CN114505615B - Flux-cored wire special for deep sea wet FCAW and preparation method - Google Patents
Flux-cored wire special for deep sea wet FCAW and preparation method Download PDFInfo
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- CN114505615B CN114505615B CN202210184966.XA CN202210184966A CN114505615B CN 114505615 B CN114505615 B CN 114505615B CN 202210184966 A CN202210184966 A CN 202210184966A CN 114505615 B CN114505615 B CN 114505615B
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
- B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
- B23K35/00—Rods, electrodes, materials, or media, for use in soldering, welding, or cutting
- B23K35/02—Rods, electrodes, materials, or media, for use in soldering, welding, or cutting characterised by mechanical features, e.g. shape
- B23K35/0255—Rods, electrodes, materials, or media, for use in soldering, welding, or cutting characterised by mechanical features, e.g. shape for use in welding
- B23K35/0261—Rods, electrodes, wires
- B23K35/0266—Rods, electrodes, wires flux-cored
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
- B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
- B23K35/00—Rods, electrodes, materials, or media, for use in soldering, welding, or cutting
- B23K35/22—Rods, electrodes, materials, or media, for use in soldering, welding, or cutting characterised by the composition or nature of the material
- B23K35/24—Selection of soldering or welding materials proper
- B23K35/30—Selection of soldering or welding materials proper with the principal constituent melting at less than 1550 degrees C
- B23K35/3053—Fe as the principal constituent
- B23K35/308—Fe as the principal constituent with Cr as next major constituent
- B23K35/3086—Fe as the principal constituent with Cr as next major constituent containing Ni or Mn
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
- B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
- B23K35/00—Rods, electrodes, materials, or media, for use in soldering, welding, or cutting
- B23K35/40—Making wire or rods for soldering or welding
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
- B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
- B23K9/00—Arc welding or cutting
- B23K9/0061—Underwater arc welding
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
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Abstract
The invention relates to a flux-cored wire special for deep sea wet FCAW and a preparation method thereof, belonging to the technical field of welding wires and comprising an outer steel belt and an inner flux core, wherein the outer steel belt is made of stainless steel and comprises the following materials: carbon, chromium, nickel, titanium, niobium, molybdenum, copper, silicon and aluminum, and the balance of iron element; the core layer comprises the following components: 30-50% of gas former, 20-30% of slag former, 15-25% of heat generating agent and 5-25% of metal powder; the gas former comprises 10-30% of sodium bicarbonate, 60-70% of calcium carbonate and 10-30% of basic copper carbonate by mass. The flux core in the welding wire can generate more gas during deep sea welding, one part of the gas is ionized to enter plasma to maintain electric arc, stable combustion of the gas is guaranteed, and the rest part of the gas enters the inside of bubbles to maintain or even increase the size of the bubbles so as to overcome the compression effect on the bubbles caused by deep sea high pressure, thereby improving the welding stability and improving the welding seam forming.
Description
Technical Field
The invention relates to component design and manufacturing of a flux-cored wire special for FCAW (flux-cored wire) by a deep sea wet method, and belongs to the technical field of welding wires.
Background
With the increasing consumption of energy resources, people begin to explore a large amount of natural resources in the ocean, which also puts higher requirements on the construction of ocean engineering structures, and underwater welding is used as an important means for constructing and maintaining ocean structures, and the welding quality directly determines the reliability of the structures. No matter the construction and installation of an offshore oil and gas exploitation platform or the maintenance and the laying of a submarine pipeline, the underwater welding technology plays no important role. Unlike onshore welding, underwater welded structures are subject to additional loads, in addition to operational loads, caused by storms, waves and tidal currents, as well as sea water erosion and grit wear. Therefore, improving the underwater welding quality and optimizing the underwater welding process are important problems to be solved currently.
According to the relation between a welding area and a water environment, underwater welding can be divided into dry welding, local dry welding and wet welding, the underwater dry welding is a method for welding a workpiece by completely isolating the workpiece from water through a dry normal-pressure or high-pressure air chamber, the cost is high, and therefore research on underwater dry arc welding is more focused on process exploration and optimization of a high-pressure dry method at present. The underwater local dry welding is a process for welding workpieces by establishing a tiny air chamber to isolate electric arcs from water, and most of the research on the process and the organization is focused at present. The underwater wet welding is a method for directly placing a workpiece and a welding gun in water for welding, arc combustion and droplet transition are carried out in bubbles generated by water decomposition and flux-cored wire gas making, and the bubbles separate a welding area from the water environment so as to ensure the welding process. The underwater wet welding method has the advantages of simple operation, flexible welding position, low construction cost and the like which are incomparable with other two methods, but the defects are obvious: the existence of welding bubbles can lead the welding process to become unstable, water flow continuously invades a welding area, the stability of welding electric arc is influenced, and the arc quenching phenomenon can be caused; the special underwater cooling condition also causes the problems of poor weld joint forming, large welding residual stress and the like in wet welding; the hydrogen generated by the decomposition of water tends to generate a large amount of pores and hydrogen-induced delayed cracking in the welded joint. According to different welding materials, underwater wet welding can be subdivided into underwater wet electrode arc welding and underwater wet Flux-cored wire welding, namely underwater FCAW (Flux-cored arc welding), the underwater wet electrode arc welding is that a region to be welded is completely exposed in water, a welder directly submerges into water and uses an underwater special welding rod to weld a workpiece, the early underwater wet electrode arc welding research mainly controls the quality of a welding seam by improving the components of a Flux coating, and the current research focuses on the influence of various physical parameters such as water depth, waterproof coating, electrode polarity and the like on the process and the performance. In the manufacturing process of the wet-process underwater welding rod, the design principle should be followed: in order to enable the welding rod to be smoothly welded by a overhead welding method, more iron powder is added into the coating, so that the coating has better conductivity and the production efficiency is improved; to reduce the solubility of hydrogen in the weld pool, more oxygen must be added to the electrode coating.
A curable material; potassium-sodium water glass is selected as a binder, and plastic powder is sprayed on the surface of the welding rod to serve as a waterproof layer. A special underwater welding rod patented in the United states is characterized in that a tubular sleeve made of synthetic resin is sleeved on the outer surface of a coated welding rod, and when the special underwater welding rod is used, gas is introduced between the outer surface of a coating of the welding rod and the sleeve to play a role of discharging water around an electric arc; the other is 7018S underwater welding rod, which is to coat a thin layer of aluminum powder on a coating, and the aluminum powder generates a large amount of gas at high temperature during underwater welding, thereby effectively draining water and protecting weld metal objects from being attacked by harmful substances. The aluminum powder has a particle size of approximately 0.0254um, and makes the welding rod have strong moisture resistance. The results of the moisture resistance test by the U.S. naval force show that the hydrogen content of the weld metal obtained under the condition of 100% humidity for 20 continuous days is still kept at a low value of 0.00023% (2.3 ppm), and the impact energy reaches 100J at-30 ℃, so that the 7018S underwater welding rod can be suitable for underwater welding of high-strength steel. 7018S underwater welding rod is a product of 90 U.S. years, is equivalent to 490 MPa-level AC/DC low-hydrogen welding rod, has good moisture absorption resistance, and can perform all-position underwater welding. Stephen Liu et al in the United states add Mn, ti, B and rare earth elements to the electrode coating, improve the welding performance during welding, and refine the microstructure of the weld joint. The special underwater welding rod in Soviet Union is EP-55 underwater welding rod, is only suitable for underwater welding of general structural steel, and has mechanical properties equivalent to T202 underwater welding rod in China. The types of the special underwater welding rods which have been developed domestically are TS202, TS203, TSH-1, TS208, TS306 and the like, and the maximum working water depth is generally 30m. Wherein, the welding power source of the T202 titanium calcium type welding rod adopts a direct current power source, and the coating has a water-resistant outer coating and can be used for all-position welding. The diameter of the welding rod is three kinds of phi 3.2, phi 4.0 and phi 5.0 mm. The sigma b of the weld metal is more than or equal to 410MPa. Weld metal chemistry (%): less than or equal to 0.12 percent of C, 0.30 to 0.60 percent of Mn, less than or equal to 0.25 percent of Si, less than or equal to 0.035 percent of S, and less than or equal to 0.04 percent of P. The joint strength sigma b is equivalent to that of a J422 welding rod, and the cold bending angle is about 90 degrees generally. TS208 is a special underwater welding rod recently developed by the Luoyang ship materials research institute and Shanghai Jinhui underwater engineering Co., ltd, and the main technical indexes of the TS208 welding rod are as follows. Mechanical properties: under the condition that the water depth is less than or equal to 30m, sigma b is more than or equal to 530MPa, and delta is more than or equal to 14 percent; the process performance is as follows: under the condition of seawater underwater welding, the welding arc is stable in combustion, small in splashing, good in welding seam forming, and excellent in re-striking performance, and the welding seam has no defects such as air holes and cracks. TS306 is a waterproof and gas-proof welding rod which adopts nickel-iron alloy as a core wire and has a double-layer coating. The outer layer is coated with a slagging agent and a waterproof agent, so that the sealing performance is strong, and the welding quality of the dissolved metal is guaranteed: the inner layer is coated with alloying agent and deoxidizing agent to ensure the stability of electric arc and the plasticity and metal components of welding seam. The welding rod can be used for all-position welding of structural steel and cast iron pipelines with water vapor or underwater. The tensile strength is as follows: σ b >490MPa, elongation: delta is more than or equal to 25 percent, is an ideal waterproof welding rod, can be used for both AC and DC, but is better for DC. In addition, the special high-efficiency underwater welding rod in the experimental research stage comprises a thick coating gravity welding rod in Japanese and Soviet Union research, and the welding is completed by moving a magnetic fixing support frame clamp to the welding rod.
The difference of the underwater wet FCAW is that a flux-cored wire is adopted, the outer layer of the wire is a steel strip, the inner layer of the wire is a flux core, the flux core in the wire is decomposed to generate gas and slag during welding, the gas is beneficial to maintaining the stability of bubbles and electric arcs, and the slag is beneficial to protecting a molten pool and preventing the molten pool from directly contacting with a water environment, so that the cooling speed of a welding joint is reduced, and the performance of a welding seam is improved. From the standpoint of welding materials, the most common welding with underwater manual flux-cored electrodes is currently performed, but requires divers to dive for the welding operation, each diver has limited time to work underwater and decreases with increasing depth of water. In addition, the length of the welding rod is limited, the welding rod needs to be frequently replaced in the welding process, the underwater construction time is prolonged, the production efficiency is low, and the quality is difficult to guarantee. Solid wire gas shielded welding, such as GMA welding (gas metal arc welding), suffers from arc instability, mainly manifested as arc breakage and metal particle spatter, at depths exceeding about 80 m. Compared with solid welding wire, the flux-cored welding wire has the advantages that the metal and welding material powder are matched more effectively in heat, the added welding flux can effectively improve the arc ionization condition and promote the stability of metal transition, and the flux-cored welding wire is used for deep sea welding and has more outstanding advantages. Of course, the welding efficiency is obviously improved compared with manual welding. The technology and principle of underwater flux-cored wire welding are originally proposed by Suo Union, the Barton welding research institute (Ukrainian) is a pioneer in the aspect, the underwater welding and cutting of the flux-cored wire are researched as early as 60 years, the rutile flux-cored wire PPS-AN1 is used for carrying out all-position welding on general low-carbon steel, the tensile strength of AN obtained joint reaches 450MPa, and the value is high enough as long as the weld metal is not AN alloy and does not contain carbon elements. The long-time application of the flux-cored wire PPS-AN1 shows that a welding joint with enough strength can be provided for low-carbon steel with the yield strength of 350MPa, but the joint plasticity cannot meet the requirement of AWS D3.6 standard on a B-grade joint.
Underwater flux-cored wire bonding has been slow to develop for nearly 40 years. The flux-cored wire is mainly used in some industries because the flux-cored wire is slow in development and not wide in application before the 80 s, and is gradually applied in some industries after the 80 s; secondly, the development of ocean resources is not strong, the previous underwater welding is mainly used for the maintenance of ocean engineering and ships and the welding of secondary parts of the structure, and the welding of important parts is designed to be carried out on land consciously. The requirements on the production efficiency and the quality of underwater welding are not high, and the requirements can be met by using a coated electrode for manual welding. With the continuous and deep development of ocean resources, particularly petroleum and natural gas resources, of all countries in the world, the large-scale construction of ocean engineering begins, and the underwater welding can reduce the complexity of ocean engineering structure design and shorten the engineering construction period, so that the underwater welding is used more and more frequently, and higher requirements are provided for the efficiency and the quality of the underwater welding. Compared with the developed countries in the west, how to rapidly improve the technical level and innovation capability of the underwater wet welding material in China is still lagged, and a great challenge is provided for researchers.
The invention also mainly aims at the welding process to carry out design, in a shallow water environment, the water pressure above the workpiece is small, so that the bubble space is relatively large, the welding process is relatively stable, and the welding quality is high. At present, the research of developing wet FCAW and carrying out process optimization on the FCAW is less aiming at the deep sea environment, and the research is mainly focused on wet flux-cored wire welding in water depth below 80 m. For the flux-cored wire, the most important component is the flux core inside the flux-cored wire, most of the currently researched flux cores are rutile type flux cores, and proper amounts of iron powder and SiO are added 2 、Al 2 O 3 The flux-cored wire has the advantages that the flux-cored wire has proper slag composition, has better adaptability under the shallow water working condition, but gas generated by the flux core under the deep sea environmentThe body can not make up for the bubble compression that the high pressure leads to for the welding is unstable, frequently produces the broken arc, has seriously influenced welding quality, and simultaneously, under the deep sea condition in the ocean, the sea water has stronger corrosivity, also puts forward certain requirement to the corrosion resistance of welding joint, because this life that involves the welding joint and because the risk problem that corrodes and bring. Therefore, in order to apply the underwater wet FCAW process to a deep sea environment to obtain a welding joint with good quality, increase the size of bubbles under a deep sea welding condition, improve the stability of the bubbles and improve the corrosion resistance of the welding joint, which are the most important problems currently faced, it is necessary to provide a flux-cored wire special for the deep sea wet FCAW for research.
Disclosure of Invention
Aiming at the defects of the prior art and solving the problems of the FCAW, the flux-cored wire special for deep sea wet welding is provided, so that the flux core in the wire can generate more gas during deep sea welding, one part of the gas is ionized to enter plasma to maintain electric arc, the stable combustion of the gas is ensured, the other part of the gas enters bubbles to maintain or even increase the size of the bubbles, the compression effect of the bubbles caused by deep sea high pressure is overcome, the welding stability is improved, and the welding seam forming is improved. Meanwhile, the welding wire can greatly improve the corrosion resistance of the welding seam, prolong the service life of a welding joint in a deep sea environment and reduce the risk of accidents of an ocean structure and the maintenance cost.
The technical scheme of the invention is as follows:
the invention respectively designs the components of the outer steel belt and the inner flux core of the flux-cored wire so as to realize different effects. First, for the outer steel strip, the present invention does not use conventional low carbon steel, but considers using stainless steel having good corrosion resistance. For stainless steel, it has such excellent properties because it contains a higher content of beneficial alloying elements than ordinary low carbon steel. The beneficial effects of various alloying elements and the design content of the invention are explained in detail as follows:
chromium: the hardenability and the wear resistance of the steel can be improved; can generate a passive film to block the anode reaction, improve the electrode potential of the steel and improve the seawater corrosion resistance and oxidation resistance of the steel;
titanium: the grain structure of the steel can be refined, so that the strength and the toughness of the steel are improved. In stainless steel, titanium can eliminate or reduce the intergranular corrosion phenomenon of steel, and can improve the capability of resisting atmospheric and seawater corrosion of steel when being used in combination with other elements;
nickel: can improve the strength and the toughness of the steel and improve the hardenability. When the content is high, some physical properties of steel and alloy can be obviously changed, and the corrosion resistance of the steel is improved. Nickel makes the steel not only acid resistant, but also alkali resistant, corrosion resistant to atmosphere and salt. However, the influence of nickel on the corrosion resistance of stainless steel can be fully displayed only when the nickel is matched with chromium, because the low-carbon nickel steel needs to obtain a pure austenite structure and the nickel content is required to reach 24 percent; in order to change the corrosion resistance of steel in some medium, the nickel content must be over 27%, so that nickel can not be formed into stainless steel alone, and 9% of nickel can be added into the steel containing 18% of chromium, so that the steel can obtain single austenite structure at normal temp. and can obviously raise the corrosion resistance of steel to non-oxidizing medium (for example dilute sulfuric acid, hydrochloric acid and phosphoric acid).
Carbon: the double nature of the carbon in stainless steel- -the content of carbon in stainless steel and the form of its distribution, largely controls the properties and structure of stainless steel: on one hand, carbon is a stable austenite element, has a great action degree which is about 30 times that of nickel, and (martensite) stainless steel with high carbon content can completely accept quenching strengthening, so that the strength of the stainless steel can be greatly improved in the aspect of mechanical property; on the other hand, because of the high affinity of carbon and chromium, seventeen times the amount of carbon is consumed in stainless steel to combine chromium with it to form chromium carbide. As the carbon content in steel increases, more chromium forms carbides with carbon, thereby significantly reducing the corrosion resistance of steel. Therefore, the role of carbon in stainless steel is mutually contradictory in terms of both strength and corrosion resistance. In practical application, in order to achieve the purpose of corrosion resistance, the carbon content of stainless steel is generally low, mostly about 0.1%, and in order to further improve the corrosion resistance of steel, especially the intergranular corrosion resistance, ultralow carbon stainless steel is often adopted, and the carbon content is 0.03% or even lower;
niobium: niobium is a strong carbide former with much greater affinity for carbon than chromium, and the addition of niobium to steel causes the carbon in the steel to form carbides with niobium first, but not with chromium, thereby ensuring that intergranular corrosion does not occur near the grain boundaries due to chromium depletion. Therefore, niobium is often used to fix carbon in steel, improve the resistance of stainless steel to intergranular corrosion, and improve the weldability of steel. The mechanism of action of niobium is substantially identical to that of titanium, which is added in an amount corresponding to the carbon content, and generally, titanium is added in an amount of 5 times the carbon content and niobium is added in an amount of 8 times the carbon content.
Molybdenum and copper: the corrosion resistance of some stainless steel to some mediums can be improved, and the corrosion resistance of molybdenum and copper to corrosive mediums such as sulfuric acid, acetic acid and the like can be improved. Molybdenum also significantly improves corrosion resistance in chloride ion-containing media (e.g., hydrochloric acid) and organic acids.
Silicon and aluminum: can improve the oxidation resistance of the stainless steel.
Similarly, the flux core of the welding wire is subjected to component design:
the flux-cored wire is considered to release a large amount of gas in the deep sea welding process so as to maintain and even increase the size of arc bubbles, and meanwhile, as the water flow in the deep sea environment has strong cooling effect on a welding wire, an electric arc and a molten pool, a part of heat generating agent is required to be added to accelerate the melting of the welding wire so as to promote gas making and slag making, based on the consideration, the flux-cored wire designed by the invention has the following components aiming at the effects of various elements:
a flux-cored wire special for FCAW (flux cored arc welding) in a deep sea wet method comprises an outer steel belt and an inner flux core,
the outer layer steel belt material is stainless steel, and comprises the following materials: characterized by mass percent, carbon content: < =0.025%, chromium content: 17.5% -20.5%, nickel content: 8.5% -10.5%, titanium content: 0.13% -0.15%, niobium content: 0.2% -0.25%, molybdenum content: 1.5% -2.5%, copper content: 1.5% -2.5%, silicon content: 0.7% -1.2%, aluminum content: 0.7 to 1.2 percent of iron element;
the inner core comprises the following components (characterized by mass percent): 30-50% of gas former, 20-30% of slag former, 15-25% of heat generating agent and 5-25% of metal powder; wherein, the components of the gas former are sodium bicarbonate, calcium carbonate and basic copper carbonate, wherein, the sodium bicarbonate accounts for 10 to 30 percent of the gas former by mass, the calcium carbonate accounts for 60 to 70 percent, and the basic copper carbonate accounts for 10 to 30 percent.
The chemical formula of the generated gas generated by the thermal decomposition of the three gas-forming agents is as follows:
preferably, the slagging agent comprises rutile and fluorite, and the mass ratio of the rutile to the fluorite is 1.
Preferably, the heat generating agent comprises Al-NaF and a silicon-carbon heat generating agent, and the Al-NaF mixture has two strong exothermic reactions in the heating process, which respectively occur in the temperature ranges of 300-500 ℃ and 800-1150 ℃. The exothermic reaction at low temperatures (300 ℃ C. To 500 ℃ C.) is due to decomposition in this temperature range or due to partial oxidation of NaF, while the exothermic reaction at high temperatures (800 ℃ C. To 1150 ℃ C.) is due to strong oxidation of Al. The silicon-carbon heating agent is prepared by mixing ferrosilicon powder and carburant powder and then pressing balls, and is added in the early stage of smelting in a converter and an electric furnace to provide heat and accelerate slagging. The heating effect of the silicon-carbon heating agent is ensured by the components of the silicon-carbon heating agent, and the used raw materials have obvious environment-friendly effect. In the heat generating agent, the mass fraction of Al-NaF is 60% -70%, and the rest is the silicon-carbon heating agent.
Preferably, the metal powder comprises the following elements: iron, copper, aluminum, tungsten, magnesium and manganese, wherein the iron, the copper and the aluminum respectively account for 25-30 percent, and the tungsten, the magnesium and the manganese respectively account for 5-10 percent, and are characterized by mass percent.
The welding working condition aimed by the invention is not only underwater, but also deep water ocean condition, the working condition is more complex, the welding process is more unstable, and therefore, the requirement on the design of welding rod components is correspondingly higher.
Preferably, all the components of the inner-layer flux core are added in a powder form, and in order to improve the performance of the welding material, the invention puts forward the following requirements on the granularity of each component: the gas former, the slag former and the metal powder are 60-80 meshes, and the heat generating agent is 80-100 meshes.
Preferably, other parameters related to the deep-sea wet-process FCAW flux-cored wire designed by the invention are as follows: the overall diameter of the flux-cored wire is 2mm to 2.5mm, and more preferably 2.2mm.
Preferably, the filling rate of the inner flux core of the flux-cored wire is 35-40%, and the filling rate is characterized by mass percent. The protection effect of the self-protection flux-cored wire comes from the flux core, so that the specific gravity of the flux core is set to be 35-40%.
Preferably, the width of the outer steel strip is 8.5mm, and the thickness is 0.4mm.
A preparation method for preparing the flux-cored wire special for the deep sea wet FCAW comprises the following steps:
(1) Taking the components of the inner-layer flux core in corresponding proportion, including a gas former, a slag former, a heat generating agent and metal powder, respectively grinding the components to corresponding granularity according to requirements, putting the components into a powder mixer for 6 hours, and uniformly mixing the components;
(2) Rolling the outer steel strip into a U shape, filling the powder into the U-shaped steel strip, wherein the filling rate of the flux-cored wire is 35-40%;
(3) And (3) gradually thinning the welding wire by passing the steel strip filled with the flux core through a wire drawing die until the required diameter of the welding wire is 2-2.5mm.
The invention has the beneficial effects that:
(1) The invention reasonably designs the components of the flux-cored wire steel belt, considers the use of stainless steel, and the stainless steel metal enters a molten pool as the main part of molten drops in the welding process, is fused with the molten pool metal, and forms a welding joint after cooling, thereby greatly improving the corrosion resistance of the welding joint in the ocean deep water environment, greatly prolonging the service life of an ocean welding structural member and greatly saving the equipment maintenance cost.
(2) The flux-cored wire reasonably designs the flux-cored components of the flux-cored wire, mainly comprises the gas former, the slag former, the heat generator and the metal powder, and ensures that the volume of welding bubbles can be maintained or even expanded when welding is carried out in deep sea by adding a large amount of the gas former, so that the welding process is more stable, and the welding seam is better formed. Meanwhile, the heating agent is added, so that the melting of the welding wire can be accelerated, the gas making and slag making processes are promoted, and the protection effect on the welding process is enhanced. The existence of the metal powder can improve the electric conductivity and the thermal conductivity of the flux core, and has positive significance for improving the effective heat input of welding, especially under the condition of rapidly accelerating the heat dissipation in a deep sea environment.
In conclusion, the flux-cored wire special for the deep sea wet FCAW is suitable for welding in a deep sea environment, and can ensure that a welding joint with excellent mechanical property, good corrosion resistance and longer service life can be obtained by welding under the deep sea condition.
Detailed Description
The present invention is further illustrated by, but not limited to, the following examples.
Example 1:
a flux-cored wire special for FCAW (flux-cored arc welding) in a deep sea wet method comprises an outer steel belt and an inner flux core; the outer layer steel belt is stainless steel, and is characterized by comprising, by mass, 0.025% of carbon, 18% of chromium, 9.0% of nickel, 0.14% of titanium, 0.22% of niobium, and molybdenum: 2.0%, copper content: 2.0 percent of silicon, 1.0 percent of aluminum and the balance of iron; the width of the outer layer steel belt is 8.5mm, and the thickness is 0.4mm.
The inner layer flux core comprises 40% of gas making agent, 25% of slag making agent, 20% of heat generating agent and 15% of metal powder, and is characterized by mass percent; the gas-generating agent comprises 20% of sodium bicarbonate, 60% of calcium carbonate and 20% of basic copper carbonate; the slag former comprises rutile and fluorite, the proportion of the rutile to the fluorite is 1, and the slag former is characterized by mass percent; the heat generating agent comprises 65 percent of Al-NaF and 35 percent of silicon-carbon heating agent; the metal powder contains 25% of iron, aluminum and copper, 5% of tungsten and 10% of magnesium and manganese; the gas former, the slag former and the metal powder are 70 meshes, and the heat generating agent is 90 meshes; the diameter of the flux-cored wire is 2.2mm, and the filling rate of the flux core in the flux-cored wire is 35%.
Example 2:
a flux-cored wire special for FCAW (flux-cored arc welding) in a deep sea wet method comprises an outer steel belt and an inner flux core; the outer steel strip was identical to example 1; the inner layer flux core comprises 30% of gas forming agent, 25% of slag forming agent, 20% of heat generating agent and 25% of metal powder; the gas generant composition was consistent with example 1; the slag former composition was identical to example 1; the thermogenic agent composition is in accordance with example 1; the metal powder composition was consistent with example 1; the core particle size was consistent with example 1; the diameter of the flux-cored wire and the flux-cored filling rate are consistent with those of the embodiment 1.
Example 3:
a flux-cored wire special for FCAW (flux-cored wire) by a deep sea wet method comprises an outer steel belt and an inner flux core; the outer steel strip was identical to example 1; the inner layer flux core comprises 50% of gas former, 25% of slag former, 20% of heat generating agent and 5% of metal powder; the gas generant composition was consistent with example 1; the slag former composition was consistent with example 1; the thermogenic agent composition is in accordance with example 1; the metal powder composition was consistent with example 1; the core particle size was consistent with example 1; the diameter and the flux core filling rate of the flux-cored wire are consistent with those of the embodiment 1.
Example 4:
the flux-cored wire special for FCAW (flux-cored wire) by a deep sea wet method comprises an outer steel belt and an inner flux core, wherein the outer steel belt is made of stainless steel and comprises the following materials: characterized by mass percent, carbon content: 0.024%, chromium content: 17.5%, nickel content: 8.5%, titanium content: 0.13%, niobium content: 0.2%, molybdenum content: 1.5%, copper content: 1.5%, silicon content: 0.7%, aluminum content: 0.7 percent of iron element and the balance of iron element; the inner core comprises the following components (characterized by mass percent): 45% of gas former, 20% of slag former, 15% of heat generating agent and 20% of metal powder; the gas former comprises the components of sodium bicarbonate, calcium carbonate and basic copper carbonate, wherein the sodium bicarbonate accounts for 15 percent of the gas former by mass, the calcium carbonate accounts for 70 percent of the gas former by mass, and the basic copper carbonate accounts for 15 percent of the gas former by mass.
Example 5:
the flux-cored wire special for FCAW (flux-cored wire) by a deep sea wet method comprises an outer steel belt and an inner flux core, wherein the outer steel belt is made of stainless steel and comprises the following materials: characterized by mass percent, carbon content: 0.025%, chromium content: 20.5%, nickel content: 10.5%, titanium content: 0.15%, niobium content: 0.25%, molybdenum content: 2.5%, copper content: 2.5%, silicon content: 1.2%, aluminum content: 1.2 percent, and the balance of iron element; the inner core comprises the following components (characterized by mass percent): 30% of gas former, 30% of slag former, 25% of heat generating agent and 15% of metal powder; the gas former comprises the components of sodium bicarbonate, calcium carbonate and basic copper carbonate, wherein the sodium bicarbonate accounts for 30 percent of the gas former by mass, the calcium carbonate accounts for 60 percent of the gas former by mass, and the basic copper carbonate accounts for 10 percent of the gas former by mass.
Example 6:
the flux-cored wire special for FCAW (deep sea Wet Process) comprises an outer steel belt and an inner flux core, and comprises the components described in example 5, except that the components of a gas generating agent comprise sodium bicarbonate, calcium carbonate and basic copper carbonate, wherein the sodium bicarbonate accounts for 10% of the gas generating agent by mass, the calcium carbonate accounts for 60% of the gas generating agent by mass, and the basic copper carbonate accounts for 30% of the gas generating agent by mass.
Example 7:
a flux-cored wire special for FCAW (deep sea Wet Process) comprises an outer steel belt and an inner flux core, and comprises the components as described in example 1, wherein the components are as follows, except that a gas former, a slag former and metal powder are 60 meshes, and a heat generating agent is 80 meshes.
Example 8:
the flux-cored wire special for FCAW (deep sea Wet Process) comprises an outer steel belt and an inner flux core, and comprises the components as described in example 1, except that a gas former, a slag former and metal powder are 80 meshes, and a heat generator is 100 meshes.
Example 9:
a flux-cored wire special for FCAW (deep sea Wet Process) comprises an outer steel belt and an inner flux core, and the components of the flux-cored wire are as described in example 1, except that the diameter of the flux-cored wire is 2mm.
Example 10:
the flux-cored wire special for FCAW (deep sea Wet Process) comprises an outer steel belt and an inner flux core, and comprises the components as described in example 1, except that the diameter of the flux-cored wire is 2.5mm, and the filling rate of the inner flux core of the flux-cored wire is 40%.
Example 11:
the preparation method of the flux-cored wire special for deep sea wet FCAW in the embodiment 1 comprises the following steps:
(1) Taking the components of the inner-layer flux core in corresponding proportion, including the gas former, the slag former, the heat generating agent and the metal powder, respectively grinding the components to corresponding granularity according to requirements, putting the components into a powder mixer for 6 hours, and uniformly mixing the components;
(2) Rolling the outer steel strip into a U shape, filling the powder, wherein the filling rate of the flux-cored wire is 35%;
(3) And (3) gradually thinning the welding wire by passing the steel strip filled with the flux core through a wire drawing die until the required diameter of the welding wire is 2.2mm.
Comparative example 1:
a flux-cored wire special for FCAW (flux-cored wire) by a deep sea wet method comprises an outer steel belt and an inner flux core; the outer layer steel belt is low-carbon steel, and the carbon content is 0.04%; the core composition was consistent with example 1; the core particle size was consistent with example 1; the diameter and the flux core filling rate of the flux-cored wire are consistent with those of the embodiment 1.
Comparative example 2:
a flux-cored wire special for FCAW (flux-cored arc welding) in a deep sea wet method comprises an outer steel belt and an inner flux core; the outer steel strip was identical to example 1; the flux core comprises the components of no gas former, 50% of slag former, 30% of heat generating agent and 20% of metal powder; the slag former composition was consistent with example 1; the thermogenic agent composition is in accordance with example 1; the metal powder composition was in accordance with example 1; the core particle size was consistent with example 1; the diameter and the flux core filling rate of the flux-cored wire are consistent with those of the embodiment 1.
The welding wires are manufactured according to the following procedures:
1. taking the components of the medicine core in corresponding proportion, including gas-forming agent (not added), slag-forming agent, heat-producing agent and metal powder, respectively grinding the components to corresponding granularity according to requirements, putting the components into a powder mixer for 6h, and uniformly mixing the components;
2. rolling the steel strip into a U shape, and filling the medicinal powder;
3. and (3) passing the steel strip filled with the flux core through a wire drawing die, and gradually drawing the welding wire to be thin until the diameter of the welding wire is required.
Examples of the experiments
By using the flux-cored wire special for the deep-sea wet-process FCAW, the invention develops a deep-water wet-process FCAW welding test, the welding workpiece is a steel plate AH36 special for ships and ocean engineering, and the welding parameters are shown in Table 1.
TABLE 1 summary of welding parameters
| Welding parameters | Welding current | Arc voltage | Wire feed speed | Welding speed | Dry elongation | Depth of welding water |
| Numerical value | 250A | 32V | 5.5m/min | 160m/min | 15mm | 200m |
And (3) carrying out performance test on the stable welding seam of the postweld intercepted part, wherein the performance test comprises the following performances: seawater corrosion resistance (3.5% NaCl solution immersion test), tensile strength, maximum elongation, zero degree impact toughness, the measured performance results of each example are shown in Table 2:
TABLE 2 comparison of the properties of the welding wires
The performance of the unwelded workpiece measured by the experiment is 0.58mm/a seawater corrosion resistance, the tensile strength is 540MPa, the maximum elongation is 23%, and the zero-degree impact toughness is 31.0J.
Meanwhile, the powder ratio of the welding wire also has great influence on the performance of the welding joint, particularly the ratio of the gas former is 40%, the obtained welding joint has excellent comprehensive performance, as shown in example 1, when the ratio is reduced to 30% or increased to 50%, the performance is slightly reduced but not large compared with that of example 1, and the ratio is far higher than that of the base metal, which shows that the flux core designed by the invention has reasonable component ratio. And if the gas-forming agent is not added, namely the proportion is set to be 0, the performance of the obtained welding joint is seriously deteriorated, as shown in a comparative example 2, in the aspect of corrosion resistance, because the outer steel band of the welding wire is still stainless steel, the change is not large, but the strength and the plastic toughness of the welding wire are obviously reduced compared with those of the previous embodiment and are lower than those of the base metal, and because the gas-forming agent is not added, no gas is supplemented into welding bubbles during welding in a deep sea environment, the bubble volume is seriously shrunk under the action of deep water and high pressure, a large amount of seawater enters a welding area, so that frequent arc breakage is caused, and meanwhile, the molten drop transition is also seriously influenced, so that the quality of the welding joint is very poor. It can be seen that under the working condition of deep sea welding, the addition of the gas-forming agent has a very positive effect on the improvement of the welding quality.
In conclusion, the deep-sea wet FCAW flux-cored wire designed by the invention is suitable for welding in a marine environment with high corrosivity and high water pressure, and can obtain a high-quality welding joint with strong corrosion resistance and excellent mechanical properties.
Claims (7)
1. A flux-cored wire special for FCAW (flux-cored arc welding) by a deep sea wet method is characterized by comprising an outer steel belt and an inner flux core,
the outer layer steel belt material is stainless steel, and comprises the following materials: characterized by mass percent, carbon content: < =0.025%, chromium content: 17.5% -20.5%, nickel content: 8.5% -10.5%, titanium content: 0.13% -0.15%, niobium content: 0.2% -0.25%, molybdenum content: 1.5% -2.5%, copper content: 1.5% -2.5%, silicon content: 0.7% -1.2%, aluminum content: 0.7 to 1.2 percent of iron element and the balance of iron element;
the inner layer flux core comprises the following components in percentage by mass: 30-50% of gas former, 20-30% of slag former, 15-25% of heat generating agent and 5-25% of metal powder; wherein, the components of the gas former are sodium bicarbonate, calcium carbonate and basic copper carbonate, wherein, the sodium bicarbonate accounts for 10 to 30 percent of the gas former by mass, the calcium carbonate accounts for 60 to 70 percent of the gas former by mass, and the basic copper carbonate accounts for 10 to 30 percent of the gas former by mass; the slag former comprises rutile and fluorite, and the mass ratio of the rutile to the fluorite is 1; the heat generating agent comprises Al-NaF and a silicon-carbon heating agent, the silicon-carbon heating agent is prepared by mixing ferrosilicon powder and carburant powder and then pressing balls, the mass fraction of the Al-NaF is 60% -70%, and the balance is the silicon-carbon heating agent; the metal powder comprises the following elements: iron, copper, aluminum, tungsten, magnesium and manganese, wherein the iron, the copper and the aluminum respectively account for 25-30 percent, and the tungsten, the magnesium and the manganese respectively account for 5-10 percent, and are characterized by mass percent.
2. The flux-cored wire special for deep sea wet FCAW (flux cored wire) according to claim 1, wherein various components of the flux core at the inner layer are added in a powder form, a gas former, a slag former and metal powder are 60-80 meshes, and a heat generating agent is 80-100 meshes.
3. The flux-cored wire special for deep sea wet FCAW of claim 1, wherein the overall diameter of the flux-cored wire is 2mm-2.5mm.
4. The flux-cored wire special for deep sea wet FCAW of claim 3, wherein the flux-cored wire has an overall diameter of 2.2mm.
5. The flux-cored wire special for deep sea wet FCAW (flux-cored wire) of claim 1, wherein the filling rate of the flux core in the flux-cored wire is 35-40% and is characterized by mass percent.
6. The flux-cored wire special for deep sea wet process FCAW according to claim 1, wherein the width of the outer steel strip is 8.5mm, and the thickness of the outer steel strip is 0.4mm.
7. A preparation method for preparing the flux-cored wire special for deep sea wet process FCAW according to any one of claims 1 to 6, comprising the following steps:
(1) Taking the components of the inner-layer flux core in corresponding proportion, including a gas former, a slag former, a heat generating agent and metal powder, respectively grinding the components to corresponding granularity according to requirements, putting the components into a powder mixer for 6 hours, and uniformly mixing the components;
(2) Rolling the outer steel belt into U shape, and filling the medicinal powder;
(3) And (4) passing the steel strip filled with the flux core through a wire drawing die, and gradually drawing the welding wire to be thin until the diameter of the welding wire is required.
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| Application Number | Priority Date | Filing Date | Title |
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| CN202210184966.XA CN114505615B (en) | 2022-02-28 | 2022-02-28 | Flux-cored wire special for deep sea wet FCAW and preparation method |
| PCT/CN2023/078683 WO2023160718A1 (en) | 2022-02-28 | 2023-02-28 | Special flux-cored welding wire for deep-sea wet fcaw and preparation method therefor |
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| CN202210184966.XA CN114505615B (en) | 2022-02-28 | 2022-02-28 | Flux-cored wire special for deep sea wet FCAW and preparation method |
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| CN114505615B (en) * | 2022-02-28 | 2023-01-17 | 山东大学 | Flux-cored wire special for deep sea wet FCAW and preparation method |
Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| SU1299755A1 (en) * | 1985-12-12 | 1987-03-30 | Ленинградский Кораблестроительный Институт | Compound for external layer of two-layer electrode coating |
| CN102428056A (en) * | 2009-05-21 | 2012-04-25 | 株式会社大赛璐 | Gas generant composition |
| CN103084761A (en) * | 2013-02-27 | 2013-05-08 | 哈尔滨工业大学（威海） | Self-protection core welding stick used for underwater wet welding |
| CN104722960A (en) * | 2015-03-24 | 2015-06-24 | 江苏科技大学 | High-efficiency heat production flux-cored cutting wire for underwater wet-type arc cutting and preparation method thereof |
| CN109081766A (en) * | 2018-08-29 | 2018-12-25 | 湖北航天化学技术研究所 | A kind of Al-NaF hybrid fuel and its preparation method and application |
| CN111571066A (en) * | 2020-04-17 | 2020-08-25 | 江苏大学 | Low-hydrogen stainless steel self-protection flux-cored wire suitable for underwater environment |
Family Cites Families (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5236517A (en) * | 1992-08-28 | 1993-08-17 | Electric Power Research Institute | Flux formulation for underwater wet flux-cored arc welding of nickel-based and austenitic stainless steels |
| CN110497113B (en) * | 2019-08-23 | 2021-06-01 | 哈尔滨工业大学（威海） | Low-energy-consumption multipurpose underwater wet welding self-protection flux-cored wire |
| CN114505615B (en) * | 2022-02-28 | 2023-01-17 | 山东大学 | Flux-cored wire special for deep sea wet FCAW and preparation method |
-
2022
- 2022-02-28 CN CN202210184966.XA patent/CN114505615B/en active Active
-
2023
- 2023-02-28 WO PCT/CN2023/078683 patent/WO2023160718A1/en unknown
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| SU1299755A1 (en) * | 1985-12-12 | 1987-03-30 | Ленинградский Кораблестроительный Институт | Compound for external layer of two-layer electrode coating |
| CN102428056A (en) * | 2009-05-21 | 2012-04-25 | 株式会社大赛璐 | Gas generant composition |
| CN103084761A (en) * | 2013-02-27 | 2013-05-08 | 哈尔滨工业大学（威海） | Self-protection core welding stick used for underwater wet welding |
| CN104722960A (en) * | 2015-03-24 | 2015-06-24 | 江苏科技大学 | High-efficiency heat production flux-cored cutting wire for underwater wet-type arc cutting and preparation method thereof |
| CN109081766A (en) * | 2018-08-29 | 2018-12-25 | 湖北航天化学技术研究所 | A kind of Al-NaF hybrid fuel and its preparation method and application |
| CN111571066A (en) * | 2020-04-17 | 2020-08-25 | 江苏大学 | Low-hydrogen stainless steel self-protection flux-cored wire suitable for underwater environment |
Non-Patent Citations (1)
| Title |
|---|
| 水下湿法焊接材料的研究进展;刘多 等;《焊接》;20121225(第12期);第18-22页 * |
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