Fe-based composite powder and application of Fe-based composite powder in in-situ generation of TiC / Fe-based composite coating through laser cladding

Abstract

The invention discloses Fe-based composite powder and application of the Fe-based composite powder to in-situ generation of a TiC / Fe-based composite coating through laser cladding, and the Fe-based composite powder is prepared from, by mass, 2%-3% of Ti powder, 4.5%-5.5% of Cr3C2 powder and the balance Fe-based matrix powder; the Fe-based matrix powder is prepared from the following chemical components in percentage by mass: 0.10 to 0.3 percent of C, 13 to 18 percent of Cr, 1.5 to 2.7 percent of Ni, 0.8 to 1.8 percent of Si, 0.8 to 1.4 percent of B, 0.3 to 0.5 percent of Mn, 0.5 to 1.5 percent of Mo and the balance of Fe and inevitable impurities; the Fe-based matrix powder contains Mn and / or Nb, so that the hardness and corrosion potential of the composite coating are effectively improved, and the corrosion current density is reduced.

Description

Technical Field

[0001] The present invention belongs to the technical field of material processing, and in particular relates to an Fe-based composite powder and an application thereof in in-situ generation of a TiC / Fe-based composite coating by laser cladding. Background Art

[0002] Laser cladding is a cutting-edge surface modification technology with unique advantages, including high efficiency and precision, flexibility and innovation, and environmental and economic advantages. It holds broad application prospects across multiple industries. Using a high-energy laser beam, it precisely melts specific materials onto a substrate, enabling the local addition, repair, or reconstruction of materials. Laser cladding is particularly prominent in aerospace, automotive, building materials, energy, furniture, and electrical appliances.

[0003] Traditionally, composite coatings prepared via laser cladding technology typically utilize the direct addition of carbides as a reinforcement phase. While this process is simple and easy to implement, carbides are susceptible to melting, decomposition, or oxidation and burning during the cladding process, leading to cracking in the cladding layer. Furthermore, directly adding carbides as reinforcement phases results in poor wettability with the substrate, reducing bonding and making them susceptible to detachment during wear and corrosion, thereby degrading the overall performance of the composite coating.

[0004] To address the drawbacks of composite coatings produced by directly adding carbides as a reinforcement phase using laser cladding, existing technologies use laser cladding to in-situ generate carbide composite coatings. However, these composite coatings often suffer from defects such as low hardness, low corrosion potential, or high corrosion current density. Summary of the Invention

[0005] In response to the shortcomings of the existing technology, the present invention provides an Fe-based composite powder, which includes: 2% to 3% Ti powder, 4.5% to 5.5% Cr3C2 powder, and the balance Fe-based matrix powder. The Fe-based matrix powder contains Mn and / or Nb, which effectively improves the hardness and corrosion potential of the TiC / Fe-based composite coating and reduces the corrosion current density.

[0006] The object of the present invention is to provide an Fe-based composite powder, which comprises, by mass fraction, 2% to 3% of Ti powder, 4.5% to 5.5% of Cr3C2 powder, and the balance of Fe-based matrix powder;

[0007] Calculated by mass fraction of the Fe-based matrix powder, the chemical composition of the Fe-based matrix powder is: 0.10-0.3% C, 13-18% Cr, 1.5-2.7% Ni, 0.8-1.8% Si, 0.8-1.4% B, 0.3-0.5% Mn, 0.5-1.5% Mo, and the balance Fe and unavoidable impurities.

[0008] In some embodiments of the present invention, the chemical composition of the Fe-based matrix powder is: 0.10-0.3% C, 13-18% Cr, 1.5-2.7% Ni, 0.8-1.8% Si, 0.8-1.4% B, 0.3-0.5% Mn, 0.5-1.5% Mo, 4.5-7.5% Nb, and the balance Fe and unavoidable impurities.

[0009] In some embodiments of the present invention, the particle size of the Fe-based composite powder is in the range of 80-120 μm.

[0010] Another object of the present invention is to provide an application of the Fe-based composite powder in in-situ generation of a TiC / Fe-based composite coating by laser cladding.

[0011] Another object of the present invention is to provide a method for preparing a TiC / Fe-based composite coating by in-situ laser cladding, comprising the following steps:

[0012] S1. By mass fraction, 2% to 3% of Ti powder, 4.5% to 5.5% of Cr3C2 powder and the balance of Fe-based matrix powder are mixed and dried to obtain an Fe-based composite powder; by mass fraction of the Fe-based matrix powder, the chemical composition of the Fe-based matrix powder is: 0.10-0.3% C, 13-18% Cr, 1.5-2.7% Ni, 0.8-1.8% Si, 0.8-1.4% B, 0.3-0.5% Mn, 0.5-1.5% Mo, the balance Fe and unavoidable impurities;

[0013] S2. Pre-treating the tool surface to remove oil and impurities attached to the tool surface;

[0014] S3. Use laser cladding technology to clad the Fe-based composite powder on the surface of the tool, so that the Fe-based composite powder forms a TiC / Fe-based composite coating on the surface of the tool.

[0015] In some embodiments of the present invention, in S1, the chemical composition of the Fe-based matrix powder is: 0.10-0.3% C, 13-18% Cr, 1.5-2.7% Ni, 0.8-1.8% Si, 0.8-1.4% B, 0.3-0.5% Mn, 0.5-1.5% Mo, 4.5-7.5% Nb, and the remainder Fe and unavoidable impurities.

[0016] In some embodiments of the present invention, in S2, the material of the cutting tool is one of carbon steel, alloy steel, and stainless steel.

[0017] In some embodiments of the present invention, step S3 includes: heating the Fe-based composite powder and cladding the Fe-based composite powder on the tool surface using laser cladding technology, so that the Fe-based composite powder forms a TiC / Fe-based composite coating on the tool surface.

[0018] In some embodiments of the present invention, in S3, the technical parameters of the laser cladding technology are as follows: the laser cladding power is 1000~3000W;

[0019] Among them, the cladding method is a coaxial powder feeding method, the laser scanning speed of the coaxial powder feeding is 800~1200Hz, the spot diameter is 4~6mm, the cladding speed is 150~250mm / min, and the powder feeding amount is 20~24g / min.

[0020] In some embodiments of the present invention, in S3, the thickness of the TiC / Fe-based composite coating formed on the surface of the tool is 0.5 mm to 2.0 mm.

[0021] In some embodiments of the present invention, in S3, after the Fe-based composite powder is clad on the surface of the tool using the laser cladding technology, a post-processing step is also included.

[0022] In some embodiments of the present invention, the post-processing step includes cooling to 40-100° C., pickling, and polishing.

[0023] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0024] The present invention adds Cr3C2 and Ti powders to Fe-based matrix powder, clads the composite powder onto kitchen knives, and generates a TiC / Fe-based composite coating in situ by laser cladding, thereby improving the hardness and corrosion resistance of the knives. DETAILED DESCRIPTION

[0025] In order to enable those skilled in the art to better understand the technical solutions of the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts should fall within the scope of protection of the present invention.

[0026] Example 1: In-situ generation of TiC / Fe-based composite coating by laser cladding.

[0027] S1. 2% Ti powder, 5.5% Cr3C2 powder, and the remainder Fe-based matrix powder were mixed and dried to obtain an Fe-based composite powder; the chemical composition of the Fe-based matrix powder was as follows: 0.10% C, 18% Cr, 1.5% Ni, 1.8% Si, 0.8% B, 0.5% Mn, 0.5% Mo, and the remainder Fe and unavoidable impurities, based on the mass fraction of the Fe-based matrix powder; the particle size of the Fe-based composite powder ranged from 80 to 120 μm;

[0028] S2. Pre-treat the surface of the carbon steel tool by polishing it with metallographic sandpaper to remove oil and impurities adhering to the surface of the carbon steel tool;

[0029] S3. Laser cladding technology is used to clad Fe-based composite powder on the surface of a carbon steel tool. The laser cladding power is 1000W, and the cladding method is a coaxial powder feeding method. The laser scanning speed of the coaxial powder feeding is 1200Hz, the spot diameter is 4mm, the cladding speed is 250mm / min, and the powder feeding amount is 20g / min. The Fe-based composite powder forms a TiC / Fe-based composite coating on the surface of the carbon steel tool. After the TiC / Fe-based composite coating is formed, the temperature is lowered to 40°C, pickled, and polished to form a TiC / Fe-based composite coating with a thickness of 0.5mm on the surface of the carbon steel tool.

[0030] Example 2: In-situ generation of TiC / Fe-based composite coating using laser cladding.

[0031] S1. By mass fraction, 3% Ti powder, 4.5% Cr3C2 powder, and the balance Fe-based matrix powder were mixed and dried to obtain an Fe-based composite powder; the chemical composition of the Fe-based matrix powder was as follows: 0.3% C, 13% Cr, 2.7% Ni, 0.8% Si, 1.4% B, 0.3% Mn, 1.5% Mo, and the balance Fe and unavoidable impurities; the particle size of the Fe-based composite powder ranged from 80 to 120 μm;

[0032] S2. Pre-treat the surface of the stainless steel tool by polishing it with metallographic sandpaper to remove oil and impurities attached to the surface of the stainless steel tool;

[0033] S3. Laser cladding technology is used to clad Fe-based composite powder on the surface of the stainless steel tool. The laser cladding power is 3000W, and the cladding method is coaxial powder feeding. The laser scanning speed of the coaxial powder feeding is 800Hz, the spot diameter is 6mm, the cladding speed is 150mm / min, and the powder feeding amount is 24g / min. The Fe-based composite powder forms a TiC / Fe-based composite coating on the surface of the stainless steel tool. After the TiC / Fe-based composite coating is formed, the temperature is lowered to 100℃, pickled, and polished to form a TiC / Fe-based composite coating with a thickness of 2.0mm on the surface of the stainless steel tool.

[0034] Example 3: In-situ generation of TiC / Fe-based composite coating using laser cladding.

[0035] S1. 2.5% Ti powder, 5% Cr3C2 powder, and the remainder Fe-based matrix powder were mixed and dried to obtain an Fe-based composite powder; the chemical composition of the Fe-based matrix powder was as follows: 0.2% C, 15% Cr, 2.2% Ni, 1.2% Si, 1.1% B, 0.4% Mn, 1% Mo, and the remainder Fe and unavoidable impurities, based on the mass fraction of the Fe-based matrix powder; the particle size of the Fe-based composite powder ranged from 80 to 120 μm;

[0036] S2. Pre-treat the surface of the alloy steel tool by polishing the surface of the alloy steel tool with metallographic sandpaper to remove oil and impurities adhering to the surface of the alloy steel tool;

[0037] S3. Laser cladding technology is used to clad Fe-based composite powder on the surface of the alloy steel tool. The laser cladding power is 2000W, and the cladding method is coaxial powder feeding. The laser scanning speed of the coaxial powder feeding is 1000Hz, the spot diameter is 5mm, the cladding speed is 200mm / min, and the powder feeding amount is 22g / min. The Fe-based composite powder forms a TiC / Fe-based composite coating on the surface of the alloy steel tool. After the TiC / Fe-based composite coating is formed, the temperature is lowered to 70℃, pickled, and polished to form a TiC / Fe-based composite coating with a thickness of 1.3mm on the surface of the alloy steel tool.

[0038] Example 4: In-situ generation of TiC / Fe-based composite coating using laser cladding.

[0039] S1. 2.5% Ti powder, 5% Cr3C2 powder, and the remainder Fe-based matrix powder were mixed and dried to obtain an Fe-based composite powder; the chemical composition of the Fe-based matrix powder was as follows: 0.2% C, 15% Cr, 2.2% Ni, 1.2% Si, 1.1% B, 0.4% Mn, 1% Mo, and the remainder Fe and unavoidable impurities, based on the mass fraction of the Fe-based matrix powder; the particle size of the Fe-based composite powder ranged from 80 to 120 μm;

[0040] S2. Pre-treat the surface of the alloy steel tool by polishing the surface of the alloy steel tool with metallographic sandpaper to remove oil and impurities adhering to the surface of the alloy steel tool;

[0041] S3. Heat the Fe-based composite powder and use laser cladding technology to clad the Fe-based composite powder on the surface of the alloy steel tool. The laser cladding power is 2000W, and the cladding method is a coaxial powder feeding method. The laser scanning speed of the coaxial powder feeding is 1000Hz, the spot diameter is 5mm, the cladding speed is 200mm / min, and the powder feeding amount is 22g / min, so that the Fe-based composite powder forms a TiC / Fe-based composite coating on the surface of the alloy steel tool. After the TiC / Fe-based composite coating is formed, the temperature is lowered to 70℃, pickled, and polished to form a TiC / Fe-based composite coating with a thickness of 1.3mm on the surface of the alloy steel tool.

[0042] Example 5: In-situ generation of TiC / Fe-based composite coating using laser cladding.

[0043] S1. 2% Ti powder, 5.5% Cr3C2 powder, and the remainder Fe-based matrix powder were mixed and dried to obtain an Fe-based composite powder; the chemical composition of the Fe-based matrix powder was as follows: 0.10% C, 18% Cr, 1.5% Ni, 1.8% Si, 0.8% B, 0.5% Mn, 0.5% Mo, 4.5% Nb, and the remainder Fe and unavoidable impurities, based on the mass fraction of the Fe-based matrix powder; the particle size of the Fe-based composite powder ranged from 80 to 120 μm;

[0044] S2. Pre-treat the surface of the carbon steel tool by polishing it with metallographic sandpaper to remove oil and impurities adhering to the surface of the carbon steel tool;

[0045] S3. Laser cladding technology is used to clad Fe-based composite powder on the surface of a carbon steel tool. The laser cladding power is 1000W, and the cladding method is a coaxial powder feeding method. The laser scanning speed of the coaxial powder feeding is 1200Hz, the spot diameter is 4mm, the cladding speed is 250mm / min, and the powder feeding amount is 20g / min. The Fe-based composite powder forms a TiC / Fe-based composite coating on the surface of the carbon steel tool. After the TiC / Fe-based composite coating is formed, the temperature is lowered to 40°C, pickled, and polished to form a TiC / Fe-based composite coating with a thickness of 0.5mm on the surface of the carbon steel tool.

[0046] Example 6: In-situ generation of TiC / Fe-based composite coating using laser cladding.

[0047] S1. 3% Ti powder, 4.5% Cr3C2 powder, and the remainder Fe-based matrix powder were mixed and dried to obtain an Fe-based composite powder; the chemical composition of the Fe-based matrix powder was as follows: 0.3% C, 13% Cr, 2.7% Ni, 0.8% Si, 1.4% B, 0.3% Mn, 1.5% Mo, 7.5% Nb, and the remainder Fe and unavoidable impurities, based on the mass fraction of the Fe-based matrix powder; the particle size of the Fe-based composite powder ranged from 80 to 120 μm;

[0048] S2. Pre-treat the surface of the stainless steel tool by polishing it with metallographic sandpaper to remove oil and impurities attached to the surface of the stainless steel tool;

[0049] S3. Laser cladding technology is used to clad Fe-based composite powder on the surface of the stainless steel tool. The laser cladding power is 3000W, and the cladding method is coaxial powder feeding. The laser scanning speed of the coaxial powder feeding is 800Hz, the spot diameter is 6mm, the cladding speed is 150mm / min, and the powder feeding amount is 24g / min. The Fe-based composite powder forms a TiC / Fe-based composite coating on the surface of the stainless steel tool. After the TiC / Fe-based composite coating is formed, the temperature is lowered to 100℃, pickled, and polished to form a TiC / Fe-based composite coating with a thickness of 2.0mm on the surface of the stainless steel tool.

[0050] Example 7: In-situ generation of TiC / Fe-based composite coating using laser cladding.

[0051] S1. 2.5% Ti powder, 5% Cr3C2 powder, and the remainder Fe-based matrix powder were mixed and dried to obtain an Fe-based composite powder; the chemical composition of the Fe-based matrix powder was as follows: 0.2% C, 15% Cr, 2.2% Ni, 1.2% Si, 1.1% B, 0.4% Mn, 1% Mo, 6% Nb, and the remainder Fe and unavoidable impurities, based on the mass fraction of the Fe-based matrix powder; the particle size of the Fe-based composite powder ranged from 80 to 120 μm;

[0052] S2. Pre-treat the surface of the alloy steel tool by polishing the surface of the alloy steel tool with metallographic sandpaper to remove oil and impurities adhering to the surface of the alloy steel tool;

[0053] S3. Laser cladding technology is used to clad Fe-based composite powder on the surface of the alloy steel tool. The laser cladding power is 2000W, and the cladding method is coaxial powder feeding. The laser scanning speed of the coaxial powder feeding is 1000Hz, the spot diameter is 5mm, the cladding speed is 200mm / min, and the powder feeding amount is 22g / min. The Fe-based composite powder forms a TiC / Fe-based composite coating on the surface of the alloy steel tool. After the TiC / Fe-based composite coating is formed, the temperature is lowered to 70℃, pickled, and polished to form a TiC / Fe-based composite coating with a thickness of 1.3mm on the surface of the alloy steel tool.

[0054] Example 8: In-situ generation of TiC / Fe-based composite coating using laser cladding.

[0055] S1. 2.5% Ti powder, 5% Cr3C2 powder, and the remainder Fe-based matrix powder were mixed and dried to obtain an Fe-based composite powder; the chemical composition of the Fe-based matrix powder was as follows: 0.2% C, 15% Cr, 2.2% Ni, 1.2% Si, 1.1% B, 0.4% Mn, 1% Mo, 6% Nb, and the remainder Fe and unavoidable impurities, based on the mass fraction of the Fe-based matrix powder; the particle size of the Fe-based composite powder ranged from 80 to 120 μm;

[0056] S2. Pre-treat the surface of the alloy steel tool by polishing the surface of the alloy steel tool with metallographic sandpaper to remove oil and impurities adhering to the surface of the alloy steel tool;

[0057] S3. Heat the Fe-based composite powder and use laser cladding technology to clad the Fe-based composite powder on the surface of the alloy steel tool. The laser cladding power is 2000W, and the cladding method is a coaxial powder feeding method. The laser scanning speed of the coaxial powder feeding is 1000Hz, the spot diameter is 5mm, the cladding speed is 200mm / min, and the powder feeding amount is 22g / min, so that the Fe-based composite powder forms a TiC / Fe-based composite coating on the surface of the alloy steel tool. After the TiC / Fe-based composite coating is formed, the temperature is lowered to 70℃, pickled, and polished to form a TiC / Fe-based composite coating with a thickness of 1.3mm on the surface of the alloy steel tool.

[0058] Comparative Example 1: In-situ generation of a TiC / Fe-based composite coating using laser cladding.

[0059] Compared with Example 3, the Fe-based matrix powder does not contain Mn, and the other steps are consistent with Example 3.

[0060] S1. By mass fraction, 2.5% Ti powder, 5% Cr3C2 powder, and the balance Fe-based matrix powder were mixed and dried to obtain an Fe-based composite powder; the chemical composition of the Fe-based matrix powder was as follows: 0.2% C, 15% Cr, 2.2% Ni, 1.2% Si, 1.1% B, 1% Mo, and the balance Fe and unavoidable impurities; the particle size of the Fe-based composite powder ranged from 80 to 120 μm;

[0061] S2. Pre-treat the surface of the alloy steel tool by polishing the surface of the alloy steel tool with metallographic sandpaper to remove oil and impurities adhering to the surface of the alloy steel tool;

[0062] S3. Laser cladding technology is used to clad Fe-based composite powder on the surface of the alloy steel tool. The laser cladding power is 2000W, and the cladding method is coaxial powder feeding. The laser scanning speed of the coaxial powder feeding is 1000Hz, the spot diameter is 5mm, the cladding speed is 200mm / min, and the powder feeding amount is 22g / min. The Fe-based composite powder forms a TiC / Fe-based composite coating on the surface of the alloy steel tool. After the TiC / Fe-based composite coating is formed, the temperature is lowered to 70℃, pickled, and polished to form a TiC / Fe-based composite coating with a thickness of 1.3mm on the surface of the alloy steel tool.

[0063] Comparative Example 2: In-situ generation of a TiC / Fe-based composite coating using laser cladding.

[0064] Compared with Example 4, the Fe-based matrix powder does not contain Mn, and the other steps are consistent with Example 4.

[0065] S1. 2.5% Ti powder, 5% Cr3C2 powder, and the remainder Fe-based matrix powder were mixed and dried to obtain an Fe-based composite powder; the chemical composition of the Fe-based matrix powder was as follows: 0.2% C, 15% Cr, 2.2% Ni, 1.2% Si, 1.1% B, 0.4% Mn, 1% Mo, and the remainder Fe and unavoidable impurities, based on the mass fraction of the Fe-based matrix powder; the particle size of the Fe-based composite powder ranged from 80 to 120 μm;

[0066] S2. Pre-treat the surface of the alloy steel tool by polishing the surface of the alloy steel tool with metallographic sandpaper to remove oil and impurities adhering to the surface of the alloy steel tool;

[0067] S3. Heat the Fe-based composite powder and use laser cladding technology to clad the Fe-based composite powder on the surface of the alloy steel tool. The laser cladding power is 2000W, and the cladding method is a coaxial powder feeding method. The laser scanning speed of the coaxial powder feeding is 1000Hz, the spot diameter is 5mm, the cladding speed is 200mm / min, and the powder feeding amount is 22g / min, so that the Fe-based composite powder forms a TiC / Fe-based composite coating on the surface of the alloy steel tool. After the TiC / Fe-based composite coating is formed, the temperature is lowered to 70℃, pickled, and polished to form a TiC / Fe-based composite coating with a thickness of 1.3mm on the surface of the alloy steel tool.

[0068] The corrosion resistance of the TiC / Fe-based composite coatings prepared in Examples 1-8 and Comparative Examples 1-2 was tested in a 3.5wt% NaCl neutral corrosion solution. The corrosion potential and corrosion current density were measured using a three-electrode electrochemical system with a sample working electrode, a platinum counter electrode, and a saturated calomel reference electrode. The results are shown in Table 1.

[0069] Table 1. Properties of TiC / Fe-based composite coatings.

[0070] sample <![CDATA[Hardness / HV 0,2 > Self-corrosion potential / V <![CDATA[Self-corrosion current density / 10 -6 A / cm2]]> Example 1 720 -0.85 0.24 Example 2 703 -0.87 0.27 Example 3 738 -0.82 0.22 Example 4 654 -0.89 0.28 Example 5 816 -0.74 0.20 Example 6 809 -0.76 0.21 Example 7 835 -0.70 0.17 Example 8 822 -0.73 0.19 Comparative Example 1 467 -1.22 0.82 Comparative Example 2 374 -1.24 0.85

[0071] As can be seen from Table 1, the Fe-based matrix powder of the present invention contains Mn and / or Nb, which effectively improves the hardness and corrosion potential of the composite coating and reduces the corrosion current density.

[0072] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit it. Although the present invention has been described in detail with reference to the above embodiments, ordinary technicians in the relevant field should understand that after reading the specification of this application, technicians can still modify or replace the specific implementation methods of the present invention with equivalents, but these modifications or changes do not depart from the scope of protection of the pending claims of the present application.

Claims

1. An Fe-based composite powder, characterized in that: Calculated by mass fraction, it includes: Ti powder 2%~3%, Cr3C2 powder 4.5%~5.5%, and the balance Fe-based matrix powder; Calculated by mass fraction of the Fe-based matrix powder, the chemical composition of the Fe-based matrix powder is: 0.10-0.3% C, 13-18% Cr, 1.5-2.7% Ni, 0.8-1.8% Si, 0.8-1.4% B, 0.3-0.5% Mn, 0.5-1.5% Mo, and the balance Fe and unavoidable impurities.

2. The Fe-based composite powder according to claim 1, characterized in that The chemical composition of the Fe-based matrix powder is: 0.10-0.3% C, 13-18% Cr, 1.5-2.7% Ni, 0.8-1.8% Si, 0.8-1.4% B, 0.3-0.5% Mn, 0.5-1.5% Mo, 4.5-7.5% Nb, and the balance Fe and unavoidable impurities.

3. The Fe-based composite powder according to claim 1, characterized in that The particle size of the Fe-based composite powder is in the range of 80 to 120 μm.

4. Use of the Fe-based composite powder according to any one of claims 1 to 3 in in-situ generation of a TiC / Fe-based composite coating by laser cladding.

5. A method for preparing a TiC / Fe-based composite coating by in-situ laser cladding, characterized in that: The steps include: S1. By mass fraction, 2% to 3% of Ti powder, 4.5% to 5.5% of Cr3C2 powder and the balance of Fe-based matrix powder are mixed and dried to obtain an Fe-based composite powder; by mass fraction of the Fe-based matrix powder, the chemical composition of the Fe-based matrix powder is: 0.10-0.3% C, 13-18% Cr, 1.5-2.7% Ni, 0.8-1.8% Si, 0.8-1.4% B, 0.3-0.5% Mn, 0.5-1.5% Mo, the balance Fe and unavoidable impurities; S2. Pre-treating the tool surface to remove oil and impurities attached to the tool surface; S3. Use laser cladding technology to clad the Fe-based composite powder on the surface of the tool, so that the Fe-based composite powder forms a TiC / Fe-based composite coating on the surface of the tool.

6. The method for preparing a TiC / Fe-based composite coating by in-situ laser cladding according to claim 5, characterized in that: In S1, the chemical composition of the Fe-based matrix powder is: 0.10-0.3% C, 13-18% Cr, 1.5-2.7% Ni, 0.8-1.8% Si, 0.8-1.4% B, 0.3-0.5% Mn, 0.5-1.5% Mo, 4.5-7.5% Nb, and the balance Fe and unavoidable impurities.

7. The method for preparing a TiC / Fe-based composite coating by in-situ laser cladding according to claim 5, wherein: In S2, the material of the cutting tool is one of carbon steel, alloy steel and stainless steel.

8. The method for preparing a TiC / Fe-based composite coating by in-situ laser cladding according to claim 5, wherein: The step of S3 includes: heating the Fe-based composite powder, and cladding the Fe-based composite powder on the surface of the tool using a laser cladding technology, so that the Fe-based composite powder forms a TiC / Fe-based composite coating on the surface of the tool.

9. The method for preparing a TiC / Fe-based composite coating by in-situ laser cladding according to claim 5, wherein: In S3, the technical parameters of the laser cladding technology are as follows: the laser cladding power is 1000~3000W; Among them, the cladding method is a coaxial powder feeding method, the laser scanning speed of the coaxial powder feeding is 800~1200Hz, the spot diameter is 4~6mm, the cladding speed is 150~250mm / min, and the powder feeding amount is 20~24g / min.

10. The method for preparing the Fe-based composite powder according to claim 5, wherein: In S3, the thickness of the TiC / Fe-based composite coating formed on the surface of the tool is 0.5 mm to 2.0 mm.