High-entropy alloy flux-cored wire for stainless steel wear-resistant coating and method of making same

Abstract

The application discloses a high-entropy alloy core wire for stainless steel wear-resistant coating, which is composed of a sheath and a core, and the core is composed of the following components in percentage by mass: Co: 16.5-20%, Cr: 14.8-17.6%, Ni: 16.5-20%, Nb: 42.4-52.2%; the sum of the above components is 100%; the sheath is an Fe-Co-Ni alloy strip; the sheath is composed of the following components in percentage by mass: silicon: ≤0.1%, manganese: ≤0.26%, nickel: 29.08-30%, cobalt: 17.31-18%, copper: ≤0.011%, chromium: ≤0.006%, and the balance is Fe. In the preparation method of the core wire, the core is wrapped in the sheath, and the core wire is prepared through drawing and reducing; the core wire is suitable for the preparation of wear-resistant coatings on various stainless steels, has good wear resistance and corrosion resistance, and has a lower cost than Co core wire.

Description

Technical Field

[0001] This invention belongs to the field of metal materials technology, and relates to a high-entropy alloy flux-cored wire for wear-resistant coating of stainless steel; it also relates to a method for preparing the high-entropy alloy flux-cored wire for wear-resistant coating of stainless steel. Background Technology

[0002] Due to its excellent corrosion resistance and strength, stainless steel is widely used in automobiles, building materials, chemical equipment, transportation equipment, and other fields. However, prolonged use often leads to wear and tear, causing parts and equipment to fail. Therefore, there is a significant demand for surface improvement technologies, and coating preparation is one of the most efficient methods to improve the surface properties of the substrate. Currently, traditional cladding layers use a single main element as the matrix and are formulated by adding other trace elements, such as Fe-based and Co-based. Among them, wear-resistant cladding layers prepared with Fe-based welding wire are enhanced by adding other reinforcing particles or reinforcing phases to improve the strength of the cladding layer. This type of cladding layer is relatively inexpensive and has good wear resistance, but its poor corrosion resistance makes it unsuitable for stainless steel surface protection. Co-based cladding layers are known for their high wear resistance and corrosion resistance. The main reason for the excellent corrosion resistance and wear resistance of Co-based cladding layers is the strain-induced transformation of FCC to HCP martensite. Although its performance is excellent, the preparation cost of Co-based cladding layers is extremely high. High-entropy alloys are a type of multi-principal element alloy that has been developed in recent years. They are generally composed of five or more main elements, with the molar content of each main element ranging from 5% to 35%. Due to their four major effects, they possess excellent wear resistance and corrosion resistance. However, current methods for preparing high-entropy alloy coatings are mainly focused on laser cladding. Although this method has advantages such as high heat concentration and minimal impact on the substrate, it suffers from disadvantages such as low efficiency, high preparation cost, and high processing requirements in mass production. TIG cladding, on the other hand, is a low-cost, high-efficiency method for preparing coatings, with lower requirements for the production environment, making it suitable for mass production. Summary of the Invention

[0003] The purpose of this invention is to provide a high-entropy alloy flux-cored welding wire for wear-resistant coatings of stainless steel, which solves the problems of high cost of existing Co-based welding wires and poor corrosion resistance of Fe-based welding wires.

[0004] Another objective of this invention is to provide a method for preparing high-entropy alloy flux-cored welding wire for wear-resistant coatings on stainless steel.

[0005] The first technical solution adopted in this invention is a high-entropy alloy flux-cored welding wire for wear-resistant coating of stainless steel, which consists of a welding skin and a flux core. The flux core is composed of the following components by mass percentage: Co: 16.5%–20%, Cr: 14.8%–17.6%, Ni: 16.5%–20%, Nb: 42.4%–52.2%, and the sum of the above component percentages is 100%; the flux core filling rate is 38wt%–42wt%.

[0006] The invention is further characterized in that,

[0007] The weld bead is an Fe-Co-Ni alloy strip; the composition of the weld bead by mass percentage is: Si: ≤0.1%, Mn: ≤0.26%, Ni: 29.08%~30%, Co: 17.31%~18%, Cu: ≤0.011%, Cr: ≤0.006%, with the balance being Fe.

[0008] The specific basis for designing the chemical composition of the welding wire in this invention is as follows:

[0009] Co, Ni, and Cr: These elements have similar atomic radii and electronegativity to Fe, readily forming a single solid solution with Fe, thus inhibiting the formation of intermetallic compounds. Furthermore, Co and Ni are corrosion-resistant elements, improving the corrosion resistance of coatings. Cr can regulate elemental distribution and refine grain size.

[0010] Nb: Compared to the other three elements, Nb is a large atomic radius element, which can disrupt the crystal lattice structure and cause lattice distortion, thereby preventing dislocations and enhancing the hardness and wear resistance of the coating. In addition, Nb has good corrosion resistance in harsh environments such as high temperature, high pressure, strong acid and strong alkali, which can meet a variety of application requirements.

[0011] The second technical solution adopted in this invention is: a method for preparing high-entropy alloy flux-cored welding wire for stainless steel wear-resistant coating, the specific operation steps of which are as follows:

[0012] Step 1: First, clean the Fe-Co-Ni alloy strip with a mixture of NaOH and acetone. After cleaning, rinse with water and then use a mixed aqueous solution of HF and HNO3 for ultrasonic cleaning to obtain the cleaned Fe-Co-Ni alloy strip.

[0013] Step 2: Weigh the following materials for the core according to the following mass percentages: 16.5%–20%, Cr: 14.8%–17.6%, Ni: 16.5%–20%, Nb: 42.4%–52.2%, and the sum of the mass percentages of the above materials is 100%.

[0014] Step 3: Dry mix the various raw material powders heated in Step 2 in a mixer until they are evenly mixed to obtain core powder;

[0015] Step 4: The flux-cored powder uniformly mixed in Step 3 is wrapped in Fe-Co-Ni alloy strip using a flux-cored wire forming machine, and the Fe-Co-Ni alloy strip is closed using a forming machine to obtain a semi-finished welding wire.

[0016] Step 5: The semi-finished welding wire obtained in Step 4 is subjected to multiple cold drawing and diameter reduction dies to obtain the welding wire;

[0017] Step 6: Wipe the oil stains on the welding wire with a cotton cloth soaked in acetone or anhydrous ethanol. Finally, straighten the welding wire, coil it into a disc, and seal it in packaging using a wire drawing machine.

[0018] The invention is further characterized in that,

[0019] In step 1, the NaOH and acetone mixture used has a NaOH mass fraction of 15% and an acetone mass fraction of 85%. The HF and HNO3 mixed aqueous solution has a HF mass fraction of 5% and an HNO3 mass fraction of 35%. Ultrasonic cleaning is performed for 1–2 minutes at a frequency of 20–30 kHz.

[0020] In step 2, the particle size of each raw material powder is no greater than 124 μm.

[0021] In step 5, the specific process of the multi-pass cold drawing and diameter reduction wire drawing die is as follows: the wire passes through wire drawing dies with diameters of 2.0mm, 1.9mm, 1.8mm, 1.7mm, 1.6mm, 1.5mm, and 1.42mm in sequence.

[0022] The beneficial effects of this invention are:

[0023] (1) The high-entropy alloy flux-cored wire of the present invention is used for the preparation of wear-resistant coatings on stainless steel, and proposes a solution to the wear failure problem of stainless steel workpieces.

[0024] (2) The high-entropy alloy flux-cored welding wire of the present invention has good weldability, stable arc, good wetting and spreading performance, beautiful weld formation, and no defects such as cracks, pores, inclusions, or oxidation.

[0025] (3) The preparation method of the flux-cored welding wire of the present invention is simple, highly operable, low in cost and suitable for mass production. Attached Figure Description

[0026] Figure 1 This is a microstructure diagram of the high-entropy alloy flux-cored welding wire used in the present invention for stainless steel wear-resistant coating. Detailed Implementation

[0027] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0028] This invention relates to a high-entropy alloy flux-cored welding wire for wear-resistant coatings on stainless steel, comprising a welding sheath and a flux core. The flux core is composed of the following components by mass percentage: Co: 16.5%–20%, Cr: 14.8%–17.6%, Ni: 16.5%–20%, Nb: 42.4%–52.2%, with the sum of the above component percentages being 100%. The filling rate of the flux core is 38wt%–42wt%.

[0029] The weld bead is an Fe-Co-Ni alloy strip; the composition of the weld bead by mass percentage is: Si: ≤0.1%, Mn: ≤0.26%, Ni: 29.08%~30%, Co: 17.31%~18%, Cu: ≤0.011%, Cr: ≤0.006%, with the balance being Fe.

[0030] Example 1

[0031] Step 1: First, clean the Fe-Co-Ni alloy strip with a mixture of NaOH and acetone. After cleaning, rinse with water and then use a mixed aqueous solution of HF and HNO3 for ultrasonic cleaning to obtain the cleaned Fe-Co-Ni alloy strip.

[0032] In step 1, the NaOH and acetone mixture used had a NaOH mass fraction of 15% and an acetone mass fraction of 85%. The HF and HNO3 mixed aqueous solution had a HF mass fraction of 5% and an HNO3 mass fraction of 35%. Ultrasonic cleaning was performed for 1 min at a frequency of 30 kHz.

[0033] Step 2: Prepare the mixture according to the mass percentages, with a total mass percentage of 100%, including Co: 20%, Cr: 17.6%, Ni: 20%, and Nb: 42.4%. Weigh out the various metal powders according to the mass percentages.

[0034] In step 2, the particle size of each raw material powder is no greater than 124 μm.

[0035] Step 3: Dry mix the various raw material powders heated in Step 2 in a mixer until they are evenly mixed to obtain core powder;

[0036] Step 4: The flux powder uniformly mixed in Step 3 is wrapped in Fe-Co-Ni alloy strip using a flux-cored wire forming machine, and the Fe-Co-Ni alloy strip is closed using a forming machine to obtain a 2.1mm diameter welding wire semi-finished product.

[0037] Step 5: The high-entropy alloy flux-cored welding wire precursor with a diameter of 2.1 mm obtained in Step 4 is subjected to a multi-pass cold drawing and diameter reduction die to obtain a welding wire with a diameter of 1.42 mm;

[0038] In step 5, the specific process of the multi-pass cold drawing and diameter reduction wire drawing die is as follows: the wire passes through wire drawing dies with diameters of 2.0mm, 1.9mm, 1.8mm, 1.7mm, 1.6mm, 1.5mm, and 1.42mm in sequence.

[0039] Step 6: Wipe the oil stains on the welding wire with a cotton cloth soaked in acetone or anhydrous ethanol. Finally, straighten the welding wire, coil it into a disc, and seal it in packaging using a wire drawing machine.

[0040] The welding process of the high-entropy alloy flux-cored welding wire prepared in Example 1 was as follows: Tungsten inert gas (TIG) welding was used, with a welding current of 170 A, a voltage of 15–20 V, a welding speed of 15 cm / min, and pure argon as the shielding gas. This welding wire produced a stable arc, aesthetically pleasing weld formation, and was free of defects such as porosity, cracks, inclusions, and oxidation. The resulting high-entropy alloy wear-resistant coating achieved a maximum hardness of 530 HV. 0.5 Its hardness is 2.4 times higher than that of the base material, and it has excellent wear resistance, meeting the requirements for use.

[0041] Example 2

[0042] Step 1: First, clean the Fe-Co-Ni alloy strip with a mixture of NaOH and acetone. After cleaning, rinse with water and then use a mixed aqueous solution of HF and HNO3 for ultrasonic cleaning to obtain the cleaned Fe-Co-Ni alloy strip.

[0043] In step 1, the NaOH and acetone mixture used had a NaOH mass fraction of 15% and an acetone mass fraction of 85%. The HF and HNO3 mixed aqueous solution had a HF mass fraction of 5% and an HNO3 mass fraction of 35%. Ultrasonic cleaning was performed for 2 minutes at a frequency of 20 kHz.

[0044] Step 2: Prepare the mixture according to the mass percentages, with a total mass percentage of 100%, including Co: 18.8%, Cr: 16.6%, Ni: 18.8%, and Nb: 45.8%. Weigh out the various metal powders according to the mass percentages.

[0045] In step 2, the particle size of each raw material powder is no greater than 124 μm.

[0046] Step 3: Dry mix the various raw material powders heated in Step 2 in a mixer until they are evenly mixed to obtain core powder;

[0047] Step 4: The flux powder uniformly mixed in Step 3 is wrapped in Fe-Co-Ni alloy strip using a flux-cored wire forming machine, and the Fe-Co-Ni alloy strip is closed using a forming machine to obtain a 2.1mm diameter welding wire semi-finished product.

[0048] Step 5: The high-entropy alloy flux-cored welding wire precursor with a diameter of 2.1 mm obtained in Step 4 is subjected to a multi-pass cold drawing and diameter reduction die to obtain a welding wire with a diameter of 1.42 mm;

[0049] In step 5, the specific process of the multi-pass cold drawing and diameter reduction wire drawing die is as follows: the wire passes through wire drawing dies with diameters of 2.0mm, 1.9mm, 1.8mm, 1.7mm, 1.6mm, 1.5mm, and 1.42mm in sequence.

[0050] Step 6: Wipe the oil stains on the welding wire with a cotton cloth soaked in acetone or anhydrous ethanol. Finally, straighten the welding wire, coil it into a disc, and seal it in packaging using a wire drawing machine.

[0051] The welding process of the high-entropy alloy flux-cored welding wire prepared in Example 2 is as follows: Tungsten inert gas (TIG) welding is used, with a welding current of 170A, a voltage of 15-20V, a welding speed of 15cm / min, and pure argon as the shielding gas. This welding wire produces a stable arc, aesthetically pleasing weld formation, and is free from defects such as porosity, cracks, inclusions, and oxidation. The resulting high-entropy alloy wear-resistant coating can achieve a maximum hardness of 542HV. 0.5 Its hardness is 2.5 times higher than that of the base material, and it has excellent wear resistance, meeting the requirements for use.

[0052] Example 3

[0053] Step 1: First, clean the Fe-Co-Ni alloy strip with a mixture of NaOH and acetone. After cleaning, rinse with water and then use a mixed aqueous solution of HF and HNO3 for ultrasonic cleaning to obtain the cleaned Fe-Co-Ni alloy strip.

[0054] In step 1, the NaOH and acetone mixture used had a NaOH mass fraction of 15% and an acetone mass fraction of 85%. The HF and HNO3 mixed aqueous solution had a HF mass fraction of 5% and an HNO3 mass fraction of 35%. Ultrasonic cleaning was performed for 1.5 min at a frequency of 25 kHz.

[0055] Step 2: Prepare the mixture according to the mass percentages, with a total mass percentage of 100%, including Co: 17.7%, Cr: 15.5%, Ni: 17.7%, and Nb: 49.1%. Weigh out the various metal powders according to the mass percentages.

[0056] In step 2, the particle size of each raw material powder is no greater than 124 μm.

[0057] Step 3: Dry mix the various raw material powders heated in Step 2 in a mixer until they are evenly mixed to obtain core powder;

[0058] Step 4: The flux powder uniformly mixed in Step 3 is wrapped in Fe-Co-Ni alloy strip using a flux-cored wire forming machine, and the Fe-Co-Ni alloy strip is closed using a forming machine to obtain a 2.1mm diameter welding wire semi-finished product.

[0059] Step 5: The high-entropy alloy flux-cored welding wire precursor with a diameter of 2.1 mm obtained in Step 4 is subjected to a multi-pass cold drawing and diameter reduction die to obtain a welding wire with a diameter of 1.42 mm;

[0060] In step 5, the specific process of the multi-pass cold drawing and diameter reduction wire drawing die is as follows: the wire passes through wire drawing dies with diameters of 2.0mm, 1.9mm, 1.8mm, 1.7mm, 1.6mm, 1.5mm, and 1.42mm in sequence.

[0061] Step 6: Wipe the oil stains on the welding wire with a cotton cloth soaked in acetone or anhydrous ethanol. Finally, straighten the welding wire, coil it into a disc, and seal it in packaging using a wire drawing machine.

[0062] The welding process of the high-entropy alloy flux-cored welding wire prepared in Example 3 was as follows: Tungsten inert gas (TIG) welding was used, with a welding current of 170 A, a voltage of 15–20 V, a welding speed of 15 cm / min, and pure argon as the shielding gas. This welding wire produced a stable arc, aesthetically pleasing weld formation, and was free of defects such as porosity, cracks, inclusions, and oxidation. The resulting high-entropy alloy wear-resistant coating achieved a maximum hardness of 550 HV. 0.5 Its hardness is 2.5 times higher than that of the base material, and it has excellent wear resistance, meeting the requirements for use.

[0063] Example 4

[0064] Step 1: First, clean the Fe-Co-Ni alloy strip with a mixture of NaOH and acetone. After cleaning, rinse with water and then use a mixed aqueous solution of HF and HNO3 for ultrasonic cleaning to obtain the cleaned Fe-Co-Ni alloy strip.

[0065] In step 1, the NaOH and acetone mixture used has a NaOH mass fraction of 15% and an acetone mass fraction of 85%. The HF and HNO3 mixed aqueous solution has a HF mass fraction of 5% and an HNO3 mass fraction of 35%. Ultrasonic cleaning is performed for 1–2 minutes at a frequency of 20–30 kHz.

[0066] Step 2: Prepare the mixture according to the mass percentages, with a total mass percentage of 100%, including Co: 16.5%, Cr: 14.8%, Ni: 16.5%, and Nb: 52.2%. Weigh out the various metal powders according to the mass percentages.

[0067] In step 2, the particle size of each raw material powder is no greater than 124 μm.

[0068] Step 3: Dry mix the various raw material powders heated in Step 2 in a mixer until they are evenly mixed to obtain core powder;

[0069] Step 4: The flux powder uniformly mixed in Step 3 is wrapped in Fe-Co-Ni alloy strip using a flux-cored wire forming machine, and the Fe-Co-Ni alloy strip is closed using a forming machine to obtain a 2.1mm diameter welding wire semi-finished product.

[0070] Step 5: The high-entropy alloy flux-cored welding wire precursor with a diameter of 2.1 mm obtained in Step 4 is subjected to a multi-pass cold drawing and diameter reduction die to obtain a welding wire with a diameter of 1.42 mm;

[0071] In step 5, the specific process of the multi-pass cold drawing and diameter reduction wire drawing die is as follows: the wire passes through wire drawing dies with diameters of 2.0mm, 1.9mm, 1.8mm, 1.7mm, 1.6mm, 1.5mm, and 1.42mm in sequence.

[0072] Step 6: Wipe the oil stains on the welding wire with a cotton cloth soaked in acetone or anhydrous ethanol. Finally, straighten the welding wire, coil it into a disc, and seal it in packaging using a wire drawing machine.

[0073] The welding process of the high-entropy alloy flux-cored welding wire prepared in Example 4 was as follows: Tungsten inert gas (TIG) welding was used, with a welding current of 170 A, a voltage of 15–20 V, a welding speed of 15 cm / min, and pure argon as the shielding gas. This welding wire produced a stable arc, aesthetically pleasing weld formation, and was free of defects such as porosity, cracks, inclusions, and oxidation. The resulting high-entropy alloy wear-resistant coating achieved a maximum hardness of 586 HV. 0.5 Its hardness is 2.7 times higher than that of the base material, and its wear resistance is excellent, meeting the application requirements. Metallographic observation of the obtained cladding layer (e.g., ...) was performed. Figure 1 As shown), these are the lower and upper parts of the coating, respectively. From Figure 1 As can be seen, the lower part of the coating is mainly composed of columnar crystals, while the upper part is mainly composed of fine equiaxed crystals and cellular crystals. Based on comprehensive performance testing and monitoring of the welding process, the flux-cored welding wire prepared by this invention exhibits excellent process performance, strong adaptability to welding stainless steel surfaces, and a high-strength, wear-resistant cladding layer.

Claims

1. A high-entropy alloy flux-cored welding wire for wear-resistant coating of stainless steel, characterized in that, It consists of a solder coating and a flux core, wherein the flux core is composed of the following components by mass percentage: Co: 16.5%~18.8%, Cr: 14.8%~17.6%, Ni: 16.5%~18.8%, Nb: 42.4%~52.2%, and the sum of the percentages of the above components is 100%; the filling rate of the flux core is 38wt%~42wt%. The weld bead is an Fe-Co-Ni alloy strip; the composition of the Fe-Co-Ni alloy strip by mass percentage is: Si: ≤0.1%, Mn: ≤0.26%, Ni: 29.08%~30%, Co: 17.31%~18%, Cu: ≤0.011%, Cr: ≤0.006%, with the balance being Fe.

2. A method for preparing high-entropy alloy flux-cored welding wire for wear-resistant coating of stainless steel, characterized in that, The specific steps are as follows: Step 1: The Fe-Co-Ni alloy strip is cleaned sequentially with a mixture of NaOH and acetone, then with water, and finally ultrasonically cleaned with a mixed aqueous solution of HF and HNO3 to obtain the cleaned Fe-Co-Ni alloy strip. The NaOH and acetone mixture used has a NaOH mass fraction of 15% and an acetone mass fraction of 85%; the HF and HNO3 mixed aqueous solution has a HF mass fraction of 5% and an HNO3 mass fraction of 35%; the ultrasonic cleaning time is 1-2 min and the frequency is 20-30 kHz. Step 2: Weigh the following materials for the core according to their mass percentages: Co: 16.5%~18.8%, Cr: 14.8%~17.6%, Ni: 16.5%~18.8%, Nb: 42.4%~52.2%, with the sum of the mass percentages of the above materials being 100%. Step 3: Mix the heated raw material powders from Step 2 evenly in a mixer to obtain core powder; Step 4: The flux-cored powder uniformly mixed in Step 3 is wrapped in Fe-Co-Ni alloy strip using a flux-cored wire forming machine, and the Fe-Co-Ni alloy strip is closed using a forming machine to obtain a semi-finished welding wire. Step 5: The semi-finished welding wire is subjected to multiple cold drawing and diameter reduction dies to obtain the welding wire; Step 6: Wipe the oil stains on the welding wire with a cotton cloth soaked in acetone or anhydrous ethanol. Finally, straighten the welding wire, coil it into a disc, and seal it in packaging using a wire drawing machine. The composition of the Fe-Co-Ni alloy strip, by mass percentage, is as follows: Si: ≤0.1%, Mn: ≤0.26%, Ni: 29.08%~30%, Co: 17.31%~18%, Cu: ≤0.011%, Cr: ≤0.006%, with the balance being Fe.

3. The method for preparing high-entropy alloy flux-cored welding wire for wear-resistant coating of stainless steel according to claim 2, characterized in that, In step 2, the particle size of each raw material powder is no greater than 124 μm.

4. The method for preparing high-entropy alloy flux-cored welding wire for wear-resistant coating of stainless steel according to claim 2, characterized in that, In step 2, the specific process of the multi-pass cold drawing and diameter reduction wire drawing die is as follows: the wire passes through wire drawing dies with diameters of 2.0mm, 1.9mm, 1.8mm, 1.7mm, 1.6mm, 1.5mm, and 1.42mm in sequence.

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