CN-122007828-A - Welding process for parts of water storage tank of liquid cooling system

Abstract

The invention discloses a welding process for parts of a water storage tank of a liquid cooling system, which is characterized in that suspension is needed during welding, the suspension is prepared from deionized water, citric acid monohydrate, nitric acid, hydrofluoric acid, precipitated barium sulfate micro powder, magnesium fluoride micro powder and composite corrosion inhibition dispersion premix liquid, the welding process comprises the steps of welding the parts of the water storage tank in a spliced mode, performing electrolytic polishing, filling argon gas for sealing welding, injecting the suspension and a stainless steel grinding needle into a cavity for performing alternating magnetic polishing, discharging waste liquid, and performing high-pressure flushing and neutralization. The invention maintains a high viscosity state in a static non-working area to shield and protect the parent metal by constructing a fluid physical network with yield stress, and drives a grinding needle to generate mechanical shearing force in a closed welding area to enable the fluid to shear thin, release acid liquor in a targeted way to soften oxide skin, and complete physical stripping by combining with inorganic micro powder friction, thereby realizing the fixed point removal of blind area welding spots and the synchronous protection of the parent metal in the non-working area.

Inventors

• WU LEI
• LIU ZHANKUI
• LIU YE

Assignees

• 立德欧流体科技(苏州)有限公司

Dates

Publication Date

20260512

Application Date

20260408

Claims (10)

1. 1. The fluorine-resistant oxidation suspension for the liquid cooling system water storage tank is characterized by comprising, by mass, 49.5-60.5 parts of deionized water, 2.0-2.5 parts of citric acid monohydrate solid, 20.0-23.0 parts of 68% nitric acid, 4.0-5.0 parts of 40% hydrofluoric acid, 10.0-15.0 parts of precipitated barium sulfate micro powder, 2.0-3.0 parts of magnesium fluoride micro powder and 1.5-2.0 parts of composite corrosion inhibition dispersion premix.
2. 2. An anti-fluorine oxidation suspension for a liquid cooling system water storage tank according to claim 1, wherein the anti-fluorine oxidation suspension interacts with the composite corrosion inhibition dispersion premix in an acidic aqueous phase through the precipitated barium sulfate micropowder and the magnesium fluoride micropowder.
3. 3. The fluorine-resistant oxidation suspension for the liquid cooling system water storage tank according to claim 1 is characterized in that the composite corrosion inhibition dispersion premix is prepared from the following raw materials, by mass, 65.0-75.0 parts of deionized water, 10.0-15.0 parts of polyethylene glycol 40010.0 parts and 15.0-20.0 parts of hexamethylenetetramine solid.
4. 4. A welding process for parts of a liquid cooling system water tank, an anti-oxyfluoride suspension for a liquid cooling system water tank according to any one of claims 1 to 3, comprising the steps of: S1, splicing and welding a main shell (1), a side wall pipe fitting (2) and a first side end cover (3) of an austenitic stainless steel water storage tank, keeping a second side end cover (4) unwelded, keeping a cavity semi-open, injecting electrolytic polishing liquid for electrolytic polishing, cleaning and blow-drying; S2, filling high-purity argon into the inner cavity of the water storage tank for replacement, and performing laser closed welding on the reserved part under the protection of the argon; S3, adding deionized water, citric acid monohydrate solid, nitric acid, hydrofluoric acid, precipitated barium sulfate micro powder and magnesium fluoride micro powder into a reaction kettle, carrying out high-shear pulping, and then adding a composite corrosion inhibition dispersion premix solution to uniformly mix to prepare a suspension; s4, injecting the suspension into a closed water storage tank to immerse a closed weld joint, putting a stainless steel grinding needle into the closed water storage tank, and performing alternating magnetic polishing treatment after a micro-pressure one-way exhaust valve is arranged at a liquid injection pipe orifice; S5, discharging suspension waste liquid and a stainless steel grinding needle, performing high-pressure water washing and anhydrous sodium carbonate aqueous solution circulating neutralization washing on the inner cavity, and finally performing pure water rinsing and hot air drying.
5. 5. The welding process for the liquid cooling system water storage tank part according to claim 4, wherein the specific process parameters of S1 are that the electrolytic polishing liquid adopts phosphoric acid-sulfuric acid type electrolytic polishing liquid, the temperature is controlled to be 55-65 ℃, the direct current voltage is applied to be 10-15V, the current density is controlled to be 10-20A/dm 2 , and the electrolytic polishing time is 5-8 minutes.
6. 6. The welding process for the liquid cooling system water storage tank part according to claim 4, wherein the specific implementation mode of the step S2 is that high-purity argon with the purity of more than or equal to 99.999% is continuously filled into the liquid cooling system water storage tank part through a side wall pipe at the flow rate of 10-15L/min, and the liquid cooling system water storage tank part is continuously replaced for 3-5 minutes.
7. 7. The welding process for the liquid cooling system water storage tank part is characterized in that the specific preparation mode of S3 is that deionized water and citric acid monohydrate solid are added into a high-shear reaction kettle with a polytetrafluoroethylene lining and stirred until the solid is completely dissolved, nitric acid and hydrofluoric acid are slowly and sequentially added dropwise under the condition that the jacket circulating water cooling keeps the temperature to be 20-30 ℃, a high-shear dispersing machine is started, the rotating speed is set to 1500-2000 rpm, precipitated barium sulfate micro powder and magnesium fluoride micro powder are slowly added during stirring, high-shear beating is continued for 25-30 minutes, and the composite corrosion inhibition dispersion premix is added into the reaction kettle and stirred for 5 minutes and uniformly mixed at the rotating speed of 300rpm within 15-30 minutes before polishing operation is planned.
8. 8. The welding process for the liquid cooling system water storage tank part, which is characterized in that the concrete preparation method of the composite corrosion inhibition dispersion premix is that deionized water and polyethylene glycol 400 are added into a reaction kettle at normal temperature to be uniformly mixed, hexamethylenetetramine solid is slowly added, mechanical stirring is started, the rotating speed is set to 300-500 rpm, the temperature is slowly increased to 40-45 ℃ and the temperature is constant, the stirring is carried out for 40-50 minutes, and the transparent viscous composite corrosion inhibition dispersion premix is obtained after cooling to room temperature.
9. 9. The welding process for the liquid cooling system water storage tank part, which is disclosed by claim 4, is characterized in that the specific implementation parameters of S4 are that the adding amount of a stainless steel grinding needle is 5% -8% of the inner cavity volume of the water storage tank, the opening and closing pressure difference of the micro-pressure one-way exhaust valve is set to be 0.01-0.03 MPa, the rotating speed of an alternating magnetic field is set to be 1500-2500 rpm, and the welding process is operated for 1-8 minutes at the ambient temperature of 20-35 ℃.
10. 10. The welding process for the liquid cooling system water storage tank part is characterized in that the specific flushing process of S5 is characterized in that a tubular high-pressure spray nozzle is used for extending into a water storage tank, high-pressure deionized water with the pressure of 0.3-0.5 MPa is used for flushing an inner cavity for 2-3 minutes, anhydrous sodium carbonate aqueous solution with the mass concentration of 2.0% -3.0% is pumped for circulating flushing for 3 minutes, and finally hot air with the temperature of 60-80 ℃ is introduced for blow drying.

Description

Welding process for parts of water storage tank of liquid cooling system Technical Field The invention relates to the technical field of liquid cooling system manufacturing and surface treatment, in particular to a welding process for parts of a liquid cooling system water storage tank. Background The austenitic stainless steel water storage tank in the liquid cooling system is usually required to be assembled by welding in the manufacturing process, under the action of welding high temperature, a layer of compact metal oxide skin, namely welding spots, is generated on the surface of a welding seam and a heat affected zone of the welding seam, the welding spots mainly consist of oxides of iron and chromium, if the welding spots are not completely removed, local pitting corrosion is easily caused in the subsequent operation of equipment, the leakage of cooling liquid is further caused, the service life of the system is seriously influenced, and in order to ensure the surface smoothness and corrosion resistance of the inner cavity of the water storage tank, the inner wall is generally treated by adopting technologies such as pickling passivation or electrolytic polishing in industrial production. Along with the development of the design of the water storage tank to compactness and complexity, after the final sealing welding is finished, a closed blind area which is difficult to directly touch is formed in a plurality of cavities, and because the tank is in a sealing or semi-sealing state at the moment, the conventional surface treatment process faces extremely great limitation, the conventional free pickling solution flows in the cavities in an uncontrolled manner, so that the local welding spots cannot be cleaned at high concentration and fixed points, strong acid can be contacted in a large area to damage the bright parent metal of a non-working area which is subjected to the early polishing treatment, serious excessive corrosion is caused, the whole surface is roughened, and in addition, the conventional mechanical grinding means are limited by the macroscopic size and the force application angle of a tool, so that the narrow blind angle and the blind area in the tank cannot be cut and stripped effectively. In order to overcome the space obstacle of a closed cavity, the industry tries to introduce a magnetic polishing technology to match with an acid grinding liquid for internal operation, however, the existing fluid lacks effective control on the rheological state, if a conventional low-viscosity pickling liquid is directly adopted, a strong corrosive medium can still diffuse in the whole cavity to cause indiscriminate corrosion, if the conventional thickener is added to limit the flow of the acid liquid, the conventional powder is extremely easy to generate severe chemical reaction in the strong oxidation mixed acid containing hydrofluoric acid, the serious pressure-holding problem is rapidly caused by a large amount of heat release and gas production behaviors in the cavity of the closed water storage tank, the extremely high container fracture risk exists, meanwhile, the conventional organic corrosion inhibitor can rapidly generate oxidative degradation in the strong oxidizing concentrated nitric acid environment, and effective cutting stripping is difficult to be conducted deep into dead corners of the internal dead zones. Disclosure of Invention Aiming at the defects of the prior art, the invention provides a welding process for parts of a liquid cooling system water storage tank, which solves the problems that single mechanical polishing is difficult to penetrate into dead corners of internal dead zones for effective cutting and stripping and cleaning dead corners and potential safety hazards exist. The fluorine-resistant oxidation suspension for the liquid cooling system water storage tank comprises, by mass, 49.5-60.5 parts of deionized water, 2.0-2.5 parts of citric acid monohydrate solid, 20.0-23.0 parts of 68% nitric acid, 4.0-5.0 parts of 40% hydrofluoric acid, 10.0-15.0 parts of precipitated barium sulfate micro powder, 2.0-3.0 parts of magnesium fluoride micro powder and 1.5-2.0 parts of composite corrosion inhibition dispersion premix. By adopting the technical scheme, as the precipitated barium sulfate micro powder and magnesium fluoride micro powder are adopted to interact with the composite corrosion inhibition dispersion premix liquid in the acidic aqueous phase, a mechanochemical cooperative linkage mechanism is established between conventional pickling and mechanical polishing, so that the effects of precisely removing blind area welding spots and protecting polishing base materials in a non-working area are obtained; the precipitated barium sulfate and magnesium fluoride in a thermodynamic stable state are introduced into mixed acid, inorganic powder bridges with a high molecular chain segment in the composite corrosion inhibition dispersion premix liquid in a water phase through int