阅读说明：本技术 T2铜与304不锈钢焊接用自保护药芯焊丝及制备方法 (Self-protection flux-cored wire for welding T2 copper and 304 stainless steel and preparation method thereof ) 是由 张敏 张云龙 李静 王刚 郭宇飞 于 2019-09-03 设计创作，主要内容包括：本发明公开了T2铜与304不锈钢焊接用自保护药芯焊丝,包括药芯和焊皮,其中药芯质量百分比由以下组元组成：镍粉：50％～60％,硅粉：2％～9％,钛粉：4％～8％,硼粉：2％～4％,钛白粉：1％～4％,金红石粉：10％～13％,硅铁粉：1％～2％,铝镁合金粉：2％～5％,四氟化铈：1％～2％,氟化钙：5％～9％,碳酸锂：1％～3％,锆英砂：1％～5％,以上组分质量百分比之和为100％。该药芯焊丝解决了目前铜和钢焊接时结合界面熔合性差且易产生焊接裂纹的问题。还提供了焊丝的制备方法,按照上述配方称取原料,然后将各原料粉末混合、以纯铜带为焊皮,并依次通过模具将药芯焊丝减径至0.8mm-1.6mm。(The invention discloses a self-protection flux-cored wire for welding T2 copper and 304 stainless steel, which comprises a flux core and a welding skin, wherein the flux core comprises the following components in percentage by mass: nickel powder: 50% -60%, silicon powder: 2% -9%, titanium powder: 4% -8%, boron powder: 2% -4%, titanium dioxide: 1% -4%, rutile powder: 10% -13%, ferrosilicon powder: 1-2%, aluminum magnesium alloy powder: 2% -5%, cerium tetrafluoride: 1% -2%, calcium fluoride: 5% -9%, lithium carbonate: 1% -3%, zircon sand: 1 to 5 percent, and the sum of the mass percentages of the components is 100 percent. The flux-cored wire solves the problems that the fusion property of a bonding interface is poor and welding cracks are easy to generate when copper and steel are welded at present. The preparation method of the flux-cored wire is also provided, the raw materials are weighed according to the formula, then the raw material powders are mixed, the pure copper strip is used as a welding skin, and the diameter of the flux-cored wire is reduced to 0.8mm-1.6mm through a die in sequence.)

The self-protection flux-cored wire for welding the T2 copper and the 304 stainless steel is characterized by comprising a flux core and a welding skin, wherein the flux core consists of the following components in percentage by mass: nickel powder: 50% -60%, silicon powder: 2% -9%, titanium powder: 4% -8%, boron powder: 2% -4%, titanium dioxide: 1% -4%, rutile powder: 10% -13%, ferrosilicon powder: 1-2%, aluminum magnesium alloy powder: 2% -5%, cerium tetrafluoride: 1% -2%, calcium fluoride: 5% -9%, lithium carbonate: 1% -3%, zircon sand: 1 to 5 percent, and the sum of the mass percentages of the components is 100 percent.

2. The self-shielded flux-cored welding wire for welding of T2 copper and 304 stainless steel of claim 1, wherein the welding skin is a pure copper strip.

3. The self-shielded flux-cored welding wire for welding T2 copper and 304 stainless steel as claimed in claim 1, wherein the filling ratio of the flux-cored powder in the flux-cored welding wire is 22-28 wt.%.

4. The self-shielded flux-cored wire for welding T2 copper and 304 stainless steel as claimed in claim 1, wherein the diameter of the flux-cored wire is 0.8mm to 1.6 mm.

The preparation method of the self-shielded flux-cored wire for welding the T2 copper and the 304 stainless steel is characterized by comprising the following specific steps of:

step 1: respectively weighing the medicine core powder according to the required mixture ratio by mass percent: nickel powder: 50% -60%, silicon powder: 2% -9%, titanium powder: 4% -8%, boron powder: 2% -4%, titanium dioxide: 1% -4%, rutile powder: 10% -13%, ferrosilicon powder: 1-2%, aluminum magnesium alloy powder: 2% -5%, cerium tetrafluoride: 1% -2%, calcium fluoride: 5% -9%, lithium carbonate: 1% -3%, zircon sand: 1-5 percent, the sum of the mass percentages of the components is 100 percent;

step 2: mixing the rutile powder, the titanium dioxide, the calcium fluoride, the lithium carbonate, the cerium tetrafluoride and the zircon sand weighed in the step 1 into mixed powder A, adding a certain amount of sodium water glass adhesive into the mixed powder A for fully kneading, uniformly mixing, fully sintering the mixed powder A in a heating furnace, and grinding after sintering to obtain mixed powder B;

and step 3: putting the nickel powder, the silicon powder, the titanium powder, the ferrosilicon powder, the aluminum-magnesium alloy powder and the boron powder weighed in the step 1 and the mixed powder B prepared in the step 2 into an automatic powder mixer for mixing to obtain flux-cored powder, wherein the powder mixing time is 20-24 hours, the obtained uniform flux-cored powder is placed into a vacuum ring furnace for heating to 250-350 ℃, and the temperature is kept for 2-7 hours for later use;

and 4, step 4: placing the pure copper strip with the burr side facing upwards at a strip placing turntable of a wire drawing machine, enabling the copper strip cleaned by alcohol to pass through a U-shaped roller, filling the flux core powder mixed in the step 3 into the formed U-shaped copper strip, sealing the U-shaped copper strip by a closed groove, and utilizing the apertureFinishing a first drawing process for a reducing die with the diameter of 2.5mm, standing the welding wire for 4 hours, releasing stress, and finally reducing the diameter of the flux-cored wire to 0.8-1.6 mm through the die in sequence;

and 5: and (4) straightening the flux-cored wire obtained in the step (4) by a wire winding machine, coiling the flux-cored wire into a disc, sealing and packaging the disc, and wiping oil stains on the surface of the flux-cored wire clean by using alcohol or acetone solution.

6. The self-shielded flux-cored wire for welding T2 copper and 304 stainless steel as claimed in claim 5, wherein the sodium water glass binder in step 2 is 22-25% of the total mass of powder A.

7. The self-shielded flux-cored wire for welding T2 copper and 304 stainless steel as claimed in claim 5, wherein the sintering temperature is 600-750 ℃ and the sintering time is 4-5 hours in step 2, and the particle size of the mixed powder B is 80-100 mesh.

8. The self-shielded flux cored welding wire for welding T2 copper and 304 stainless steel as claimed in claim 5, wherein the filling rate of the flux cored powder in the flux cored welding wire in step 4 is 22-28 wt.%.

Technical Field

The invention belongs to the technical field of metal material welding, and particularly relates to a self-shielded flux-cored wire for welding T2 copper and 304 stainless steel, and a preparation method of the self-shielded flux-cored wire.

Background

With the rapid development of modern industry, the application of any precious and advanced material is not limited to the characteristics of self performance, the development direction of the material gradually turns to multi-functionalization, and more strict requirements are provided for welded structural members. T2 red copper, one of the most widely used precious metals in industrial applications, is generally used for manufacturing conductive parts, heat exchangers, chemical vessels, nuclear waste storage containers, and the like because of its excellent electrical conductivity, thermal conductivity, and corrosion resistance, but cannot exert the performance advantage of the material to the utmost extent due to its low strength, high price, and the like. As the metal material with the largest use amount in the industry, the steel has the advantages of high strength, good ductility and toughness, low cost and the like. Generally, steel is selected as the high-voltage side of a large-scale power transformer to greatly reduce workpiece loss and overheating phenomena of the transformer caused by a magnetic field effect, T2 red copper is used as the low-voltage side of the transformer, and local overheating of the magnetic field caused by an eddy current effect is rapidly led out by utilizing the small magnetic susceptibility and high heat conduction of the copper to reduce stray loss and ensure the service life of the transformer. However, due to the characteristics of the copper-steel dissimilar materials such as the physical properties thereof, the welding difficulty between the copper-steel dissimilar materials and the steel dissimilar materials is huge, and the interface fusion capability of a welded joint is poor and the mechanical property is low.

Disclosure of Invention

The invention aims to provide a self-protection flux-cored wire for welding T2 copper and 304 stainless steel, which solves the problems that the fusion property of a bonding interface is poor and welding cracks are easy to generate when the copper and the steel are welded at present.

The invention also aims to provide a preparation method of the self-shielded flux-cored wire for welding T2 copper and 304 stainless steel.

The technical scheme adopted by the invention is that the self-protection flux-cored wire for welding T2 copper and 304 stainless steel comprises a flux core and a welding skin, wherein the flux core consists of the following components in percentage by mass: nickel powder: 50% -60%, silicon powder: 2% -9%, titanium powder: 4% -8%, boron powder: 2% -4%, titanium dioxide: 1% -4%, rutile powder: 10% -13%, ferrosilicon powder: 1-2%, aluminum magnesium alloy powder: 2% -5%, cerium tetrafluoride: 1% -2%, calcium fluoride: 5% -9%, lithium carbonate: 1% -3%, zircon sand: 1 to 5 percent, and the sum of the mass percentages of the components is 100 percent.

The invention is also characterized in that:

the welding skin is a pure copper strip.

The filling rate of the flux-cored powder in the flux-cored wire is 22-28 wt.%.

The diameter of the flux-cored wire is 0.8mm-1.6 mm.

The invention adopts another technical scheme that the preparation method of the self-shielded flux-cored wire for welding the T2 copper and the 304 stainless steel comprises the following specific steps:

step 1: respectively weighing the medicine core powder according to the required mixture ratio by mass percent: nickel powder: 50% -60%, silicon powder: 2% -9%, titanium powder: 4% -8%, boron powder: 2% -4%, titanium dioxide: 1% -4%, rutile powder: 10% -13%, ferrosilicon powder: 1-2%, aluminum magnesium alloy powder: 2% -5%, cerium tetrafluoride: 1% -2%, calcium fluoride: 5% -9%, lithium carbonate: 1% -3%, zircon sand: 1-5 percent, the sum of the mass percentages of the components is 100 percent;

step 2: mixing the rutile powder, the titanium dioxide, the calcium fluoride, the lithium carbonate, the cerium tetrafluoride and the zircon sand weighed in the step 1 into mixed powder A, adding a certain amount of sodium water glass adhesive into the mixed powder A for fully kneading, uniformly mixing, fully sintering the mixed powder A in a heating furnace, and grinding after sintering to obtain mixed powder B;

and step 3: putting the nickel powder, the silicon powder, the titanium powder, the ferrosilicon powder, the aluminum-magnesium alloy powder and the boron powder weighed in the step 1 and the mixed powder B prepared in the step 2 into an automatic powder mixer for mixing to obtain flux-cored powder, wherein the powder mixing time is 20-24 hours, the obtained uniform flux-cored powder is placed into a vacuum ring furnace for heating to 250-350 ℃, and the temperature is kept for 2-7 hours for later use;

and 4, step 4: placing the pure copper strip with the burr side facing upwards at a strip placing turntable of a wire drawing machine, enabling the copper strip cleaned by alcohol to pass through a U-shaped roller, filling the flux core powder mixed in the step 3 into the formed U-shaped copper strip, sealing the U-shaped copper strip by a closed groove, and utilizing the apertureFinishing a first drawing process for a reducing die with the diameter of 2.5mm, standing the welding wire for 4 hours, releasing stress, and finally reducing the diameter of the flux-cored wire to 0.8-1.6 mm through the die in sequence;

and 5: and (4) straightening the flux-cored wire obtained in the step (4) by a wire winding machine, coiling the flux-cored wire into a disc, sealing and packaging the disc, and wiping oil stains on the surface of the flux-cored wire clean by using alcohol or acetone solution.

The invention is also characterized in that:

in the step 2, the sodium silicate adhesive is 22-25% of the total mass of the mixed powder A.

In the step 2, the sintering temperature is 600-750 ℃, the sintering time is 4-5 hours, and the granularity of the mixed powder B is 80-100 meshes.

In the step 4, the filling rate of the flux-cored powder in the flux-cored wire is 22-28 wt.%.

The invention has the beneficial effects that:

(1) the self-protection flux-cored wire does not need to use an external protection gas source device during welding, and slag and gas are generated by using a mineral slag system in the flux core to protect a molten pool, so that the welding device is light in weight and convenient to operate.

(2) The self-protection flux-cored wire is suitable for welding large-scale outdoor structural members, has strong wind resistance and air hole resistance, can be used for welding under four-level wind power, does not need to take any protection measures in the welding process, does not need to add protective gas in the welding process, and greatly improves the performance of a welding joint.

(3) The transition elements added in the self-protection flux-cored wire are suitable for welding dissimilar materials of T2 copper and 304 stainless steel, the transition between the welded weld metal and the base metals on two sides is stable, the interface bonding capability is obviously improved, and the strength and the toughness of a welding joint are greatly improved.

(4) Compared with a solid welding wire, the self-protection flux-cored welding wire has the advantages that molten drops are in spray transition, welding spatter is small, smoke dust is less, and welding seam formability is good.

(5) The self-protection flux-cored wire disclosed by the invention is simple in preparation method, has excellent all-position welding process performance, can be suitable for automatic welding equipment, is high in production efficiency, and can be used for large-scale batch production.

Drawings

FIG. 1 is a macro topography of T2 copper and 304 stainless steel welded test plates after welding in example 3 of the present invention;

FIG. 2 is a micro-topographical view of a copper-weld of a weld joint according to example 3 of the present invention;

FIG. 3 is a micro-topographical view of a steel-weld joint of a weld joint according to example 3 of the present invention.

Detailed Description

The present invention will be described in detail with reference to the following embodiments.

The invention provides a self-protection flux-cored wire for welding T2 copper and 304 stainless steel, which comprises a flux core and a welding skin, wherein the flux core consists of the following components in percentage by mass: nickel powder: 50% -60%, silicon powder: 2% -9%, titanium powder: 4% -8%, boron powder: 2% -4%, titanium dioxide: 1% -4%, rutile powder: 10% -13%, ferrosilicon powder: 1-2%, aluminum magnesium alloy powder: 2% -5%, cerium tetrafluoride: 1% -2%, calcium fluoride: 5% -9%, lithium carbonate: 1% -3%, zircon sand: 1 to 5 percent, and the sum of the mass percentages of the components is 100 percent.

The welding skin is a pure copper strip.

The filling rate of the flux-cored powder in the flux-cored wire is 22-28 wt.%.

The diameter of the flux-cored wire is 0.8mm-1.6 mm.

The invention also provides a preparation method of the self-protection flux-cored wire for welding the T2 copper and the 304 stainless steel, which comprises the following specific steps:

step 1: respectively weighing the medicine core powder according to the required mixture ratio by mass percent: nickel powder: 50% -60%, silicon powder: 2% -9%, titanium powder: 4% -8%, boron powder: 2% -4%, titanium dioxide: 1% -4%, rutile powder: 10% -13%, ferrosilicon powder: 1-2%, aluminum magnesium alloy powder: 2% -5%, cerium tetrafluoride: 1% -2%, calcium fluoride: 5% -9%, lithium carbonate: 1% -3%, zircon sand: 1-5 percent, the sum of the mass percentages of the components is 100 percent;

step 2: mixing the rutile powder, the titanium dioxide, the calcium fluoride, the lithium carbonate, the cerium tetrafluoride and the zircon sand weighed in the step 1 into mixed powder A, adding a certain amount of sodium water glass adhesive into the mixed powder A for fully kneading, uniformly mixing, fully sintering the mixed powder A in a heating furnace, and grinding after sintering to obtain mixed powder B;

wherein, the sodium silicate adhesive accounts for 22 to 25 percent of the total mass of the mixed powder A;

the sintering temperature is 600-750 ℃, the sintering time is 4-5 hours, and the granularity of the mixed powder B is 80-100 meshes;

and step 3: putting the nickel powder, the silicon powder, the titanium powder, the ferrosilicon powder, the aluminum-magnesium alloy powder and the boron powder weighed in the step 1 and the mixed powder B prepared in the step 2 into an automatic powder mixer for mixing to obtain flux-cored powder, wherein the powder mixing time is 20-24 hours, the obtained uniform flux-cored powder is placed into a vacuum ring furnace for heating to 250-350 ℃, and the temperature is kept for 2-7 hours for later use;

and 4, step 4: placing the pure copper strip with the burr side facing upwards at a strip placing turntable of a wire drawing machine, enabling the copper strip cleaned by alcohol to pass through a U-shaped roller, filling the flux core powder mixed in the step 3 into the formed U-shaped copper strip, sealing the U-shaped copper strip by a closed groove, and utilizing the apertureFinishing a first drawing process for a reducing die with the diameter of 2.5mm, standing the welding wire for 4 hours, releasing stress, and finally reducing the diameter of the flux-cored wire to 0.8-1.6 mm through the die in sequence;

wherein the filling rate of the flux-cored powder in the flux-cored wire is 22-28 wt.%;

and 5: and (4) straightening the flux-cored wire obtained in the step (4) by a wire winding machine, coiling the flux-cored wire into a disc, sealing and packaging the disc, and wiping oil stains on the surface of the flux-cored wire clean by using alcohol or acetone solution.

The function and function of each component in the welding wire are as follows:

(1) the nickel element is used as the main component in the flux core, because Ni and Cu and Fe elements can form an infinite solid solution, and no intermetallic compound is generated. Meanwhile, the Ni element can also reduce the austenite transformation temperature, is beneficial to the formation of acicular ferrite and improves the toughness of the welding seam.

(2) The silicon element can purify welding seams, deoxidize harmful impurities such as phosphorus, sulfur and the like, prevent the oxidation of the welding seams and stabilize a matrix to ensure the strength of the welding seams.

(3) The titanium element is a deoxidizing element and can be combined with the nitrogen element to form a TiN compound, thereby reducing the nitrogen pore capacity generated by the welding line, improving the strength and hardness value of the welding line and refining the welding line structure.

(4) Boron is generally used as a deoxidizer, residual boron can refine grains, and boron oxide is an excellent covering agent during smelting of copper alloy and can prevent welding metal from being oxidized.

(5) The titanium dioxide is used as a better gas making and slag making material, has the melting point of about 1560 ℃, can stabilize the arc, meets the requirement of a self-protection flux-cored wire welding environment, can be bonded with iron oxide to form titanate, and is convenient to remove slag.

(6) The ferrosilicon powder has the function of cleaning the welding seam and can remove redundant harmful elements such as S, P and the like in the welding seam.

(7) The rutile powder has the function of arc stabilization, can also improve the fluidity and the spreadability of weld metal, reduce the occurrence of pores in a weld, and adjust the alkalinity of slag, thereby improving the formability of the weld.

(8) The aluminum magnesium alloy powder is a deoxidizing agent and a denitrifying agent which are commonly used in a self-protection flux-cored wire, and is easy to combine with oxygen elements in a molten pool during welding to protect other elements in a welding line from loss.

(9) The calcium fluoride has the function of slagging, slag is easy to generate during welding, the calcium fluoride has the function of protecting a molten pool, and the viscosity and the alkalinity of the slag can be adjusted.

(10) The cerium tetrafluoride can purify grain boundaries, refine crystal grains, eliminate crystal cracks in welding seams and improve the strength and toughness of welding joints.

(11) The lithium carbonate has a gas-making effect, is easily decomposed into carbon dioxide gas during welding, protects a molten pool, and can inhibit the generation of nitrogen holes.

(12) The zircon sand is melted in a welding seam and can be decomposed into two crystal structures, one is monoclinic crystal, the other is stable tetragonal crystal, the volume is reduced by about 7% when the crystal is converted, and the change can be utilized to improve the slag removal performance of the welding flux and is beneficial to slag removal.