Preparation method of a high-strength stainless steel flux-cored wire

Abstract

The present invention relates to the field of welding technology, specifically a preparation method of a high-strength stainless steel flux-cored wire; by defining the composition of the flux core and the steel strip of the stainless steel flux-cored wire, and performing surface treatment on the prepared stainless steel flux-cored wire, a stainless steel flux-cored wire with a micro-nano structure on the surface, dust-proof and easy to clean, is obtained, improving the surface dust removal problem while increasing the strength of the flux-cored wire, and improving the cleanliness of the weld structure, thereby densifying it; using low-cost nitrogen to replace part of the nickel element, a welding material for welding superalloys with corrosion resistance not lower than that of nickel-based flux-cored wires is prepared; using the nano-composite electroplating technology, a titanium dioxide-reinforced Cu-Sn-Zn nano-composite coating is prepared by electroplating. The combination of tin and zinc can endow the coating with good corrosion resistance and excellent weldability. Using the femtosecond laser processing technology, a micro-nano structure surface is prepared, thus greatly improving the self-cleaning property of the surface of the stainless steel flux-cored wire.

Description

Technical Field

[0001] The present invention relates to the technical field of welding, and specifically to a preparation method of a high-strength stainless steel flux-cored wire. Background Art

[0002] Welding technology is a processing technology between materials. With the progress of technology, welding technology is moving towards automation and high efficiency. Flux-cored wire is a kind of welding material with characteristics such as adjustable composition and high deposition efficiency, which effectively promotes the transformation of welding technology. Flux-cored wire is formed by filling flux powder inside and covering it with a steel strip. Compared with other welding materials, flux-cored wire has advantages such as high output and easy design of flux composition.

[0003] Stainless steel flux-cored wire generally rolls a steel strip into a U-shaped cross-section shape, and then adds welding powder to the U-shaped steel strip and draws it into flux-cored wires of different specifications. However, the existing stainless steel flux-cored wire has the following problems during dust removal treatment: The existing dust removal equipment for flux-cored wire takes a long time to replace the dry wiping cloth, and the drawing powder on the surface of the flux-cored wire cannot be completely wiped off. After water washing, the residual water on the surface of the flux-cored wire cannot be completely cleaned, which affects the oiling quality of the flux-cored wire and reduces the quality of the flux-cored wire. Summary of the Invention

[0004] The purpose of the present invention is to provide a preparation method of a high-strength stainless steel flux-cored wire to solve the problems in the prior art.

[0005] To solve the above technical problems, the present invention provides the following technical solutions:

[0006] A preparation method of a high-strength stainless steel flux-cored wire includes the following steps:

[0007] S1: Prepare flux powder, and reserve it after drying;

[0008] S2: Fill the flux powder into the steel strip, and after drawing, obtain a flux-cored wire substrate;

[0009] S3: Electroplate a nickel pre-coating on the surface of the flux-cored wire substrate;

[0010] S4: Perform femtosecond laser processing on the surface of the nickel pre-coating;

[0011] S5: Electroplate a composite titanium dioxide layer on the laser-treated surface to obtain a high-strength stainless steel flux-cored wire.

[0012] Further, in terms of mass percentage, the composition of the flux powder is: nickel 7-8%, chromium 27-28%, molybdenum 3.4-3.5%, tungsten 2.1%-2.8%, nitrogen 0.14-0.2%, manganese 0.8-1%, silicon 0.9-0.11%, and the balance is iron.

[0013] Furthermore, the flux-cored powder composition includes nickel powder, chromium powder, molybdenum powder, high-nitrogen ferrochrome, ferrosilicon metal or alloy powder, and mineral powder and compounds participating in slag formation and stabilizing the arc, such as rutile, potassium titanate, and quartz;

[0014] The main function of nickel is to promote the formation of the austenite phase. Adding sufficient nickel elements can expand the austenite phase region, making austenite remain stable at room temperature or lower temperatures. Moreover, nickel is not a strong carbide-forming element and does not promote the formation of intermetallic compounds; in a corrosive environment, chromium forms a dense and stable chromium oxide film to prevent the continuation of the corrosion process. It is a ferrite-forming element that can stabilize the ferrite structure. At the same time, chromium is also a strong carbide and nitride-forming element, mainly existing in the forms of Cr23C6 and Cr2N; molybdenum improves the high-temperature strength of duplex stainless steel and enhances the corrosion resistance of stainless steel, especially the resistance to pitting corrosion and crevice corrosion. However, molybdenum is a ferrite-forming element that will promote the formation and retention of ferrite in stainless steel;

[0015] Nitrogen is an important solid-solution strengthening element that can improve the strength of the deposited metal of stainless steel welding wire. At the same time, nitrogen is a strong austenitizing element and can also improve the resistance of the deposited metal to pitting corrosion and crevice corrosion. Usually, metal nitrides are added to the welding wire powder to transfer nitrogen elements to the deposited metal; introducing silicon can control the deoxidation during the welding process and improve the fluidity of the molten pool, thereby improving the forming quality of the weld. However, silicon elements can form various silicides with iron and chromium, having a tendency to embrittle the structure; quartz and zircon sand are added to the flux-cored powder. Silicon oxide will undergo a reduction reaction during the welding process to transfer silicon elements to the deposited metal of the welding wire.

[0016] Furthermore, by mass percentage, the composition of the steel strip is: chromium 18%, silicon 0.15%, manganese 0.13%, nickel 49%, carbon 0.02%, molybdenum 3.2%, aluminum 0.6%, titanium 1.01%, boron 0.002%, niobium 5.2%, and the balance is iron.

[0017] Furthermore, the working conditions of the nickel pre-plating layer are: the electroplating temperature is 55°C, the current density is 0.2 A / cm 2 , the electroplating time is 15 min, and the rotation speed of the stirrer is 500 r / min.

[0018] Furthermore, the composition of the nickel plating solution used for the nickel pre-plating layer is: using deionized water as the solvent, in which nickel sulfate is 300 g / L, nickel chloride is 45 g / L, and boric acid is 40 g / L.

[0019] Furthermore, the working conditions for electroplating the composite titanium dioxide layer are: the temperature is controlled at 30 - 35°C, the stirring speed is 300 r / min, the electroplating time is 15 min, and the current density is 0.2 A / cm 2 .

[0020] Further, the composition of the plating solution used for electroplating the composite titanium dioxide layer is as follows: using deionized water as the solvent, including 30 g / L of copper sulfate, 3 g / L of stannous chloride, 8 g / L of zinc sulfate, 250 g / L of potassium pyrophosphate, 8 g / L of sodium dihydrogen phosphate, 22 g / L of potassium citrate, 22 g / L of potassium sodium tartrate, 0.04 g / L of saccharin, 2 - 4 g / L of titanium dioxide, and 10 - 18 mL / L of titanium dioxide sol.

[0021] Further, the preparation of the titanium dioxide sol includes the following steps: mixing and stirring diethanolamine and ethanol, adding tetrabutyl titanate, adding a mixed solution of ethanol and distilled water, and stirring to obtain the titanium dioxide sol.

[0022] Further, the working conditions of the laser processing are as follows: the laser pulse width is 100 fs, the central wavelength is 800 nm, the repetition frequency is 1 kHz, the laser scanning line spacing is 20 μm, and the laser scanning speed is 200 mm / s.

[0023] Further, in the preparation of the flux cored powder, the metal powder is prone to moisture absorption, and defects such as pores and cracks are likely to occur in the surfacing of the flux cored wire. Therefore, the powder needs to be dried. The metal powder is filtered through a 120 - mesh sieve to remove larger particles, and then mixed and dried. The drying parameters are: temperature 150 °C, heat preservation time 4 h, and cooling with the furnace.

[0024] The beneficial effects of the present invention:

[0025] The present invention provides a preparation method of a high - strength stainless - steel flux cored wire. By limiting the composition of the flux core and the steel strip of the stainless - steel flux cored wire, and performing surface treatment on the prepared stainless - steel flux cored wire, a stainless - steel flux cored wire with a micro - nano structure on the surface, dust - proof and easy to clean, is obtained. While improving the strength of the flux cored wire, the surface dust removal problem is improved, and the cleanliness of the weld metal structure is increased, thereby making it densified.

[0026] Nickel element has a face - centered cubic structure, and its crystal stability enables it to resist corrosion in various environments. Therefore, nickel - based flux cored wires are widely used in fields such as petrochemical industry, aerospace, thermal power, and gas turbines. However, the nickel content in nickel - based flux cored wires is as high as over 60%, and the annual consumption is huge. Although Co and C can also replace Ni to stabilize austenite, Co will cause allergic reactions, while C will enhance the formation tendency of carbides and reduce the corrosion resistance. Therefore, in the present invention, low - cost nitrogen is used to replace part of the nickel element to prepare a welding material for superalloy welding with corrosion performance not lower than that of nickel - based flux cored wires;

[0027] To improve the rust resistance, wear resistance, and dust removal and easy cleaning properties of stainless steel flux-cored wires, surface coating treatment is carried out on the steel flux-cored wires. The nickel pre-coating enhances the bonding force between the composite titanium dioxide layer and the stainless steel flux-cored wire. Using the nano-composite electroplating technology, a titanium dioxide-reinforced Cu-Sn-Zn nano-composite coating is prepared by electroplating. The combination of tin and zinc can endow the coating with good corrosion resistance and excellent weldability. Using the femtosecond laser processing technology, a micro-nano structure surface is prepared, thereby greatly improving the self-cleaning property of the surface of the stainless steel flux-cored wire, and thus improving the welding performance. Detailed implementation manners

[0028] The following will combine the embodiments of the present invention to clearly and completely describe the technical solutions in the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments in the present invention, all other embodiments obtained by those of ordinary skill in the art without making creative efforts belong to the scope protected by the present invention.

[0029] It should be noted that if there are directional indications such as up, down, left, right, front, back... in the embodiments of the present invention, the directional indications are only used to explain the relative position relationship and movement conditions between components in a specific posture. If the specific posture changes, the directional indications will also change accordingly. In addition, the technical solutions between the various embodiments can be combined with each other, but it must be based on the fact that those of ordinary skill in the art can implement them. When the combination of technical solutions results in contradictions or cannot be implemented, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0030] The following further details the technical solutions of the present invention in combination with specific embodiments. It should be understood that the following embodiments are only used to explain the present invention and are not used to limit the present invention.

[0031] Embodiment 1

[0032] A preparation method of a high-strength stainless steel flux-cored wire includes the following steps:

[0033] S1: Prepare the flux powder and keep it for use after drying;

[0034] By mass percentage, the composition of the flux powder is: nickel 7%, chromium 27%, molybdenum 3.4%, tungsten 2.1%, nitrogen 0.14%, manganese 0.8%, silicon 0.9%, and the balance is iron; the drying working conditions are: temperature 150°C, heat preservation time 4h, and furnace cooling.

[0035] S2: Fill the flux powder into the steel strip, and after drawing, obtain the flux-cored wire substrate;

[0036] The composition of the steel strip, by mass percentage, is as follows: chromium 18%, silicon 0.15%, manganese 0.13%, nickel 49%, carbon 0.02%, molybdenum 3.2%, aluminum 0.6%, titanium 1.01%, boron 0.002%, niobium 5.2%, and the balance is iron;

[0037] The working conditions for drawing are as follows: the feeding speed of the steel strip is 0.3 m / s, the number of drawing passes is 7, the powder filling rate is 24%, and the diameter of the flux-cored wire base material is 1 mm;

[0038] S3: Electroplate a nickel pre-plating layer on the surface of the flux-cored wire base material;

[0039] The working conditions for the nickel pre-plating layer are as follows: the electroplating temperature is 55 °C, the current density is 0.2 A / cm 2 , the electroplating time is 15 min, and the stirrer rotation speed is 500 r / min; the composition of the nickel plating solution used for the nickel pre-plating layer is as follows: using deionized water as the solvent, where nickel sulfate is 240 g / L, nickel chloride is 36 g / L, and boric acid is 32 g / L;

[0040] S4: Perform femtosecond laser processing on the surface of the nickel pre-plating layer;

[0041] The working conditions for the laser processing are as follows: the laser pulse width is 100 fs, the central wavelength is 800 nm, the repetition frequency is 1 kHz, the laser scanning line spacing is 20 μm, and the laser scanning speed is 200 mm / s;

[0042] S5: Electroplate a composite titanium dioxide layer on the laser-treated surface to obtain a high-strength stainless steel flux-cored wire;

[0043] The working conditions for electroplating the composite titanium dioxide layer are as follows: the temperature is controlled at 30 °C, the stirring speed is 300 r / min, the electroplating time is 15 min, and the current density is 0.2 A / cm 2 ; the composition of the plating solution used for electroplating the composite titanium dioxide layer is as follows: using deionized water as the solvent, where copper sulfate is 30 g / L, stannous chloride is 3 g / L, zinc sulfate is 8 g / L, potassium pyrophosphate is 250 g / L, sodium dihydrogen phosphate is 8 g / L, potassium citrate is 22 g / L, sodium potassium tartrate is 22 g / L, saccharin is 0.04 g / L, titanium dioxide is 2 g / L, and titanium dioxide sol is 10 mL / L;

[0044] The preparation of the titanium dioxide sol includes the following steps: Mix 3.1 g of diethanolamine and 35 mL of ethanol and stir for 30 min, add 8.68 mL of tetrabutyl titanate, add a mixture of 4.5 mL of ethanol and 0.45 mL of distilled water, and stir for 1 h to obtain the titanium dioxide sol.

[0045] Example 2

[0046] A method for preparing a high-strength stainless steel flux-cored wire, comprising the following steps:

[0047] S1: Prepare the flux-cored powder, and set it aside after drying.

[0048] By mass percentage, the composition of the flux-cored powder is: nickel 7.5%, chromium 27.5%, molybdenum 3.45%, tungsten 2.6%, nitrogen 0.18%, manganese 0.9%, silicon 0.10%, and the balance is iron; the drying working conditions are: temperature 150°C, heat preservation time 4h, furnace cooling.

[0049] S2: Fill the flux-cored powder into the steel strip, and obtain the flux-cored wire base material after drawing.

[0050] By mass percentage, the composition of the steel strip is: chromium 18%, silicon 0.15%, manganese 0.13%, nickel 49%, carbon 0.02%, molybdenum 3.2%, aluminum 0.6%, titanium 1.01%, boron 0.002%, niobium 5.2%, and the balance is iron.

[0051] The working conditions for drawing are: the feeding speed of the steel strip is 0.3m / s, the number of drawing times is 8 times, the powder filling rate is 25%, and the diameter of the flux-cored wire base material is 1.5mm.

[0052] S3: Electroplate a nickel pre-plating layer on the surface of the flux-cored wire base material.

[0053] The working conditions for the nickel pre-plating layer are electroplating temperature 55°C, current density 0.2A / cm 2 , electroplating time 15min, stirrer rotation speed 500r / min; the composition of the nickel plating solution used for the nickel pre-plating layer is: using deionized water as the solvent, in which nickel sulfate is 240g / L, nickel chloride is 36g / L, and boric acid is 32g / L.

[0054] S4: Perform femtosecond laser processing on the surface of the nickel pre-plating layer.

[0055] The working conditions for the laser processing are: laser pulse width 100fs, central wavelength 800nm, repetition frequency 1kHz, laser scanning line spacing 20μm, laser scanning speed 200mm / s.

[0056] S5: Electroplate a composite titanium dioxide layer on the surface after laser treatment to obtain a high-strength stainless steel flux-cored wire.

[0057] The working conditions for electroplating the composite titanium dioxide layer are: temperature controlled at 33°C, stirring speed at 300r / min, electroplating time 15min, current density 0.2A / cm 2; The composition of the plating solution used for electroplating the composite titanium dioxide layer is as follows: using deionized water as the solvent, including 30 g / L of copper sulfate, 3 g / L of stannous chloride, 8 g / L of zinc sulfate, 250 g / L of potassium pyrophosphate, 8 g / L of sodium dihydrogen phosphate, 22 g / L of potassium citrate, 22 g / L of sodium potassium tartrate, 0.04 g / L of saccharin, 3 g / L of titanium dioxide, and 15 mL / L of titanium dioxide sol;

[0058] The preparation of the titanium dioxide sol includes the following steps: Mix 3.1 g of diethanolamine and 35 mL of ethanol, stir for 30 min, add 8.68 mL of tetrabutyl titanate, then add a mixture of 4.5 mL of ethanol and 0.45 mL of distilled water, and stir for 1.5 h to obtain the titanium dioxide sol.

[0059] Example 3

[0060] A preparation method of a high-strength stainless steel flux-cored wire includes the following steps:

[0061] S1: Prepare the flux-cored powder, and reserve it after drying;

[0062] By mass percentage, the composition of the flux-cored powder is: 8% nickel, 28% chromium, 3.5% molybdenum, 2.8% tungsten, 0.2% nitrogen, 1% manganese, 0.11% silicon, and the balance is iron; the drying working conditions are: temperature 150 °C, heat preservation time 4 h, and furnace cooling;

[0063] S2: Fill the flux-cored powder into the steel strip, and obtain the flux-cored wire base material after drawing;

[0064] By mass percentage, the composition of the steel strip is: 18% chromium, 0.15% silicon, 0.13% manganese, 49% nickel, 0.02% carbon, 3.2% molybdenum, 0.6% aluminum, 1.01% titanium, 0.002% boron, 5.2% niobium, and the balance is iron;

[0065] The working conditions of drawing are: the feeding speed of the steel strip is 0.3 m / s, the number of drawing times is 8 times, the powder filling rate is 26%, and the diameter of the flux-cored wire base material is 2 mm;

[0066] S3: Electroplate a nickel pre-plating layer on the surface of the flux-cored wire base material;

[0067] The working conditions of the nickel pre-plating layer are electroplating temperature 55 °C, current density 0.2 A / cm 2 , electroplating time 15 min, stirrer rotation speed 500 r / min; the composition of the nickel plating solution used for the nickel pre-plating layer is: using deionized water as the solvent, including 240 g / L of nickel sulfate, 36 g / L of nickel chloride, and 32 g / L of boric acid;

[0068] S4: Perform femtosecond laser processing on the surface of the nickel pre-plating layer;

[0069] The working conditions for laser processing are as follows: the laser pulse width is 100 fs, the central wavelength is 800 nm, the repetition frequency is 1 kHz, the laser scanning line spacing is 20 μm, and the laser scanning speed is 200 mm / s;

[0070] S5: Electroplate a composite titanium dioxide layer on the surface after laser treatment to obtain a high-strength stainless steel flux-cored wire;

[0071] The working conditions for electroplating the composite titanium dioxide layer are as follows: the temperature is controlled at 35 °C, the stirring speed is 300 r / min, the electroplating time is 15 min, and the current density is 0.2 A / cm 2 ; The composition of the plating solution used for electroplating the composite titanium dioxide layer is as follows: using deionized water as the solvent, including 30 g / L of copper sulfate, 3 g / L of stannous chloride, 8 g / L of zinc sulfate, 250 g / L of potassium pyrophosphate, 8 g / L of sodium dihydrogen phosphate, 22 g / L of potassium citrate, 22 g / L of potassium sodium tartrate, 0.04 g / L of saccharin, 4 g / L of titanium dioxide, and 18 mL / L of titanium dioxide sol;

[0072] The preparation of titanium dioxide sol includes the following steps: Mix 3.1 g of diethanolamine and 35 mL of ethanol and stir for 30 min, then add 8.68 mL of tetrabutyl titanate, and then add a mixture of 4.5 mL of ethanol and 0.45 mL of distilled water, and stir for 2 h to obtain titanium dioxide sol.

[0073] Comparative Example 1

[0074] Taking Example 3 as the control group, no nickel pre-plating treatment was carried out, and other processes were normal.

[0075] A method for preparing a high-strength stainless steel flux-cored wire includes the following steps:

[0076] S1: Prepare the flux powder and set it aside after drying;

[0077] In terms of mass percentage, the composition of the flux powder is as follows: nickel 8%, chromium 28%, molybdenum 3.5%, tungsten 2.8%, nitrogen 0.2%, manganese 1%, silicon 0.11%, and the balance is iron; the working conditions for drying are: temperature 150 °C, heat preservation time 4 h, and furnace cooling;

[0078] S2: Fill the flux powder into the steel strip, and after drawing, obtain the flux-cored wire base material;

[0079] In terms of mass percentage, the composition of the steel strip is as follows: chromium 18%, silicon 0.15%, manganese 0.13%, nickel 49%, carbon 0.02%, molybdenum 3.2%, aluminum 0.6%, titanium 1.01%, boron 0.002%, niobium 5.2%, and the balance is iron;

[0080] The working conditions for drawing are as follows: the feeding speed of the steel strip is 0.3 m / s, the number of drawing passes is 8, the powder filling rate is 26%, and the diameter of the flux-cored wire base material is 2 mm;

[0081] S3: Perform femtosecond laser processing on the surface;

[0082] The working conditions for laser processing are as follows: the laser pulse width is 100 fs, the central wavelength is 800 nm, the repetition frequency is 1 kHz, the laser scanning line spacing is 20 μm, and the laser scanning speed is 200 mm / s;

[0083] S4: Electroplate a composite titanium dioxide layer on the surface after laser treatment to obtain a high-strength stainless steel flux-cored wire;

[0084] The working conditions for electroplating the composite titanium dioxide layer are as follows: the temperature is controlled at 35 °C, the stirring speed is 300 r / min, the electroplating time is 15 min, and the current density is 0.2 A / cm 2 ; The composition of the plating solution used for electroplating the composite titanium dioxide layer is: using deionized water as the solvent, including 30 g / L of copper sulfate, 3 g / L of stannous chloride, 8 g / L of zinc sulfate, 250 g / L of potassium pyrophosphate, 8 g / L of sodium dihydrogen phosphate, 22 g / L of potassium citrate, 22 g / L of potassium sodium tartrate, 0.04 g / L of saccharin, 4 g / L of titanium dioxide, and 18 mL / L of titanium dioxide sol;

[0085] The preparation of titanium dioxide sol includes the following steps: Mix 3.1 g of diethanolamine and 35 mL of ethanol and stir for 30 min, then add 8.68 mL of tetrabutyl titanate, and then add a mixture of 4.5 mL of ethanol and 0.45 mL of distilled water, and stir for 2 h to obtain titanium dioxide sol.

[0086] Comparative Example 2

[0087] Taking Example 3 as the control group, the composite titanium dioxide layer was not electroplated, and other processes were normal.

[0088] A preparation method of a high-strength stainless steel flux-cored wire includes the following steps:

[0089] S1: Prepare the flux powder and set it aside after drying;

[0090] In terms of mass percentage, the composition of the flux powder is: 8% nickel, 28% chromium, 3.5% molybdenum, 2.8% tungsten, 0.2% nitrogen, 1% manganese, 0.11% silicon, and the balance is iron; the working conditions for drying are: temperature 150 °C, heat preservation time 4 h, and furnace cooling;

[0091] S2: Fill the flux powder into the steel strip, and after drawing, obtain the flux-cored wire base material;

[0092] In terms of mass percentage, the composition of the steel strip is: chromium 18%, silicon 0.15%, manganese 0.13%, nickel 49%, carbon 0.02%, molybdenum 3.2%, aluminum 0.6%, titanium 1.01%, boron 0.002%, niobium 5.2%, and the balance is iron;

[0093] The working conditions for drawing are: the feeding speed of the steel strip is 0.3 m / s, the number of drawing passes is 8, the powder filling rate is 26%, and the diameter of the flux-cored wire base material is 2 mm;

[0094] S3: Electroplate a nickel pre-plating layer on the surface of the flux-cored wire base material;

[0095] The working conditions for the nickel pre-plating layer are: the electroplating temperature is 55 °C, the current density is 0.2 A / cm 2 , the electroplating time is 15 min, and the rotation speed of the stirrer is 500 r / min; The composition of the nickel plating solution used for the nickel pre-plating layer is: using deionized water as the solvent, in which nickel sulfate is 240 g / L, nickel chloride is 36 g / L, and boric acid is 32 g / L;

[0096] S4: Perform femtosecond laser processing on the surface of the nickel pre-plating layer; The working conditions for the laser processing are: the laser pulse width is 100 fs, the central wavelength is 800 nm, the repetition frequency is 1 kHz, the laser scanning line spacing is 20 μm, and the laser scanning speed is 200 mm / s, to obtain a high-strength stainless steel flux-cored wire.

[0097] Comparative Example 3

[0098] Taking Example 3 as the control group, femtosecond laser processing was not carried out, and other processes were normal.

[0099] A method for preparing a high-strength stainless steel flux-cored wire, comprising the following steps:

[0100] S1: Prepare flux powder and set it aside after drying;

[0101] In terms of mass percentage, the composition of the flux powder is: nickel 8%, chromium 28%, molybdenum 3.5%, tungsten 2.8%, nitrogen 0.2%, manganese 1%, silicon 0.11%, and the balance is iron; The working conditions for drying are: temperature 150 °C, heat preservation time 4 h, and furnace cooling;

[0102] S2: Fill the flux powder into the steel strip, and after drawing, obtain a flux-cored wire base material;

[0103] In terms of mass percentage, the composition of the steel strip is: chromium 18%, silicon 0.15%, manganese 0.13%, nickel 49%, carbon 0.02%, molybdenum 3.2%, aluminum 0.6%, titanium 1.01%, boron 0.002%, niobium 5.2%, and the balance is iron;

[0104] The working conditions for drawing are as follows: the feeding speed of the steel strip is 0.3 m / s, the number of drawing passes is 8, the powder filling rate is 26%, and the diameter of the flux-cored wire base material is 2 mm;

[0105] S3: Electroplate a nickel pre-coating on the surface of the flux-cored wire base material;

[0106] The working conditions for the nickel pre-coating are as follows: the electroplating temperature is 55 °C, the current density is 0.2 A / cm 2 , the electroplating time is 15 min, and the rotational speed of the stirrer is 500 r / min; The composition of the nickel plating solution used for the nickel pre-coating is: using deionized water as the solvent, including nickel sulfate 240 g / L, nickel chloride 36 g / L, and boric acid 32 g / L;

[0107] S4: Electroplate a composite titanium dioxide layer on the surface to obtain a high-strength stainless steel flux-cored wire;

[0108] The working conditions for electroplating the composite titanium dioxide layer are as follows: the temperature is controlled at 35 °C, the stirring speed is 300 r / min, the electroplating time is 15 min, and the current density is 0.2 A / cm 2 ; The composition of the plating solution used for electroplating the composite titanium dioxide layer is: using deionized water as the solvent, including copper sulfate 30 g / L, stannous chloride 3 g / L, zinc sulfate 8 g / L, potassium pyrophosphate 250 g / L, sodium dihydrogen phosphate 8 g / L, potassium citrate 22 g / L, sodium potassium tartrate 22 g / L, saccharin 0.04 g / L, titanium dioxide 4 g / L, and titanium dioxide sol 18 mL / L;

[0109] The preparation of the titanium dioxide sol includes the following steps: Mix 3.1 g of diethanolamine and 35 mL of ethanol and stir for 30 min, then add 8.68 mL of tetrabutyl titanate, and then add a mixture of 4.5 mL of ethanol and 0.45 mL of distilled water, and stir for 2 h to obtain the titanium dioxide sol.

[0110] Comparative Example 4

[0111] Taking Example 3 as the control group, no titanium dioxide sol was added, and other processes were normal.

[0112] A preparation method of a high-strength stainless steel flux-cored wire, including the following steps:

[0113] S1: Prepare the flux powder and set it aside after drying;

[0114] In terms of mass percentage, the composition of the flux powder is: nickel 8%, chromium 28%, molybdenum 3.5%, tungsten 2.8%, nitrogen 0.2%, manganese 1%, silicon 0.11%, and the balance is iron; The working conditions for drying are: temperature 150 °C, heat preservation time 4 h, and furnace cooling;

[0115] S2: Fill the flux-cored powder into the steel strip. After drawing, obtain the flux-cored wire base material.

[0116] By mass percentage, the composition of the steel strip is: chromium 18%, silicon 0.15%, manganese 0.13%, nickel 49%, carbon 0.02%, molybdenum 3.2%, aluminum 0.6%, titanium 1.01%, boron 0.002%, niobium 5.2%, and the balance is iron.

[0117] The working conditions of drawing are: the feeding speed of the steel strip is 0.3 m / s, the number of drawing passes is 8, the powder filling rate is 26%, and the diameter of the flux-cored wire base material is 2 mm.

[0118] S3: Electroplate a nickel pre-plating layer on the surface of the flux-cored wire base material.

[0119] The working conditions of the nickel pre-plating layer are: the electroplating temperature is 55 °C, the current density is 0.2 A / cm 2 , the electroplating time is 15 min, and the rotational speed of the stirrer is 500 r / min; the composition of the nickel plating solution used for the nickel pre-plating layer is: using deionized water as the solvent, in which nickel sulfate is 240 g / L, nickel chloride is 36 g / L, and boric acid is 32 g / L.

[0120] S4: Perform femtosecond laser processing on the surface of the nickel pre-plating layer.

[0121] The working conditions of the laser processing are: the laser pulse width is 100 fs, the central wavelength is 800 nm, the repetition frequency is 1 kHz, the laser scanning line spacing is 20 μm, and the laser scanning speed is 200 mm / s.

[0122] S5: Electroplate a composite titanium dioxide layer on the surface after laser treatment to obtain a high-strength stainless steel flux-cored wire.

[0123] The working conditions of electroplating the composite titanium dioxide layer are: the temperature is controlled at 35 °C, the stirring speed is 300 r / min, the electroplating time is 15 min, and the current density is 0.2 A / cm 2 ; the composition of the plating solution used for electroplating the composite titanium dioxide layer is: using deionized water as the solvent, in which copper sulfate is 30 g / L, stannous chloride is 3 g / L, zinc sulfate is 8 g / L, potassium pyrophosphate is 250 g / L, sodium dihydrogen phosphate is 8 g / L, potassium citrate is 22 g / L, sodium potassium tartrate is 22 g / L, saccharin is 0.04 g / L, and titanium dioxide is 4 g / L.

[0124] Sources of the raw materials used:

[0125] Nickel sulfate, nickel chloride, boric acid, copper sulfate, stannous chloride, zinc sulfate, potassium pyrophosphate, sodium dihydrogen phosphate, potassium citrate, sodium potassium tartrate, saccharin, diethanolamine, ethanol, tetrabutyl titanate, analytical pure: reagents from the National Pharmaceutical Group; titanium dioxide 13463-67-7: Shanghai Xianxin New Materials Technology Co., Ltd.

[0126] Performance test:

[0127] Refer to GB / T 17853-2018 to test the stainless steel flux-cored wires prepared in Examples 1-3 and Comparative Examples 1-4; the contact angle is measured with a contact angle measuring instrument; the obtained results are shown in Table 1;

[0128]

[0129]

[0130] Table 1

[0131] The present invention provides a preparation method of a high-strength stainless steel flux-cored wire. By defining the composition of the flux core and the steel strip of the stainless steel flux-cored wire, and performing surface treatment on the prepared stainless steel flux-cored wire, a stainless steel flux-cored wire with a micro-nano structure on the surface, dust-proof and easy to clean, is obtained. While improving the strength of the flux-cored wire, the surface dust removal problem is improved, and the cleanliness of the weld structure is improved, thereby making it densified.

[0132] Comparing Example 3 with Comparative Example 1, it can be seen that in order to improve the rust resistance, wear resistance and dust removal and easy cleaning properties of the stainless steel flux-cored wire, surface plating treatment is carried out on the steel flux-cored wire, and the nickel pre-plating layer enhances the bonding force between the composite titanium dioxide layer and the stainless steel flux-cored wire;

[0133] Comparing Example 3 with Comparative Example 2, it can be seen that by using the nano-composite electroplating technology, a titanium dioxide-reinforced Cu-Sn-Zn nano-composite coating is prepared by electroplating. The combination of tin and zinc can make the coating have good corrosion resistance and excellent weldability;

[0134] Comparing Example 3 with Comparative Example 3, it can be seen that by using the femtosecond laser processing technology, a micro-nano structure surface is prepared, thereby greatly improving the self-cleaning property of the stainless steel flux-cored wire surface, and thus improving the welding performance;

[0135] Comparing Example 3 with Comparative Example 4, it can be seen that the titanium dioxide sol helps to improve the surface hydrophobicity.

[0136] The above are only the embodiments of the present invention, and do not limit the patent scope of the present invention accordingly. All equivalent structural transformations made using the description of the present invention under the inventive concept of the present invention, or direct / indirect applications in other related technical fields are included in the patent protection scope of the present invention.

Claims

1. A preparation method of a high-strength stainless steel flux-cored wire, characterized in that, It includes the following steps: S1: Prepare the flux cored powder and keep it for use after drying; S2: Fill the flux cored powder into the steel strip, and after drawing, obtain the flux cored wire base material; S3: Electroplate a nickel pre - coating on the surface of the flux cored wire base material; S4: Conduct femtosecond laser processing on the surface of the nickel pre - coating; S5: Electroplate a composite titanium dioxide layer on the laser - treated surface to obtain a high - strength stainless steel flux cored wire; The working conditions for electroplating the composite titanium dioxide layer are as follows: the temperature is controlled at 30 - 35 °C, the stirring speed is 300 r / min, the electroplating time is 15 min, and the current density is 0.2 A / cm 2 ; The composition of the plating solution used for electroplating the composite titanium dioxide layer is: using deionized water as the solvent, including 30 g / L of copper sulfate, 3 g / L of stannous chloride, 8 g / L of zinc sulfate, 250 g / L of potassium pyrophosphate, 8 g / L of sodium dihydrogen phosphate, 22 g / L of potassium citrate, 22 g / L of sodium potassium tartrate, 0.04 g / L of saccharin, 2 - 4 g / L of titanium dioxide, and 10 - 18 mL / L of titanium dioxide sol.

2. The preparation method of a high-strength stainless steel flux-cored wire according to claim 1, characterized in that, The drying working conditions are: temperature 150°C, heat preservation time 4h, cooling with the furnace; 3. The preparation method of a high-strength stainless steel flux-cored wire according to claim 1, characterized in that, The drawing working conditions are: the feeding speed of the steel strip is 0.3m / s, the number of drawing times is 7 - 8 times, the powder filling rate is 24 - 26%, and the diameter of the flux cored wire base material is 1 - 2mm; 4. The preparation method of a high-strength stainless steel flux-cored wire according to claim 1, characterized in that, By mass percentage, the composition of the flux cored powder is: nickel 7 - 8%, chromium 27 - 28%, molybdenum 3.4 - 3.5%, tungsten 2.1% - 2.8%, nitrogen 0.14 - 0.2%, manganese 0.8 - 1%, silicon 0.9 - 0.11%, and the balance is iron; 5. The preparation method of a high-strength stainless steel flux-cored wire according to claim 1, characterized in that, By mass percentage, the composition of the steel strip is: chromium 18%, silicon 0.15%, manganese 0.13%, nickel 49%, carbon 0.02%, molybdenum 3.2%, aluminum 0.6%, titanium 1.01%, boron 0.002%, niobium 5.2%, and the balance is iron; 6. The preparation method of a high-strength stainless steel flux-cored wire according to claim 1, wherein, The working conditions of the nickel pre - plating layer are as follows: the electroplating temperature is 55 °C, the current density is 0.2 A / cm 2 , the electroplating time is 15 min, and the rotational speed of the stirrer is 500 r / min.

7. The preparation method of a high-strength stainless steel flux-cored wire according to claim 1, characterized in that The composition of the nickel plating solution used for the nickel pre - coating is: using deionized water as the solvent, where nickel sulfate is 240g / L, nickel chloride is 36g / L, and boric acid is 32g / L; 8. The preparation method of a high-strength stainless steel flux-cored wire according to claim 1, characterized in that, The working conditions for laser processing are: laser pulse width is 100fs, central wavelength is 800nm, repetition frequency is 1kHz, laser scanning line spacing is 20µm, and laser scanning speed is 200mm / s; 9. The preparation method of a high-strength stainless steel flux-cored wire according to claim 1, characterized in that The preparation of the titanium dioxide sol includes the following steps: Mix diethanolamine and ethanol and stir for 30min, then add tetrabutyl titanate, and add the mixed solution of ethanol and distilled water, and stir for 1 - 2h to obtain the titanium dioxide sol.

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