, characterized in that: In the step S5, high-purity argon is used as a protective gas to protect the molten pool during the laser cladding process of the iron-based corrosion-resistant and wear-resistant coating, and the argon flow rate is 14-16 L / min.

10. The method for preparing the laser cladding iron-based corrosion-resistant and wear-resistant coating according to claim 3, characterized in that: In the step S5, the thickness of the obtained iron-based corrosion-resistant and wear-resistant coating is 1.0-2.0 mm.

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