CN109023356B - Research on Q235 steel argon arc cladding FeCoCrMoCBY alloy coating - Google Patents
Research on Q235 steel argon arc cladding FeCoCrMoCBY alloy coating Download PDFInfo
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Abstract
The invention relates to a research on Q235 steel argon arc cladding FeCoCrMoCBY alloy coating. Using argon tungsten-arc welding cladding technology to clad alloy powder with different proportions on the surface of Q235 to obtain Fe48‑xCoxCr15Mo14C15B6Y2(x ═ 0,7,9) alloy coating. The influence of the process parameters of the alloy powder, such as ball milling time, coating thickness, drying and heat preservation time, welding current, welding voltage, welding speed and the like, on the coating performance is researched. And (3) researching the microstructure, phase, Vickers hardness and corrosion resistance of the iron-based alloy coating by using a metallographic microscope, an X-ray diffractometer, a Vickers hardness tester and an electrochemical workstation.
Description
Technical Field
The invention relates to the field of amorphous alloy coatings, in particular to research on Q235 steel argon arc cladding FeCoCrMoCBY alloy coatings.
Background
The modernization construction of the twenty-first century is the convergence of informatization and industrialization, and various industrial products are also applied to various complex special environments, including one or more conditions of high temperature, low temperature, high pressure, strong corrosivity, high speed and the like, but steel which is a raw material of most products is likely to suffer from abrasion, breakage, deformation and surface damage such as impact, abrasion and the like in the working environment, so that the application range of the steel material is limited, the service life of the product is shortened, the application field is reduced, and safety accidents and economic losses are easily generated in the using process of the product. Q235 steel is used as an industrial raw material with wide application, is applied to the fields of construction industry, shipbuilding industry, manufacturing industry and the like due to the characteristics of low price, excellent performance and the like and large using amount, but the use range of the Q235 steel is limited due to poor corrosion resistance and low hardness of the surface of the Q235 steel.
The surface cladding technology is a novel technology which is formed and developed rapidly in recent years, and can prepare a composite coating with wear resistance, corrosion resistance and high hardness on the surface of a workpiece on the premise of using lower cost, so that the overall performance of a product is optimized, the reliability is enhanced, the service time is prolonged, the cost of an enterprise is saved, and the economic value is increased. The metallurgical reaction of the argon tungsten-arc cladding is relatively simple in practical application, the operability is strong, and the coating in an ideal state can be obtained. And the electric arc at the tungsten electrode is extremely stable in the argon arc cladding process, and can be easily ignited and combusted under a small current, so that the method is suitable for cladding the sheet material. The argon arc cladding alloy powder coating is used on the Q235 steel matrix, so that the corrosion resistance, the hardness and the like of the surface are improved, and the overall performance of the alloy is greatly improved.
The surface cladding technology is to heat an externally added alloy to melt the alloy and a matrix to form a metallurgical alloy, so as to prepare a surface coating layer with various excellent properties. An alloy layer is deposited on the surface of the existing matrix, so that the original mechanical properties of the matrix can be maintained, the surface wear resistance, corrosion resistance, impact resistance, hardness and the like can be greatly enhanced, the service life of the product is well prolonged, the safety risk is reduced, and the economic performance is better. The existing surface cladding technology comprises induction surface cladding, laser surface cladding, plasma cladding, thermal spraying technology, surfacing surface cladding, tungsten electrode argon arc cladding and the like.
The tungsten electrode argon arc cladding is different from other technologies in that heat is concentrated under argon arc gas at a tungsten electrode, energy density is between free electric arc and compression arc, and operation flexibility is high. The argon arc cladding coating preparation process has no oxidation burning loss phenomenon in heating and cooling. Argon arc welding has many advantages:
(1) under the protection of argon, the melting pool has less burning loss of alloy elements, so that the method is a mainstream cladding method, and the technical means can not only modify the surface, enhance various excellent properties, but also obtain ideal fusion depth;
(2) in the cladding process, the electrode, the arc area and the molten metal are simultaneously under the protection of inert gas-argon, so that the electrode, the arc area and the molten metal can be in a state of ideally isolating air, and adverse reactions such as oxidation and the like of the metal in the melting process are reduced;
(3) compared with other cladding technologies, the tungsten electrode argon arc welding equipment has lower price, simpler and more convenient operation and easier popularization and popularization;
(4) the argon arc cladding can realize a series of cladding with complicated shapes, large parts, and limited conditions of field working and the like which are difficult to realize such as laser cladding.
There are three common techniques for argon tungsten-arc cladding, namely, a pre-coated alloy powder argon tungsten-arc direct-fusion method, an alloy welding wire argon tungsten-arc direct-fusion method, and an alloy element indirect-fusion method.
The tungsten electrode cladding material comprises two types, one type is a base material, and the other type is a cladding layer material pre-coated on the base.
The base material is selected from metal materials which are widely used in the current industrial production, so that the economic value can be improved and the production cost can be reduced by adding the cladding layer under the condition of not causing great influence on the existing production process. Alternative substrate materials include carbon steel, cast iron, aluminum alloys, manganese alloys, chromium alloys, magnesium alloys, and the like. The Q235 steel is widely applied to buildings and engineering structures, is used for manufacturing mechanical parts such as steel bar factory building frames, bridges, vehicles, ships and the like, and has high use value and research value. However, Q235 steel has poor properties such as corrosion resistance and surface hardness, is often used for manufacturing mechanical parts with low performance requirements, is not favorable for Q235 to be used in certain ranges, and limits the application field of the Q235 steel. Most of the existing surface cladding technology uses argon arc as a heat source to heat alloy powder or non-alloy powder such as ceramic powder and the like, so that the alloy powder or the non-alloy powder and the surface layer of a matrix are rapidly heated and melted and are mutually fused to obtain an alloy cladding layer which contains different components and has greatly improved performance, thereby obviously improving the corrosion resistance, the wear resistance, the heat resistance, the oxidation resistance, the hardness increasing and the like of the surface of the matrix material. The selection of the cladding alloy powder also becomes a critical step. The alloy powder can form various compounds after high-temperature cladding, the compounds can increase the wear resistance and hardness of the surface of the alloy, the melting point of the alloy is greatly reduced compared with that of the original matrix metal iron, and the cladding difficulty is also reduced in the argon arc welding process. The self-fluxing alloy is an alloy with excellent degassing, deoxidizing and wetting performances and slagging performance, and has the functions of self-deoxidizing and slagging, namely self-fluxing.
Self-fluxing alloys are further subdivided by the differences in their main constituents: nickel-base self-fluxing alloy, cobalt-base self-fluxing alloy and iron-base self-fluxing alloy. The alloy can form a film on the surface of a cladding layer to prevent alloy elements from being oxidized, and boron can also reduce the melting point of the alloy, increase the infiltration effect of the alloy and generate favorable influence on the fluidity and the surface tension of the alloy. The iron-based self-fluxing alloy is widely used, and the high-carbon and high-chromium self-fluxing alloy contains high proportion of carbon and chromium in the components, so that the obtained cladding layer structure contains more borides and carbides through eutectic pig iron, and has high hardness, good wear resistance and good corrosion resistance.
Disclosure of Invention
Aiming at the problems in the prior art, the simple cobalt, simple chromium, simple molybdenum, simple carbon, pure boron and simple yttrium are added into the iron-based powder in a proper proportion to prepare different kinds of alloy powder as the cladding material. By analyzing the properties of cladding materials with different proportions in the Q235 steel surface coating, the performance and the organizational structure of the coating are researched, the reason for improving the surface performance is improved, and the application of the argon arc cladding surface modification technology in actual production life is popularized.
In order to achieve the purpose, the invention adopts the technical scheme that:
a method for cladding an iron-based alloy corrosion-resistant coating on the surface of Q235 steel by argon tungsten-arc welding comprises the following steps:
uniformly mixing seven alloy powders of Fe, Co, Cr, Mo, C, B and Y, and performing ball milling to obtain mixed powder;
adding water glass into the mixed powder, uniformly mixing, coating on the surface of a Q235 matrix, drying, and carrying out cladding treatment by adopting argon tungsten-arc welding to obtain the amorphous alloy coating.
The method selects iron, cobalt, chromium, molybdenum, carbon, boron and yttrium elements from powder elements of the cladding layer. The reason for selecting cobalt element, molybdenum element and yttrium element is as follows: the cobalt bonds other metal carbide grains in the alloy structure, so that a new product obtains better toughness, the cobalt has excellent wettability on a hard phase, the sensitivity of the surface to impact is reduced, in addition, the cobalt also plays a certain delay role in intergranular corrosion, and the alloy component is cladded on the surface of a part, so that the service life of the part can be prolonged by 3-7 times. The molybdenum has the main functions of enhancing the corrosion resistance of the alloy in reducing media (such as sulfuric acid, phosphoric acid, organic acid, urea and other environments), and also can enhance the pitting corrosion resistance, crevice corrosion resistance and other capabilities of the alloy, and the elasticity limit and the fire resistance can be improved by adding the molybdenum into the alloy. Yttrium can be used as an additive to steel and non-ferrous alloys to enhance the oxidation resistance and ductility of these metals. In some embodiments, the molar ratio of Fe, Co, Cr, Mo, C, B, Y is 48-x: x: 15:14:15:6:2, wherein x is 0,7, 9.
Although the laser cladding technology is rapidly developed in recent years, the laser cladding technology is mainly applied to the high-end metal part repair market due to higher cost and harsh process conditions. In order to meet the use requirements of the repair market of medium and low-end metal parts, the FeCoCrMoCBY alloy coating is prepared by argon tungsten-arc welding cladding, but the research shows that: because the types of the raw materials in the alloy powder are more, the dispersibility of the raw materials is poor after the raw materials are directly mixed, and the formed alloy coating has poor corrosion resistance due to poor matching of the mixed alloy powder and the argon tungsten-arc welding cladding process. Therefore, the system of the application researches the influence of various mixing processes on the mixing effect of FeCoCrMoCBY alloy powder and the argon tungsten arc welding cladding effect, and after large-scale experiments, the following results are found: the matching degree of FeCoCrMoCBY alloy powder subjected to ball milling treatment by adopting a specific process and the argon tungsten-arc welding cladding process is higher, the generation and the uniform dispersion of a Fe-Cr phase in a matrix can be effectively promoted, and the Fe2B and Fe23(C,B)6The content of the equal hard phase is also higher, so that the prepared FeCoCrMoCBY alloy coating has high corrosion resistance and high hardness.
The research of the application finds that: compared with the general purifiers, B2O3The melting point is very low, the adsorption efficiency to oxide inclusions is higher when FeCoCrMoCBY alloy is melted, and the purity of alloy melt is better.
In some embodiments, the ball milling is performed using a stainless steel ball mill pot and zirconia milling balls, with a ball to feed ratio of 15:1 being selected.
In some examples, the ball mill uses 2 different sized grinding balls with diameters of 10mm and 5mm, respectively, in a 1:8 ratio.
In some embodiments, the ball milling time is 32 hours, the rotating speed is 100 revolutions per minute, the operation mode is that positive and negative rotation are alternately carried out, the rotation is carried out for 30min, and the machine is stopped for 10 min.
In some embodiments, the thickness of the mixed powder coated on the surface of the Q235 substrate is 1-2 mm.
In some embodiments, the drying comprises the specific steps of: drying for 2 hours and 1 hour at 80-120 ℃ and 120-160 ℃ respectively.
In some embodiments, the current of the argon tungsten-arc welding is 115-120A, the voltage is 13-14V, the argon gas flow rate is selected to be 8-10L/min, the moving speed of the argon tungsten-arc welding is 0.4-0.6 m/min, and the arc length is 2-4 mm.
The present application provides a corrosion resistant coating prepared by any of the above-described methods.
The application also provides the application of the Q235 steel loaded with the corrosion-resistant coating in manufacturing of mould parts, reinforcing steel bars, factory building frames, high-voltage transmission towers, bridges, vehicles, boilers, containers or ships, and is characterized in that the mould parts comprise: a punch and a die handle.
Compared with the prior art, the invention has the beneficial effects that:
according to the method, through a tungsten electrode argon arc cladding technology, alloy powder with different components is prepared and coated on the surface of Q235 steel serving as a matrix, and cladding is carried out at high temperature through argon arc welding to obtain a surface cladding layer superior to the matrix. The following main conclusions can be obtained by observing and shooting the metallographic microstructure of the cladding layer on the surface, analyzing an XRD phase, testing the surface hardness and the surface corrosion resistance and analyzing the performance of the cladding layer surface, and integrating various factors and influences:
1) the surface cladding layer with good appearance and firm joint can be obtained by adopting the argon tungsten-arc welding cladding technology.
2) Phase analysis shows that the height of the diffraction peak of the cladding layer with X-7 is obviously lower than that of other cladding layers, so that the diffraction peak has less crystal components and wider half-height width of the diffraction peak, so that the size of crystal grains is smaller, and the coating with X-7 contains the hard phase Fe which is not contained in the coating with other components23(C,B)6And the highest diffraction peak of Fe-Cr phase is obtained when X is 9.
3) The hardness of the alloy is proved to contain Fe by Vickers hardness test48-xCoxCr15Mo14C15B6Y2The surface hardness of the (X-0, 7,9) cladding layer is greatly improved compared with that of the substrate, wherein the hardness of X-7 is as high as 689.85HV0.1 on average and is 4.4 times of that of the substrate, and the newly generated hard phase Fe in the coating layer2B phase, Fe23(C,B)6The hardness of the surface of the cladding layer can be improved.
4) Through electrochemical corrosion experiments, the corrosion current density of the cladding layer is obviously lower than that of the substrate, and the corrosion current density of the coating with X ═ 9 is as low as 3.75455 multiplied by 10 on average-6A/cm2Current density 9.8757X 10 far below that of the substrate-5A/cm2The content of the newly generated Fe-Cr phase of the coating is higher, and the corrosion resistance is also better.
Drawings
The accompanying drawings, which are incorporated in and constitute a part of this application, illustrate embodiments of the application and, together with the description, serve to explain the application and are not intended to limit the application.
FIG. 1 impact of power connection on cladding coatings;
FIG. 2 coating B2O3The effect on coating properties;
FIG. 3 shows XRD analysis results of the same proportion of cladding coating. (a) A substrate; (b) x is 0 without B2O3(ii) a (3) X is 7, and B is added2O3(ii) a (4) X is 9, and B is added2O3。
FIG. 4 is a gold phase diagram of the cladding coating. (a) A substrate; (b) x is 0 without B2O3(ii) a (c) X is 7, and B is added2O3(ii) a (d) X is 9, and B is added2O3。
FIG. 5 base, x ═ 0 without B2O3X is 0 plus B2O3X is 7 without B2O3X is 7 plus B2O3X is 9 without B2O3X is 9 plus B2O3Polarization curve of the sample.
Detailed Description
It should be noted that the following detailed description is exemplary and is intended to provide further explanation of the disclosure. Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs.
It is noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of example embodiments according to the present application. As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, and it should be understood that when the terms "comprises" and/or "comprising" are used in this specification, they specify the presence of stated features, steps, operations, devices, components, and/or combinations thereof, unless the context clearly indicates otherwise.
As described in the background art, the problem of poor corrosion resistance of the amorphous alloy coating of Q235 steel in the prior art exists, the application provides a method for cladding the corrosion-resistant coating of the iron-based alloy on the surface of the Q235 steel by argon tungsten-arc welding, and the invention is further described with reference to specific embodiments.
Example 1:
(I) test materials
1. Base material
Rolled Q235 steel is selected as a base material, and due to the standing time and the standing environment, rust, dirt, grease and the like exist on the surface of the steel, and all the influencing factors can generate adverse influence on the following surface cladding process, so that the surface of the base body is pretreated before cladding of a coating. The rust stain on the surface of the Q235 steel is removed by using an angle grinder, the surface of the Q235 steel is polished to be bright, then absorbent cotton is used for dipping absolute ethyl alcohol to erase and clean the surface, then an air blower is used for drying the ethyl alcohol, and the dried surface is placed in a drying box for later use.
2. Preparation of cladding coating
(1) Alloy coating material selection
Selecting seven alloys of Fe, Co, Cr, Mo, C, B and Y as prepared materials, wherein the molar ratio of each element is 48-x: x: 15:14:15:6:2, i.e. Fe48-xCoxCr15Mo14C15B6Y2(x is 0,7, 9). Wherein the total mass of the powder with different components is 20g, two parts of the powder with different components are prepared respectively, wherein one part is not treated, and boron trioxide with the mass of 10 percent of the original powder is added into the other part; marking each powder and labeling.
(2) Treatment of alloy coating material powder
And (3) uniformly grinding the prepared mixed powder in a ball mill. A stainless steel ball milling tank and zirconia grinding balls are adopted, and the ball-to-material ratio is 15: 1; 2 types of grinding balls with different specifications are used, the diameters are respectively 10mm and 5mm, the number ratio is 1:8, the total volume of the zirconium balls and the powder is preferably 1/3 of the ball milling tank, the ball milling time is 32 hours, the rotating speed is 100 revolutions per minute, the operation mode is that positive and negative rotation are alternately carried out, the rotation is carried out for 30min, and the machine is stopped for 10 min.
(3) Coating of powders
And (2) taking water glass as a binder, uniformly mixing the prepared powder with the water glass, coating the powder on the surface layer of a Q235 matrix, reserving the thickness of 1-2 mm, and then putting the sample in a dryer to be dried for 2 hours and 1 hour at 80-120 ℃ and 120-160 ℃ respectively.
(4) Preparation of amorphous alloy coating by argon arc cladding
The argon arc cladding preparation process parameters comprise: the polarity of welding current is pre-tested before cladding the coating, alternating current or direct current is selected to be adopted by comparing the characteristics of alternating current and direct current, the current is 115-120A, the voltage is 13-14V, the argon gas flow rate is selected to be 8-10L/min, the moving speed of an argon arc welding tungsten electrode is 0.4-0.6 m/min, the arc length is 2-4 mm, and the parameter characteristics are selected according to actual experience: the current is 120A, the voltage is 13V, the argon flow is 10L/min, the moving speed of the argon arc welding tungsten electrode is 0.5 m/min, and the arc length is 3.5 mm.
3. Experimental equipment
Various devices are used in the experimental and analytical processes, and the main devices and their models to be used are listed below:
electronic scales
Angle grinder
Stainless steel pot for zirconia balls of ball mill
Drying machines
Argon tungsten-arc welding equipment
Trolley for controlling moving speed of tungsten electrode
Shanghai Huachi 660e electrochemical workstation
MHV-100Z type digital microscopic Vickers hardness tester
AxioCam ERc 5s microscope camera
XQ-1 metallographic specimen inlaying machine
Rigaku Ultima IV X-ray diffractometer
Microstructure and phase analysis of (II) coatings
1. Microstructural analysis
The generation and development of the metallography provide another idea for researching the materials science, and the extended research and analysis of the metallography also have revolutionary breakthrough, and the research and analysis of the metallography mainly comprises an emerging subject which is analyzed and characterized by depending on microscopic conditions such as a metallographic microscope, a stereomicroscope and the like, such as a microstructure, a low-magnification tissue structure, a fracture microstructure and the like of a research object, wherein the emerging subject comprises the imaging of the materials under the microscope and the qualitative and quantitative characterization of the materials, and the emerging subject also has sample preparation, early pretreatment, sampling means and the like before observation. The most representative of the characteristics of the metal material includes phase and phase components, grains or subgrains, non-metallic inclusions, and the distribution, size, morphology, orientation, number and arrangement state of the spatial positions of defects contained in certain crystals, such as various types of dislocations, and the like.
Before observing and shooting the microstructure by using a metallographic microscope, firstly, a sample is processed, and the processing process comprises the following steps:
(1) the substrate with the cladding layer was cut into test pieces of 10mm × 10mm × 9mm in uniform size by a cutter.
(2) Putting the sample into an inlaying machine, pouring moderate thermosetting resin inlaying powder, screwing a hand wheel, setting the heating temperature to be 150 ℃, keeping the temperature for 8 minutes, and taking out the sample after cooling for 20 minutes.
(3) And grinding and polishing the embedded sample. The metallographic abrasive paper of 400 meshes, 600 meshes, 800 meshes, 1000 meshes, 1500 meshes and 2000 meshes is respectively placed on a polishing and grinding machine, the water flow is adjusted, the polishing and grinding machine is started, the sample is held by hands with uniform force, the sample cannot be pressed in one direction, and the sample is continuously polished after being rotated by about 30 degrees after being polished for 15 seconds, so that the sample is uniformly stressed. Before each time of replacing the abrasive paper, whether the abraded surface has scratches or not and whether the brightness is consistent or not are observed, so that the detected surface is on the same horizontal plane.
(4) When the surfaces to be detected meet the required requirements, the surfaces are corroded, firstly, a 6% nitric acid solution is prepared, and 3ml nitric acid and 47ml absolute ethyl alcohol are used for modulation. Dipping a 6% nitric acid solution on the surface to be tested by using a cotton swab, spraying an ethanol solution for cleaning after waiting for 10 seconds, and then drying the surface to be tested by using a blower.
And placing the processed metallographic specimen on a metallographic microscope, gradually increasing the magnification by 50 times, 100 times, 200 times and 500 times according to the principle of increasing from small to large, observing and debugging the surface of the specimen, finding the position with the clearest imaging, photographing the position with the better coating effect and preparing a scale.
XRD phase analysis
The X-ray diffractometer utilizes the diffraction principle of light, and due to the particularity of the structure of a crystal material, under the condition that the angles of a crystal to be detected and incident rays are different, crystal faces meeting a Bragg diffraction formula can show that diffraction peaks representing different diffraction intensities appear on a diffraction pattern. The crystal types contained in the material can be accurately measured through an X-ray diffractometer, qualitative and quantitative analysis is facilitated, and relatively accurate phase research is realized.
The substrate with the cladding layer was cut into samples of 10mm × 10mm × 9mm size by a cutter, placed on a cover plate for holding the samples, and mounted on a Rigaku Ultima IV X-ray diffractometer for phase analysis.
(III) coating performance detection method
1. Vickers microhardness test
The cutting machine cuts the substrate with the cladding layer into samples with the size of 10mm multiplied by 9mm, the samples are placed on a model MHV-100Z type digital display micro Vickers hardness tester, the adjusting test force is 0.9807N (100gf), the adjusting force load-holding time is 10 seconds, and each sample is replaced by at least 3 test points for carrying out value taking for a plurality of times so as to have stronger reliability.
2. Electrochemical corrosion test
The application analyzes and compares the corrosion resistance of the coating layer on the surface of the substrate by using an electrochemical workstation. An electrochemical workstation of chi660e model of Shanghai Chenghua is adopted, a calomel electrode is taken as a reference electrode, a platinum electrode is taken as an auxiliary electrode, and the working electrode is connected with a sample to be detected. Because only the surface to be measured is a coating layer, other five non-coating layers need to be subjected to coating pretreatment, and the method mainly comprises the following steps:
(1) cutting the substrate with the cladding layer into corrosion samples of 10mm multiplied by 9mm by a cutting machine, manually polishing the surfaces of the samples by using 1000-mesh abrasive paper, removing slag and an oxide layer on the surfaces, and taking care not to cause the coating to be abraded due to too much strength;
(2) placing the sample in an ethanol solution, carrying out ultrasonic cleaning, taking out the sample by using tweezers, and blowing the sample to dry by using a blower;
(3) punching a small hole on the back of the cladding layer by using a drilling machine, putting one end of a copper wire into the small hole, and welding soldering tin and the copper wire by using an electric soldering iron to fix a sample;
(4) and (3) coating and sealing all the other five surfaces except the surface containing the coating layer by using a hot melting gun, and ensuring that only the surface to be detected is exposed outside.
The salt bridge in the electrochemical corrosion experiment is a lujin capillary, so that a supersaturated potassium chloride solution is prepared firstly: 16g of potassium chloride powder is weighed, 50g of distilled water is taken out by using a measuring cylinder, the two are poured into a clean beaker, the dissolution is accelerated by using a glass rod for stirring, and a small amount of undissolved potassium chloride is seen at the bottom of the beaker.
Preparing an electrolytic solution in which the working electrode is positioned in a corrosion experiment, namely a sodium chloride solution with the mass fraction of 6.76%. 14.5g of sodium chloride powder was weighed into a clean beaker, and 200g of distilled water was weighed into a beaker using a measuring cylinder and stirred with a glass rod until the sodium chloride was completely dissolved.
After the preparation work is finished, performing an electrochemical corrosion experiment, comprising the following steps:
(1) taking out the luggin capillary, sucking out saturated potassium chloride solution by using a rubber head dropper, adding the saturated potassium chloride solution into the luggin capillary, and inserting a calomel reference electrode into the luggin capillary;
(2) taking out the reaction vessel of the electrochemical experiment, pouring 6.76% sodium chloride solution into the reaction vessel, inserting the auxiliary electrode (platinum electrode), the working electrode and the reference electrode from the upper part of the vessel, connecting with respective leads by using clips according to requirements, opening the electrochemical workstation, opening software on a computer, testing open-circuit voltage at first, and then measuring a Tafel curve by using the open-circuit voltage.
(IV) characterization of the cladding layer
According to the principle of electric arc welding, the argon arc welding power supply method has important influence on welding performance, when direct current is in direct current, the base metal is connected with an anode, and the base metal is more molten during cladding; when the alternating current is supplied, the base material has the cathode cleaning function in the cathode connection stage. Fig. 1 shows the effect of power connection on cladding coating. As can be seen from fig. 1, the surface layer formed by direct current direct welding cladding is deep and narrow, the width-depth ratio is increased by alternating current cladding, the represented cladding layer is shallow and wide, the cladding layer with a larger area can be obtained, samples can be prepared in the following steps conveniently, and the surface of the coating layer is bright due to the cathode cleaning effect, so that the alternating current cladding technology is adopted.
Coating material for useThe material purity is low, and impurities are inevitable in the coating. B is2O3The fusing agent has low melting point, can protect a molten pool, can adsorb impurities, and has a purifying effect on the coating. It can be seen from the sample where X is 7 that B is not added2O3Has narrower cladding layer width and smaller melting depth, and B is added2O3The cladding layer of the sample is wider, and the cladding efficiency is higher. And due to B2O3The purification effect of the method improves the forming of the cladding layer greatly, forms obvious fish scale grains and improves the cladding effect.
FIG. 3 shows Fe48-xCoxCr15Mo14C15B6Y2XRD of the (x ═ 0,7,9) component cladding layer and the substrate as a control. As can be seen from FIG. 3, the matrix contains only the Fe phase, while X is 0 and B is not added2O3X ═ 7 and B are added2O3X is 9 and B is added2O3The coating layer mainly comprises Fe phase, Fe-Cr phase and Fe2B phase, Cr1.36Fe0.52Phase, Cr phase. And Fe is also contained in the map of X-723(C,B)6And Cr7C3Phase, and its Fe — Cr phase diffraction peak height is much lower than the height of X ═ 0 and X ═ 9, indicating less crystalline content. As can be seen from the comparative graph of X-0, X-7, and X-9, where the width of the half-peak of the diffraction peak of X-7 is significantly wider and the width of the half-peak is inversely proportional to the grain size, indicating that the grain size of X-7 is greater than that of X-0, X-9 is smaller, and the width of the half-peak of X-9 is smaller, indicating that the grain size is maximum, and the width of the half-peak of X-9 is slightly greater than that of X-9.
FIG. 4 is a gold phase diagram of the cladding coating. (a) A substrate; (b) x is 0 without B2O3(ii) a (c) X is 7, and B is added2O3(ii) a (d) X is 9, and B is added2O3. Microstructure taken using a metallographic microscope at 200 x magnification: as can be seen from the gold phase diagrams of the cladding layers in FIGS. 4(b), (c) and (d), there is a clear presence between the insert and the base materialThe layer of the glass is a bright tissue, which is a coating subjected to argon arc cladding. The color of the cladding layer where X ═ 7 in fig. 4(c) is close to that of the substrate, indicating that the corrosion resistance is less different from that of the substrate. Whereas the brightness of the coating in fig. 4(b) and (d) is much brighter than its substrate for X-0 and X-9. The grain structure of the comparative base Q235 steel after being corroded by nitric acid solution is observed, and no obvious crystal structure is observed in the other three cladding layers.
(V) analysis of Properties of cladding layer
1. Hardness analysis of cladding layer
Table 1 shows the results of the vickers hardness test of the cladding layer surface. As can be seen from Table 1, the average Vickers hardness of the cladding layer can be 698.7HV0.1 at the maximum and 246.3HV0.1 at the minimum, while the hardness of the substrate surface can be 157.3HV 0.1. The hardness values are compared to obtain that the hardness of the cladding layer is obviously greater than that of the surface of the substrate which is not coated with the coating, which indicates that the argon arc cladding coating can improve the hardness of the surface of the material.
The key point in creating a high hardness coating is that a reasonable hard phase is formed, and the type and particle size of the hard phase produced also has an effect on the overall hardness, with higher hardness of the hard phase producing greater amounts of hard phase dispersed more uniformly in the matrix and higher overall hardness of the coating. As can be observed from the coating XRD pattern of FIG. 3, Fe is generated on the surface of the cladding layer2The hard phase B and the solid solution strengthening effect of Cr on the matrix are added, and Co has good wettability and good cohesiveness on the hard phase, so that the hardness of the surface of the matrix is improved. And in Fe48-xCoxCr15Mo14C15B6Y2The hardness of the cladding layer is the highest when X is 7, and the hard phase Fe in the cladding layer is also known from XRD pattern analysis2B is more than X0 and X9, and there is much more hard phase Fe than the other two cladding layers23(C,B)6Phase, it is known that Fe is accompanied by2B and Fe23(C,B)6The hardness of the coating can be obviously improved by increasing the content.
TABLE 1 Vickers hardness number (HV0.1) of the coated surface
2. Analysis of Corrosion resistance of cladding layer
The Open Circuit Potential (OCPT), i.e. the electrode potential at a current density of 0, i.e. the potential difference between the working electrode and the reference electrode without load, was first measured. The corrosion probability of the metal can be conveniently measured and judged by comparing the open-circuit potential, but the corrosion rate and the corrosion condition of the metal cannot be known. When an open-circuit potential test is carried out, the obtained open-circuit potential is required to be stable voltage, namely, the fluctuation of one minute is not more than 1mv or the fluctuation of two minutes is not more than 3 mv.
After the open circuit potential is obtained by the method, when measuring Tafel image, a Tafel image in the range of 300mv is added or subtracted on the basis of the potential, the scanning speed is selected to be 5mv/s, and the sensitivity is calibrated to be automatic sensitivity adjustment.
And (4) sequentially testing the samples, and drawing to obtain a Tafel polarization curve.
TABLE 2 electrochemical Corrosion test results
As can be seen from fig. 5 and table 2, the corrosion current density of the sample with argon arc-clad surface is significantly lower than that of the uncoated substrate, and the smaller the corrosion current density, the better the corrosion resistance of the material, so electrochemical corrosion experiments show that the corrosion resistance of the sample with a coating layer is greatly improved compared with the substrate, and the coating with the best corrosion resistance performance is X ═ 9, which is much better than X ═ 7, and the better effect is than X ═ 0.
Generally, the corrosion resistance of the surface of the alloy is greatly influenced by the structure of the alloy, and in the multi-phase alloy, when the phase is present in the form of inclusion in a finer and more dispersed state, the micro-battery is more likely to be formed, resulting in the reduction of the corrosion resistance. In general, when the components are substantially the same, the width of the half-peak of the diffraction peak of the same phase and the size of the crystal grain are constantIn connection with this, when the grain size is large, the half height peak width of the diffraction peak is narrow, and in the XRD pattern with X ═ 7, the half height peak width of the diffraction peak is wider than those of the other two cladding layers, indicating that the grain size is smaller, and the half height peak with X ═ 9 is narrowest, indicating that the grain size is largest, and the Cr concentration at the grain boundary with a large grain size is higher than that near the grain boundary with a small grain size, thereby making the sensitization degree with a large grain size lower. And the most closely related to the corrosion resistance is the Fe-Cr phase, namely the Fe-Cr phase is dispersed in the matrix more uniformly and the content is higher, so that the corrosion rate can be reduced, and the corrosion resistance is improved, wherein the peak height of the Fe-Cr phase is the highest when X is 9, and the diffraction peak height of the Fe-Cr phase is the lowest when X is 7. And Cr is also present in the cladding layer with X ═ 77C3Phase of Cr7C3When the grain boundary is precipitated, the concentration of C and Cr near the grain boundary is reduced, the nearby C and Cr are diffused, and C formed by chromium carbide can be obtained from the inside of the grain, while Cr is mainly obtained from the nearby grain boundary, because the radius of Cr atoms is larger, the diffusion speed is slower, and the Cr is not easy to diffuse to the boundary, the Cr diffusion in the grain is more difficult than along the grain boundary. And the diffusion speed of Cr atoms is higher than that of Fe atoms, so that the Cr content at the grain boundary is reduced, a Cr-poor area is formed, and the intergranular corrosion performance is harmful. Therefore, in the corrosion resistance test, the corrosion current density of X-7 is the largest and the corrosion resistance is the worst, and the current density of X-9 is the lowest and the corrosion resistance is the best.
The above description is only a preferred embodiment of the present application and is not intended to limit the present application, and various modifications and changes may be made by those skilled in the art. Any modification, equivalent replacement, improvement and the like made within the spirit and principle of the present application shall be included in the protection scope of the present application.
Claims (6)
1. A method for cladding an iron-based alloy corrosion-resistant coating on the surface of Q235 steel by argon tungsten-arc welding is characterized by comprising the following steps: uniformly mixing seven alloy powders of Fe, Co, Cr, Mo, C, B and Y, and performing ball milling to obtain mixed powder;
adding water glass into the mixed powder, uniformly mixing, coating the mixture on the surface of a Q235 matrix, drying, and carrying out cladding treatment by adopting argon tungsten-arc welding to obtain an amorphous alloy coating;
the molar ratio of Fe, Co, Cr, Mo, C, B and Y is 48-x: x: 15:14:15:6:2, wherein x is 0,7, 9;
b with the mass fraction of 1-10% is also added into the alloy powder2O3；
The ball milling adopts 2 types of grinding balls with different specifications, the diameters of the grinding balls are respectively 10mm and 5mm, and the number ratio is 1: 8; the ball milling adopts a stainless steel ball milling tank and zirconia grinding balls, and the ball material ratio is 15: 1; the current of the argon tungsten-arc welding is 115-120A, the voltage is 13-14V, the argon gas flow rate is selected to be 8-10L/min, the moving speed of the argon-arc welding tungsten electrode is 0.4-0.6 m/min, and the arc length is 2-4 mm.
2. The method for cladding the iron-based alloy corrosion-resistant coating on the surface of the Q235 steel by argon tungsten-arc welding as claimed in claim 1, wherein the ball milling time is 32 hours, the rotating speed is 100 revolutions per minute, the operation mode is that positive and negative rotation are alternately carried out, the rotation is carried out for 30min, and the machine is stopped for 10 min.
3. The method for cladding the iron-based alloy corrosion-resistant coating on the surface of the Q235 steel by argon tungsten-arc welding as claimed in claim 1, wherein the thickness of the mixed powder coated on the surface of the Q235 matrix is 1-2 mm.
4. The method for cladding the iron-based alloy corrosion-resistant coating on the surface of the Q235 steel by argon tungsten-arc welding according to claim 1, wherein the drying comprises the following specific steps: drying for 2 hours and 1 hour at 80-120 ℃ and 120-160 ℃ respectively.
5. A corrosion resistant coating prepared by the method of any one of claims 1-4.
6. Use of Q235 steel loaded with a corrosion-resistant coating according to claim 5 for the manufacture of a mould part, a steel bar, a factory building frame, an iron tower, a bridge, a vehicle, a boiler, a container or a vessel, wherein the mould part comprises: a punch and a die handle.
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Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
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| CN106245025A (en) * | 2016-08-15 | 2016-12-21 | 常熟理工学院 | A kind of Argon arc cladding high hardness wear-resisting alloy powder |
| CN106378519A (en) * | 2016-11-16 | 2017-02-08 | 武汉理工大学 | Alloy powder material for high heat-resisting strength iron-based cladding layer and cladding layer preparation method |
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Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
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| CN106245025A (en) * | 2016-08-15 | 2016-12-21 | 常熟理工学院 | A kind of Argon arc cladding high hardness wear-resisting alloy powder |
| CN106378519A (en) * | 2016-11-16 | 2017-02-08 | 武汉理工大学 | Alloy powder material for high heat-resisting strength iron-based cladding layer and cladding layer preparation method |
Non-Patent Citations (1)
| Title |
|---|
| "脉冲频率对激光熔覆FeCoCrMoCBY 涂层组织与性能的影响";龚玉兵等;《稀有金属》;20160804;第41卷(第10期);第1117-1124页 * |
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