CN104195362A - Preparation method of high-boron and wear-resistant alloy - Google Patents

Abstract

The invention discloses a method for preparing a high-boron corrosion-resistant alloy, which belongs to the technical field of zinc liquid corrosion wear materials. First, the particle size range of the powder is 140-200 mesh, and the mass fraction is respectively 45-50% ferroboron powder, 14-16% ferrochromium powder, 3-5% ferromolybdenum powder, 4-4.6% pure nickel powder, 1.5- 2.5% WC powder and 25-30% pure iron powder are evenly mixed, and laser cladding is carried out on the stainless steel base material by using a fiber laser and synchronous powder feeding method to obtain a high-boron material with no cracks, inclusions and pores on the surface and a smooth surface. Wear-resistant alloy laser cladding layer.

Description

A kind of preparation method of high boron wear-resistant alloy

technical field

The invention relates to a preparation method of a corrosion-resistant wear-resistant alloy, in particular to a preparation method of a high-boron wear-resistant alloy, which belongs to the technical field of corrosion materials.

Background technique

In the hot-dip galvanizing production line, key roll components such as sinking rolls, stabilizing rolls, and straightening rolls not only suffer from strong corrosion in the high-temperature molten zinc solution, but also the moving speed of the roll surface for conveying the steel strip is as high as 35-40m/s, which is extremely susceptible to wear and tear. Under the combined effect of these two aspects, surface damage such as pitting, pitting, wear marks, and zinc tumors is extremely prone to occur on the roll surface, resulting in frequent replacement of the above-mentioned components and reducing the operating rate of the hot-dip galvanizing equipment. In order to improve the high temperature corrosion and wear resistance of the material, the Chinese invention patent CN 101748354A discloses a spraying method of a zinc liquid corrosion and wear resistant composite coating, including WC-Co powder material, MoB-Co powder material and powder spraying The device is characterized in that the method comprises the following steps: step 1, pre-treating the surface of the substrate to be sprayed before spraying, using organic solvents for cleaning, preheating, dehumidification, degreasing and activation treatment; step 2, using the powder The spraying device sprays the WC-Co powder material on the surface of the substrate to be sprayed as a primer layer. The powder particle size of the WC-Co powder material is 25-65 μm, and the oxygen flow rate of the powder spraying device is set to 880-890 liters/minute, the kerosene flow rate is set to 0.35-0.40 liters/minute, the spraying distance is set to 300-390mm, the powder supply speed of thermal spraying is set to 60-100 grams/minute, and the obtained coating thickness is 0.15 -0.20mm; step 3, using the powder spraying device to spray the MoB-Co powder material on the surface of the WC-Co powder material coating as a working layer, and the powder particle size of the MoB-Co powder material 25-65 μm, the oxygen flow rate of the powder spraying device is set at 880-920 liters/minute, the kerosene flow rate is set at 0.40-0.45 liters/minute, the spraying distance is set at 300-390 mm, the powder supply speed of thermal spraying Set at 60-100 g/min, the obtained coating thickness is 0.07-0.10mm. Chinese invention patent CN 101215671B also discloses a liquid zinc corrosion resistant material and its manufacturing method. The chemical composition of the zinc liquid corrosion resistant material is (weight%): 0.6-0.8C, 4.0-7.0B, 4.0-6.0Cr , 4.0-7.0Mo, 2.0-5.0W, 0.3-0.6Si, 0.3-0.6Mn, S<0.05, P<0.05, and the balance is Fe. The anti-corrosion wear material of molten zinc is smelted in an electric furnace and molded by a casting method. The casting is subjected to rough machining after annealing, quenching at 980-1020°C and tempering at 520-580°C for finishing. The anti-corrosion and wear material of zinc liquid in the invention has high hardness at room temperature, reaching 62-65HRC, and the hardness at 500 DEG C also reaches 56-58HRC. The bending strength reaches 900-1100MPa. Chinese invention patent CN103769813A also discloses a manufacturing method of a high-hardness corrosion-resistant galvanized sinker roll, which includes the following steps: Step 1, sandblasting and roughening the sinker roll body before welding: spraying the cut sinker roll body sand, and then clean and decontaminate the sunken roller after sandblasting; Step 2, weld a layer of corrosion-resistant hardened layer with tungsten carbide as the hard phase and cobalt-based metal as the connecting phase on the surface of the sunken roller. The beneficial effect of the invention is: the surface corrosion-resistant material and the roll body base are welded, and the welding material used is to add tungsten carbide hard phase on the basis of the cobalt-based material, which can ensure the red hardness of the roll body surface and has Super wear resistance, the wear resistance of the welded layer structure is stronger than that of cemented carbide; the processing is simple, no large-scale equipment is needed, only simple welding equipment is required, there is no strict requirement on the roll body before processing, and the welded layer structure is dense , no pores, oxides and other inclusions, there is no space for zinc liquid corrosion. Chinese invention patent CN103741090A also discloses the spraying method of the surface coating of sinking roll and stabilizing roll, especially relates to a kind of spraying method of high powder feeding rate anti-high temperature corrosion and wear-resistant coating applied to the surface of sinking roll and stabilizing roll. The method is carried out according to the following steps: workpiece pretreatment, spraying operation, coating surface cleaning, roughness adjustment, hole sealing treatment, dynamic balance test inspection, inspection and packaging. The powder utilization rate is high during spraying, the powder feeding rate reaches 45%, the combination of the coating and the substrate is good, and the bonding strength is ≥70MPa; when spraying the WC-based coating, the WC particles after spraying are less oxidatively decomposed, and the bonding phase Co is also It is beneficial to the combination of particles in the coating and supplements the lack of coating toughness. The coating hardness HV1≥1050 ensures that the coating has high hardness and good toughness; the sealing treatment after coating spraying can further fill the coating The pores in the coating, the porosity is less than 0.5%, to prevent the corrosion medium from entering the corrosion workpiece through the pores of the coating. Chinese invention patent CN103233173A also discloses a sunken roller bushing and its preparation method. The chemical composition of the sunken roller bushing material is (mass fraction, %): 0.10‐0.25C, 2.0‐3.0B, 16.0‐18.0Mn, 2.0‐ 3.5Cr, 0.15‐0.30N, S<0.03, P<0.03, Fe balance. The shaft sleeve material of the invention can be produced by using an electric furnace, and has the characteristics of high hardness and strength, good toughness, corrosion resistance and wear resistance, etc., and the manufacturing process is simple and the production cost is low. Chinese invention patent CN02851597A also discloses an anti-abrasion sinking roller bushing and its manufacturing method. The specific composition and mass fraction % are as follows: 0.15‐0.28C, 3.0‐3.5B, 2.0‐2.5Cr, 9.5‐10.0W, 2.5‐ 3.0Mo, 0.65‐0.80Al, 1.20‐1.50Si, 0.25‐0.50Mn, 0.04‐0.08Y, 0.06‐0.10Ti, 0.06‐0.10Nb, 0.03‐0.06Ca, 0.05‐0.08Mg, 0.08‐0.12K, S< 0.04, P<0.05, the balance being Fe. The anti-abrasion sinking roller sleeve of the invention is smelted in an electric furnace, formed by casting, and finished after quenching and tempering. The invention has high hardness of the anti-abrasion sinking roller sleeve, good wear resistance, toughness and zinc liquid corrosion resistance. Chinese invention patent CN102206792A also discloses a sunken roll of low alloy material, the composition of the material used is C0.04‐0.06, Si0.4‐0.8, Mn3.5‐4, P, S≤0.02, Cr12-13, Ni0.7-1.0, Mo0.8-1.2, and the rest are Fe and unavoidable impurities; the sinking roll is prepared according to the following steps: 1) carbon rod, metal silicon, metal manganese, nickel plate, chromium Iron, metal molybdenum and iron are used as raw materials. After drying, put them into an intermediate frequency induction furnace. The order of adding is to add a certain amount of iron and carbon rods first, then add nickel plate, metal manganese, and metal molybdenum after melting, and finally add a certain amount of ferrochromium. , when the smelting temperature reaches 1560-1580°C, add an appropriate amount of metal silicon; wherein the ratio of the raw materials is based on 1000kg of materials, carbon rod 0.1-0.12kg, metal silicon 2-10kg, metal manganese 30-45kg, nickel plate 5‐10kg, ferrochrome 169‐215kg, metal molybdenum 5‐15kg, iron balance, of which ferrochrome is iron with a chromium content of 65%; Take it out after cooling; 3) Take out the steel pipe and quickly put it into the furnace tube to keep warm and cool it below 100°C and take it out. After taking it out, the steel pipe is normalized. The normalizing condition is 980-1000°C. Process the size of the steel cylinder, process the steel cylinder and the roll neck assembly welding at both ends of the sinking roller, preheat 200-250°C before welding, and use 410H as the welding material; anneal treatment after the overall welding is completed, the annealing condition is 700°C, and the thickness of the steel pipe is 25mm heat preservation for 3 hours; 4) After the overall annealing, the sunken roller is processed and meets the requirements of the drawing, and the surface is inspected for liquid penetration. After the dynamic balance test is passed, it is transferred to the customer for use. Chinese invention patent CN102128208A also discloses a method for preparing a sinking roller sleeve with high bonding strength, which is characterized in that the steps of the method include the following points: 1. Machining the stainless steel substrate; 2. Machining the ceramic ring; 3. Ceramic surface Metallization, the metallization layer on the surface of ceramics is 50-400 microns, containing metal or non-metal, and binders and additives, the raw material is either elemental powder, or a combination of these elemental powders, wherein the elemental powder is Co , Si, Cu, Cr, B, and W, the binder is NaCl and SnCl4 mixed by mass 2:3, the auxiliary agent is polyethylene glycol and rosin mixed by mass 1:1, and the mass content of Co Between 40% and 60%, the mass content of other metal elements is not more than 10%; 4. Brazing connects the two parts of the stainless steel substrate and the ceramic ring; 5. Machining to the designed size.

However, the above-mentioned anti-abrasion alloys may have coarse structure, high brittleness, easy peeling off during use, or poor high-temperature anti-abrasion performance and the like.

Contents of the invention

The purpose of the present invention is to overcome the deficiencies in the prior art, and provide a high-boron, wear-resistant alloy with a large amount of Fe ₂ B phases, which is fine, dense, and excellent in corrosion and wear resistance to molten zinc, by using a laser cladding method.

The object of the present invention can be realized through the following process steps:

① First, the particle size range of the powder is 140-200 mesh, and the mass fraction is 45-50% ferro-boron powder, 14-16% ferro-chromium powder, 3-5% ferro-molybdenum powder, 4-4.6% pure nickel powder, 1.5% ～2.5% WC powder and 25～30% pure iron powder are mixed evenly.

②Use the fiber laser and synchronous powder feeding method to carry out laser cladding on the stainless steel base material with the uniformly mixed powder, the powder feeding rate is 18-20g/min, the laser power is 3.0-4.5KW, and the scanning speed is 8 -10mm/s, the number of cladding layers is 8-10 layers. Finally, the laser cladding layer of high boron wear-resistant alloy with no cracks, inclusions and pores on the surface and smooth surface can be obtained.

As mentioned above, the chemical composition mass fraction of ferroboron powder is: 19.0-21.0% B, ≤0.5% C, ≤2% Si, ≤0.5% Al, ≤0.01% S, ≤0.1% P, and the balance Fe.

As mentioned above, the chemical composition mass fraction of ferrochrome powder is: 60-65% Cr, 6.8-7.5% C, ≤3.0% Si, ≤0.05% S, ≤0.06% P, and the balance Fe.

As mentioned above, the chemical composition mass fraction of molybdenum iron powder is: 66.0～72.0% Mo, ≤1.5% Si, ≤0.10% S, ≤0.05% P, ≤0.10% Sb, ≤0.50% Sn, and the balance Fe.

The laser cladding method of the present invention prepares a high-boron wear-resistant alloy. The alloy powder is mainly composed of ferroboron powder, pure iron powder and ferrochrome powder, wherein 45-50% of the mass fraction of ferroboron powder is added, mainly by using the power input by the laser , a large amount of Fe ₂ B phase is obtained in the cladding layer. Fe ₂ B has the characteristics of high hardness, good wear resistance and excellent resistance to zinc liquid corrosion, and is an ideal phase resistant to zinc liquid corrosion. The addition of ferrochrome powder with a mass fraction of 14-16% mainly uses the combination of chromium and carbon to obtain a high-hardness Cr ₇ C ₃ phase, which is beneficial to improving the wear resistance of the alloy. In addition, the addition of molybdenum iron powder with a mass fraction of 3-5% is mainly to use molybdenum to dissolve in the matrix to increase the high-temperature hardness of the matrix. The increase in the high-temperature hardness of the matrix can prevent the occurrence of Fe ₂ B phase and Cr ₇ C ₃ phase Peeling off, so as to improve the alloy's ability to resist high temperature abrasion. Adding 1.5-2.5% WC powder can improve the wear resistance. On this basis, 4-4.6% pure nickel powder is also added, mainly because nickel is solid-dissolved in the matrix, which is beneficial to improve the plasticity of the matrix.

In the process of preparing the high-boron wear-resistant alloy by the laser cladding method of the present invention, the uniformly mixed alloy powder is used for laser cladding on the stainless steel base material by using a fiber laser and a synchronous powder feeding method. When the powder feeding rate is controlled at 18-20g/min, the laser power is controlled at 3.0-4.5KW, the scanning speed is controlled at 8-10mm/s, the number of cladding layers is controlled at 8-10 layers, and finally the surface without cracks, inclusions and pores and smooth surface can be obtained. High hardness (more than 850HV), high boron wear-resistant alloy laser cladding layer with good corrosion and wear resistance in zinc liquid.

Compared with the prior art, the present invention has the following advantages:

1) The high-boron wear-resistant alloy of the present invention is prepared by laser cladding method, which overcomes the shortcomings of the traditional casting method to prepare high-boron alloy borides with large size and easy cracking during casting and use, and also overcomes the complex process of powder metallurgy method , high cost;

2) The amount of Fe ₂ B phase in the high-boron corrosion-resistant alloy of the present invention reaches 55-55% (volume fraction), and has excellent resistance to corrosion and wear of molten zinc at high temperatures. Under the same corrosion and wear conditions, it is resistant to corrosion and wear of molten zinc The capacity is 6-8 times higher than that of 316L stainless steel.

Detailed ways

The present invention will be described in further detail below in conjunction with the examples, but the present invention is not limited to the following examples.

Example 1:

The high-boron wear-resistant alloy is prepared by laser cladding, and the specific preparation process steps are:

① First, the particle size range of the powder is 140-200 mesh, and the mass fraction is 45% ferroboron powder (the chemical composition mass fraction of ferroboron powder is: 19.04% B, 0.27% C, 1.33% Si, 0.20% Al, 0.008 %S, 0.063%P, balance Fe), 16% ferrochrome powder (mass fraction of chemical composition of ferrochrome powder is: 62.15%Cr, 7.34%C, 2.07%Si, 0.028%S, 0.035%P, balance Fe), 3% molybdenum iron powder (the chemical composition mass fraction of molybdenum iron powder is: 69.38% Mo, 0.71% Si, 0.056% S, 0.041% P, 0.034% Sb, 0.26% Sn, the balance Fe), 4.6% Mix pure nickel powder, 1.5% WC powder and 29.9% pure iron powder evenly.

②Use IPG 6kW fiber laser to carry out laser cladding on the 316L stainless steel base material by using the IPG 6kW fiber laser and synchronous powder feeding method. The powder feeding rate is 18g/min, the laser power is 3.0KW, and the scanning speed is 8mm/min. s, the number of cladding layers is 8 layers. Finally, the average hardness reaches 873.8HV, the surface is free of cracks, inclusions and pores, and the surface is smooth and high boron wear-resistant alloy laser cladding layer.

Example 2:

The high-boron wear-resistant alloy is prepared by laser cladding, and the specific preparation process steps are:

① First, the particle size range of the powder is 140-200 mesh, and the mass fraction is 50% ferroboron powder (the chemical composition mass fraction of ferroboron powder is: 20.84% B, 0.25% C, 0.87% Si, 0.20% Al, 0.006 %S, 0.071%P, balance Fe), 14% ferrochromium powder (mass fraction of chemical composition of ferrochrome powder is: 61.42%Cr, 7.10%C, 2.37%Si, 0.038%S, 0.045%P, balance Fe), 5% ferromolybdenum powder (the chemical composition mass fraction of ferromolybdenum powder is: 67.88% Mo, 0.92% Si, 0.063% S, 0.036% P, 0.037% Sb, 0.15% Sn, the balance Fe), 4% Mix pure nickel powder, 2% WC powder and 25% pure iron powder evenly.

②Use IPG 6kW fiber laser to carry out laser cladding on the 316L stainless steel base material by using IPG 6kW fiber laser and synchronous powder feeding method. The powder feeding rate is 19g/min, the laser power is 3.5KW, and the scanning speed is 9mm/min. s, the number of cladding layers is 9 layers. Finally, the average hardness reaches 892.0HV, the surface has no cracks, inclusions and pores, and the laser cladding layer of high boron wear-resistant alloy with smooth surface can be obtained.

Example 3:

The high-boron wear-resistant alloy is prepared by laser cladding, and the specific preparation process steps are:

① First, the particle size range of the powder is 140-200 mesh, and the mass fraction is 48% boron iron powder (the chemical composition mass fraction of boron iron powder is: 20.14% B, 0.38% C, 1.15% Si, 0.33% Al, 0.007 %S, 0.052%P, balance Fe), 15% ferrochromium powder (mass fraction of chemical composition of ferrochrome powder is: 64.17%Cr, 6.99%C, 2.34%Si, 0.041%S, 0.046%P, balance Fe), 4% ferromolybdenum powder (the chemical composition mass fraction of ferromolybdenum powder is: 69.50% Mo, 1.04% Si, 0.075% S, 0.048% P, 0.067% Sb, 0.38% Sn, the balance Fe), 4.3% Mix pure nickel powder, 2.5% WC powder and 26.2% pure iron powder evenly.

②Use IPG 6kW fiber laser to carry out laser cladding on the 316L stainless steel base material by using the IPG 6kW fiber laser and synchronous powder feeding method. The powder feeding rate is 20g/min, the laser power is 4.5KW, and the scanning speed is 10mm/min. s, the number of cladding layers is 10 layers. Finally, the average hardness reaches 883.1HV, the surface is free of cracks, inclusions and pores, and the surface is smooth and high-boron wear-resistant alloy laser cladding layer.

The amount of Fe2B phase in the high-boron anti-corrosion alloy of the present invention reaches 55-55% (volume fraction), has excellent high-temperature zinc liquid corrosion and wear resistance, and under the same corrosion and wear conditions, its zinc liquid corrosion and wear resistance is better than that of 316L stainless steel Increased by 6 to 8 times. The high-boron wear-resistant alloy of the present invention is prepared by laser cladding, which overcomes the disadvantages of the traditional casting method that the borides of the high-boron alloy are large in size and easy to crack during casting and use, and also overcomes the complex process and cost of the powder metallurgy method. High deficiency, in the field of hot-dip galvanizing has a good prospect of popularization and application.

Claims (5)

1. A method for preparing a high boron wear-resistant alloy, characterized in that, the laser cladding method is used to prepare, and the specific process steps are: ① First, the particle size range of the powder is 140-200 mesh, and the mass fraction is 45-50% ferro-boron powder, 14-16% ferro-chromium powder, 3-5% ferro-molybdenum powder, 4-4.6% pure nickel powder, 1.5% ～2.5% WC powder and 25～30% pure iron powder are mixed evenly; ②Use the fiber laser and synchronous powder feeding method to carry out laser cladding on the stainless steel base material with the uniformly mixed powder, the powder feeding rate is 18-20g/min, the laser power is 3.0-4.5KW, and the scanning speed is 8 -10mm/s, the number of cladding layers is 8-10 layers; finally, a high boron wear-resistant alloy laser cladding layer with no cracks, inclusions and pores on the surface and a smooth surface can be obtained. 2. According to the preparation method of the high-boron wear-resistant alloy according to claim 1, it is characterized in that the chemical composition mass fraction of ferroboron powder is: 19.0-21.0% B, ≤0.5% C, ≤2% Si, ≤0.5% Al, ≤0.01% S, ≤0.1% P, balance Fe. 3. According to the preparation method of the high-boron wear-resistant alloy according to claim 1, it is characterized in that the chemical composition mass fraction of the ferrochrome powder is: 60-65% Cr, 6.8-7.5% C, ≤3.0% Si, ≤0.05 %S, ≤0.06%P, balance Fe. 4. According to the preparation method of the high-boron corrosion-resistant alloy described in claim 1, it is characterized in that the chemical composition mass fraction of molybdenum-iron powder is: 66.0～72.0% Mo, ≤1.5% Si, ≤0.10% S, ≤0.05% P, ≤0.10% Sb, ≤0.50% Sn, balance Fe. 5. The high boron wear-resistant alloy prepared according to any method of claims 1-4.