Steel polishing and phosphating integrated electrolyte and preparation method and application thereof

Abstract

The invention discloses a steel polishing and phosphating integrated electrolyte and a preparation method and application thereof, and belongs to the technical field of phosphating. The steel polishing and phosphating integrated electrolyte comprises the following raw materials in percentage by weight: 30-40% of phosphoric acid, 15-25% of zinc oxide, 10-20% of organic acid, 4-8% of fatty alcohol, 2-4% of inorganic ammonium salt, 0.4-1% of a polarization agent, 0.2-0.6% of a dispersing agent and the balance of deionized water. According to the method, the steel polishing and phosphating integrated electrolyte serves as an electrolyte, the steel material is subjected to electrolytic polishing treatment and electrolytic phosphating treatment, and a steel material finished product subjected to electrolytic polishing and electrolytic phosphating is obtained. The steel polishing and phosphating integrated electrolyte disclosed by the invention supports electrolytic polishing and electrolytic phosphating at the same time, and has excellent phosphating effect and polishing effect; according to the steel polishing and phosphating integrated process, the resource utilization efficiency is greatly improved based on polarity switching, and the production cost is reduced.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of phosphating, and particularly relates to a steel polishing and phosphating integrated electrolyte as well as a preparation method and application thereof. BACKGROUND

[0002] Although the traditional immersion phosphating process performs excellently in the field of metal corrosion prevention, it has significant defects. The bath solution contains harmful substances such as chromate and nitrite, and heavy metal ions such as zinc, nickel and manganese. The treatment temperature is high, and it needs to be operated at 80 DEG C. A large amount of waste slag containing heavy metals and phosphorus is generated, and the disposal cost of hazardous waste is high. CN106756926A discloses an environmentally friendly immersion phosphating solution. By using zinc salt and manganese salt as main salt, combined with corrosion inhibitors such as citric acid and sodium tripolyphosphate, low-temperature phosphating is realized at 50-75 DEG C. Although the use of chromate and nitrite is avoided, heating is still required and heavy metal ions such as zinc and manganese are still needed. In addition, hazardous waste such as phosphating slag is also generated.

[0003] In contrast, electrolytic phosphating generates a dense phosphating film through cathodic reduction reaction and does not produce phosphating slag. CN118497864A discloses a room temperature ultrasonic electrolytic phosphating solution formula. Through the synergistic effect of phosphoric acid, zinc oxide, nitrate and chelating agent, efficient phosphating without heating is realized under ultrasonic assistance, which significantly reduces energy consumption and eliminates waste slag discharge.

[0004] Traditional chemical polishing relies on the chemical corrosion effect of strong acid (such as sulfuric acid and phosphoric acid), and has problems such as violent reaction, poor surface uniformity, easy generation of acid mist and heavy metal-containing waste liquid. In contrast, electrolytic polishing can achieve better surface flattening effect by selectively dissolving micro convexities through anodic oxidation, and has high polishing treatment efficiency and does not produce volatile acid mist pollution.

[0005] However, although electrolytic phosphating and electrolytic polishing technology partially solve the environmental problems of traditional processes, they still have systematic defects. Electrolytic phosphating generates a dense phosphating film through cathodic reduction reaction, which avoids the generation of phosphating slag, but requires continuous replenishment of metal cations such as zinc and iron and phosphate ions in long-term operation. At the same time, the accumulation of free acid can easily lead to the failure of the bath solution, which requires frequent testing and adjustment of the phosphating solution, consuming a large amount of labor cost. Electrolytic polishing achieves higher flattening by anodic oxidation, but due to the enrichment of metal cations and the consumption of free acid, the application effect of the polishing solution will gradually degrade and eventually fail, and the polishing solution must be replaced regularly, and waste liquid and waste slag containing heavy metals are discharged, which has high disposal cost and great pollution risk.

[0006] More importantly, in the current actual production process, electrolytic phosphating and electrolytic polishing are operated as independent processes in separate tanks, resulting in low resource recycling rate. Electrolytic phosphating consumes metal ions and phosphate and produces free acid, while electrolytic polishing consumes free acid and releases metal ions, and the by-products of the two processes cannot be utilized mutually. This fragmented process not only increases the investment in electrolysis and supporting equipment, but also causes waste of chemical resources, and increases the disposal cost and environmental pressure of hazardous waste.

[0007] Therefore, it is of great significance to provide an electrolyte with excellent phosphating effect and polishing effect and a polishing-phosphating integrated process. SUMMARY

[0008] In order to overcome the deficiencies of the prior art, the present application provides a steel polishing-phosphating integrated electrolyte, a preparation method and application thereof. The steel polishing-phosphating integrated electrolyte of the present application has excellent phosphating effect and polishing effect, and can realize integrated polishing-phosphating treatment of steel through a simple polarity switching process.

[0009] The technical scheme adopted by the present application to solve the technical problems is:

[0010] The present application provides a steel polishing-phosphating integrated electrolyte, which comprises the following raw materials in percentage by weight:

[0011] Phosphoric acid 30-40%, zinc oxide 15-25%, organic acid 10-20%, fatty alcohol 4-8%, inorganic ammonium salt 2-4%, polarizing agent 0.4-1%, dispersing agent 0.2-0.6%, and the balance being deionized water.

[0012] Preferably, the organic acid is one or more of oxalic acid, citric acid, malic acid, tartaric acid, succinic acid, hydroxyethylidene diphosphonic acid, sodium hydroxyethylidene diphosphonate, potassium hydroxyethylidene diphosphonate, amino-tris-methylene phosphonic acid, ethylenediamine tetra-methylene phosphonic acid, and penta-sodium ethylenediamine tetra-methylene phosphonate.

[0013] Preferably, the fatty alcohol is one or more of ethanol, glycerol, and hexanediol.

[0014] Preferably, the inorganic ammonium salt is one or more of ammonium sulfate, ammonium ferrous sulfate, ammonium zinc sulfate, and triammonium phosphate.

[0015] Preferably, the polarizing agent is one or more of benzalacetone, o-chlorobenzaldehyde, vanillin, and anisic aldehyde.

[0016] Preferably, the dispersing agent is one or more of nonylphenol polyoxyethylene ether, sodium lauryl alcohol polyether sulfate, sodium lauryl polyoxyethylene ether sulfate, sodium dodecyl benzene sulfonate, and potassium dodecyl benzene sulfonate.

[0017] Preferably, the steel polishing phosphating integrated electrolyte comprises the following raw materials in percentage by weight:

[0018] Phosphoric acid 35%, zinc oxide 20%, citric acid 10%, tartaric acid 5%, ethanol 6%, ferrous ammonium sulfate 3%, benzalacetone 0.7%, nonylphenol polyoxyethylene ether 0.3%, sodium lauryl polyether sulfate 0.1%, and the balance is deionized water.

[0019] The present application provides a preparation method of the above-mentioned steel polishing phosphating integrated electrolyte, comprising the following steps:

[0020] (1) Add phosphoric acid and zinc oxide to deionized water, heat up while keeping stirring until the zinc oxide is completely reacted to obtain a mixed solution;

[0021] (2) Cool down the mixed solution obtained in step (1), and then add organic acid, dispersant and polarizer successively, continue stirring until all the added raw materials are completely dissolved;

[0022] (3) Continue to cool down the mixed solution obtained in step (2), then add fatty alcohol, stir uniformly, and then add inorganic ammonium salt, continue to stir until completely dissolved, and continue to stir to obtain the steel polishing phosphating integrated electrolyte.

[0023] Preferably, the temperature in step (1) is heated to 60-70℃;

[0024] Preferably, the temperature in step (2) is cooled to 40-50℃;

[0025] Preferably, the temperature in step (3) is continuously cooled to 10-20℃.

[0026] Preferably, step (1) is specifically: first add phosphoric acid in deionized water, control the stirring speed at 100-120r / min, then add zinc oxide in 3-5 batches with an interval of 1-2 minutes, heat to 60-70℃, and adjust the stirring speed to 160-200r / min until the zinc oxide is completely reacted;

[0027] Preferably, step (2) is specifically: cool down the mixed solution obtained in step (1) to 40-50℃ naturally, add organic acid with a stirring speed of 120-140r / min, and then add dispersant and polarizer successively after completely dissolved, keep the stirring speed consistent until all the raw materials are completely dissolved;

[0028] Preferably, step (3) is specifically: continue to cool down the mixed solution obtained in step (2) to 10-20℃, add fatty alcohol with a stirring speed of 100-120r / min, and then add inorganic ammonium salt after completely dissolved, keep the stirring speed consistent until completely dissolved, and continue to stir for 30-60 minutes.

[0029] The present application provides a steel polishing and phosphating integrated process, comprising the following steps:

[0030] The steel polishing and phosphating integrated electrolyte is used as an electrolyte to perform electrolytic polishing and electrolytic phosphating on the steel material, so as to obtain a finished steel material after electrolytic polishing and electrolytic phosphating.

[0031] Preferably, the electrolyte used for electrolytic phosphating is the electrolyte after electrolytic polishing.

[0032] Preferably, the steel polishing and phosphating integrated process specifically comprises the following steps:

[0033] S201. The steel polishing and phosphating integrated electrolyte is injected into an electrolytic tank, heated, stirred, and a circulating pump is started;

[0034] S202. A cathode plate is installed in the electrolytic tank and connected to a negative electrode of an electrolytic power supply, and a conductive pressure roller is connected to a positive electrode of the electrolytic power supply;

[0035] S203. Raw steel material is sequentially connected to a straightening machine, a sand belt machine, the conductive pressure roller, a water washing tank, the electrolytic tank, a post water washing tank, a hot air drying machine, and an inverted take-up machine;

[0036] S204. The current density, polishing temperature, and wire speed are set, the electrolytic power supply and the inverted take-up are started, and the raw steel material is subjected to electrolytic polishing to obtain polished steel material after electrolytic polishing;

[0037] S205. The tank heating is stopped, the process polarity is switched, and the electrolytic plate is replaced. An anode plate is installed in the electrolytic tank and connected to the positive electrode of the electrolytic power supply, and the conductive pressure roller is connected to the negative electrode of the electrolytic power supply;

[0038] S206. The polished steel material after electrolytic polishing is sequentially connected to the straightening machine, the conductive pressure roller, the water washing tank, the electrolytic tank, the post water washing tank, the hot air drying machine, and the inverted take-up machine;

[0039] S207. The current density, phosphating temperature, and wire speed are set, the electrolytic power supply and the inverted take-up are started, and the polished steel material is subjected to electrolytic phosphating to obtain finished steel material after electrolytic polishing and electrolytic phosphating.

[0040] Preferably, in step S201, the heating temperature is 30-50°C, and the stirring speed is maintained at 150-250 r / min.

[0041] Preferably, in step S204, the current density for electrolytic polishing is 10-30 A / dm 2 , the polishing temperature for electrolytic polishing is maintained at 30-50°C, and the wire speed is maintained at 0.2-0.4 m / s.

[0042] Preferably, in step S207, the current density of the electrolytic phosphating is 20-40 A / dm 2 The phosphating temperature of the electrolytic phosphating is kept at 10-20 DEG C, and the wire speed is kept at 0.8-1.2 m / s.

[0043] The application provides a steel material finished product after electrolytic polishing and electrolytic phosphating, which is prepared by the above-mentioned steel polishing and phosphating integrated process.

[0044] The application has the following beneficial effects:

[0045] (1) The integrated electrolyte of the application supports electrolytic polishing and electrolytic phosphating simultaneously:

[0046] The electrolytic polishing / phosphating integrated electrolyte of the application can realize micro-leveling of the metal surface through anodic oxidation, has excellent electrolytic polishing effect, and can form a dense phosphating film under cathodic reduction conditions, and has excellent electrolytic phosphating effect.

[0047] (2) The polarity switching integrated process of the application integrates two processes and improves resource utilization:

[0048] The application combines the traditional independent electrolytic polishing and electrolytic phosphating processes into a single tank, and through switching the electrode polarity, the anodic polishing and cathodic phosphating modes can be cyclically operated in the same tank. The integrated design of the process reduces the equipment cost, and the single-tank heating also reduces the energy consumption.

[0049] (3) The polarity switching integrated process of the application reduces heavy metal waste residue and waste liquid, and reduces the disposal cost of hazardous waste:

[0050] The application realizes mutual utilization of electrolytic polishing / phosphating byproducts, directly supplements the film-forming elements required for the phosphating reaction by using the metal ions generated by electrolytic polishing, consumes the free acid accumulated by electrolytic phosphating by using the electrolytic polishing process, improves the stability of the tank liquid, and reduces the generation of heavy metal waste liquid and waste residue in the traditional process. BRIEF DESCRIPTION OF DRAWINGS

[0051] Figure 1 The metallographic microscope photo of the phosphating film layer prepared in Example 3.

[0052] Figure 2 The metallographic microscope photo of the phosphating film layer prepared in Comparative Example 1.

[0053] Figure 3 The metallographic microscope photo of the phosphating film layer prepared in Comparative Example 2.

[0054] Figure 4The metallographic microscope photo of the phosphating film layer prepared for the comparative example 3.

[0055] Figure 5 The metallographic microscope photo of the phosphating film layer prepared for the comparative example 4.

[0056] Figure 6 The metallographic microscope photo of the phosphating film layer prepared for the comparative example 5.

[0057] Figure 7 The metallographic microscope photo of the phosphating film layer prepared for the comparative example 6. DETAILED DESCRIPTION

[0058] The application will be further described below in conjunction with the drawings and examples.

[0059] The concept, specific scheme and technical effects of the present application will be described clearly and completely in conjunction with the examples and drawings, so as to fully understand the purpose, features and effects of the present application. Obviously, the described examples are only a part of the examples of the present application, but not all the examples. Based on the examples of the present application, other examples obtained by those skilled in the art without creative labor are within the protection scope of the present application. Each technical feature in the present application can be combined with each other on the premise of no contradiction and conflict.

[0060] The present application provides a steel polishing and phosphating integrated electrolyte, a preparation method and a polarity switching integrated process.

[0061] In a first aspect, the present application provides a steel polishing and phosphating integrated electrolyte, which comprises the following raw materials in percentage by weight:

[0062] phosphoric acid 30-40%, zinc oxide 15-25%, organic acid 10-20%, fatty alcohol 4-8%, inorganic ammonium salt 2-4%, polarizing agent 0.4-1%, dispersing agent 0.2-0.6%, and the balance is deionized water;

[0063] In some examples, the organic acid is any one or any combination of oxalic acid (CAS# 144-62-7), citric acid (CAS# 77-92-9), malic acid (CAS# 6915-15-7), tartaric acid (CAS# 87-69-4), succinic acid (CAS# 110-15-6), hydroxyethylidene diphosphonic acid (CAS# 2809-21-4), sodium hydroxyethylidene diphosphonate (CAS# 29329-71-3), potassium hydroxyethylidene diphosphonate (CAS# 67953-76-8), amino-tris-methylene phosphonic acid (CAS# 6419-19-8), ethylenediamine tetra-methylene phosphonic acid (CAS# 1429-50-1), and ethylenediamine tetra-methylene phosphonic acid pentasodium (CAS# 7651-99-2).

[0064] In some embodiments, the fatty alcohol is any one or more of ethanol (CAS# 64-17-5), glycerol (CAS# 56-81-5), hexanediol (CAS# 107-41-5).

[0065] In some embodiments, the inorganic ammonium salt is any one or more of ammonium sulfate (CAS# 7783-20-2), ferrous ammonium sulfate (CAS# 10045-89-3), zinc ammonium sulfate (CAS# 77998-33-5), triammonium phosphate (CAS# 10124-31-9).

[0066] In some embodiments, the polarizing agent is any one or more of benzalacetone (CAS# 1896-62-4), o-chlorobenzaldehyde (CAS# 89-98-5), vanillin (CAS# 121-33-5), anisaldehyde (CAS# 123-11-5).

[0067] In some embodiments, the dispersing agent is any one or more of nonylphenol polyoxyethylene ether (CAS# 127087-87-0), sodium lauryl polyoxyethylene ether sulfate (CAS# 9004-82-4), sodium lauryl polyoxyethylene ether sulfate (CAS# 68585-34-2), sodium dodecylbenzenesulfonate (CAS# 69669-44-9), potassium dodecylbenzenesulfonate (CAS# 27177-77-1).

[0068] In the present invention, the phosphoric acid is added to the electrolyte, providing acid radical ions during electrolytic phosphating, which can combine with metal cations to deposit on the surface of the metal substrate and transform into insoluble phosphate protective film. During electrolytic polishing, the phosphoric acid with certain viscosity will form a liquid film diffusion layer on the surface of the metal substrate, promoting the preferential dissolution of the micro-protrusions on the anode surface, improving the roughness of the metal surface and increasing the flatness.

[0069] In the present invention, the zinc oxide is added to the electrolyte, providing the metal cations required for the electrolytic phosphating film layer during electrolytic phosphating.

[0070] In the present application, the organic acid is added to the electrolyte, which can effectively buffer the free acid in the phosphating solution during electrolytic phosphating, and realize the steady-state regulation of the electrolytic phosphating tank solution acidity. The acidity control is a key factor affecting the uniformity and quality of the phosphating film. Through the combination of various organic acids, the microstructure of the electrolytic phosphating film can be optimized, the electrolytic phosphating effect can be enhanced, the porosity and crack phenomenon can be reduced, and the appearance quality of the electrolytic phosphating film can be improved. During electrolytic polishing, the organic acid can form a stable complex with metal ions, effectively chelate the metal cations in the polishing solution, promote the dissolution of the metal substrate and impurity particles, realize the steady-state regulation of the electrolytic polishing solution metal ions, and improve the polishing efficiency.

[0071] In the present application, the fatty alcohol is added to the electrolyte, which can promote the dissolution and dispersion of the effective components in the electrolyte. During electrolytic phosphating, it can reduce the surface tension, enhance the wettability, promote the detachment of bubbles from the substrate surface, expose more active sites for electrolytic phosphating, and improve the phosphating efficiency. During electrolytic polishing, it can relieve chemical corrosion, form a liquid film diffusion layer with phosphoric acid, promote uniform contact between the polishing solution and the metal substrate surface, avoid local polishing unevenness, and improve polishing flatness.

[0072] In the present application, the inorganic ammonium salt is added to the electrolyte, which can increase the ion concentration of the solution, reduce the resistance of the electrolyte, and accelerate the movement rate of electrons, thereby greatly improving the conductivity of the electrolyte, improving the current efficiency of the electrochemical reaction process, promoting the electrochemical reaction, significantly reducing the voltage required for electrolytic polishing, shortening the electrochemical reaction time, improving the efficiency of electrolytic phosphating and polishing, and reducing energy consumption.

[0073] In the present application, the polarizer is added to the electrolyte, which can be preferentially adsorbed or electrochemically reduced at the location where the metal crystal grows faster, increase the cathode overpotential, block the discharge of metal cations, and strengthen the hydrogen evolution reaction. During electrolytic phosphating, it promotes the deposition of phosphate on the metal wire, inhibits the reduction reaction of metal ions on the cathode plate, and improves the directionality and compactness of phosphate deposition.

[0074] In the present application, the dispersant is added to the electrolyte, which can promote the dissolution and dispersion of the effective components in the electrolyte, reduce the surface tension of the electrolyte, and improve the wettability and coverage of the electrolyte on the metal substrate surface.

[0075] In a second aspect, the present application provides a preparation method of a steel polishing and phosphating integrated electrolyte.

[0076] S101. Prepare the raw materials according to the weight of each liter of phosphating solution;

[0077] S102. Slowly add prepared phosphoric acid and zinc oxide into deionized water, gradually heat up while maintaining sufficient stirring until zinc oxide is completely reacted to form a uniform mixture.

[0078] S103. Stop heating and allow the mixture to cool naturally. When the temperature drops to an appropriate range, add organic acid, dispersant, and polarizer in sequence, continue to stir thoroughly to ensure complete dissolution of all added raw materials.

[0079] S104. Continue to cool the mixture to 10-20℃, then add fatty alcohol, stir until dissolved, then add inorganic ammonium salt, continue to stir until completely dissolved, and continue to stir for a period of time to obtain a uniform and stable steel wire polishing and phosphating integrated electrolyte.

[0080] In some embodiments, in step S102, first slowly add phosphoric acid into deionized water, control the stirring speed at 100-120r / min, then add zinc oxide in 3-5 batches with 1-2 minutes interval, heat to 60-70℃, adjust the stirring speed to 160-200r / min, until zinc oxide is completely reacted to ensure the completeness of the reaction and the uniformity of the mixture.

[0081] In some embodiments, in step S103, naturally cool to 40-50℃, add organic acid, stirring speed 120-140r / min, after complete dissolution, add dispersant and polarizer in sequence, keep the stirring speed consistent until all raw materials are completely dissolved to ensure the stability and uniformity of the electrolyte.

[0082] In some embodiments, in step S104, continue to cool to 10-20℃, add fatty alcohol, stirring speed 100-120r / min, after complete dissolution, add inorganic ammonium salt, keep the stirring speed consistent until completely dissolved, then continue to stir for 30-60 minutes to obtain a uniform and stable electrolyte.

[0083] In the present application, the role of step S102 is to promote the complete reaction of phosphoric acid and zinc oxide by controlling the feeding sequence and stirring conditions, to generate a uniform mixture. By adding the materials step by step and gradually heating, the complete reaction of phosphoric acid and zinc oxide is ensured, avoiding local overheating or uneven reaction caused by violent reaction, thereby improving the quality and uniformity of the mixture.

[0084] In the present application, the role of step S103 is to ensure uniform dispersion and complete dissolution of each component by gradually adding functional raw materials, and to ensure sufficient dissolution of functional raw materials under appropriate conditions by controlling temperature and stirring speed, forming a uniform and stable electrolyte, avoiding separation of effective components.

[0085] In the present application, the role of step S104 is to add volatile or heat-sensitive raw materials under low temperature conditions to avoid the influence of high temperature on heat-sensitive raw materials, and at the same time, to further homogenize and stabilize the electrolyte system by continuing to stir, so as to finally obtain a uniform and stable steel wire polishing-phosphating integrated electrolyte.

[0086] In a third aspect, the present application provides a steel polishing-phosphating integrated process.

[0087] S201. Inject the steel polishing-phosphating integrated electrolyte into the electrolytic tank, heat, stir, and start the circulating pump;

[0088] S202. Install the cathode plate in the electrolytic tank and connect it to the negative electrode of the electrolysis power supply, and connect the conductive pressure roller to the positive electrode of the electrolysis power supply;

[0089] S203. Connect the raw material wire coil (steel material) to the straightening machine, sand belt machine, conductive pressure roller, water washing tank, electrolytic tank, post-water washing tank, hot air dryer, and inverted wire collector in sequence;

[0090] S204. Set the current density, polishing temperature, and wire running speed, start the electrolysis power supply and inverted wire collector, and perform electrolytic polishing treatment on the raw material wire to obtain polished wire after electrolytic polishing;

[0091] S205. Stop heating the tank body, switch the process polarity, replace the electrolytic plate, install the anode plate in the electrolytic tank and connect it to the positive electrode of the electrolysis power supply, and connect the conductive pressure roller to the negative electrode of the electrolysis power supply;

[0092] S206. Connect the polished wire coil to the straightening machine, conductive pressure roller, water washing tank, electrolytic tank, post-water washing tank, hot air dryer, and inverted wire collector in sequence;

[0093] S207. Set the current density, phosphating temperature, and wire running speed, start the electrolysis power supply and inverted wire collector, and perform electrolytic phosphating treatment on the polished wire to obtain finished wire after electrolytic polishing and electrolytic phosphating.

[0094] In some embodiments, in step S201, the heating temperature is 30-50℃, and the stirring speed is maintained at 150-250r / min to promote the uniform distribution of the electrolyte.

[0095] In some embodiments, in step S202, the cathode plate material is a hydrogen evolution plate such as a graphite plate, a titanium plate, a platinum plate, a stainless steel plate, etc., the cathode plate shape is sheet-shaped, plate-shaped, net-shaped or rod-shaped, and the cathode plate area should be more than 1.5 times the surface area of the metal substrate in the reaction zone. The electrolysis power supply must output a direct current power supply with a voltage / current stability of ≤1%, a ripple and noise of ≤1%, support for constant current / constant voltage mode switching, including overvoltage, undervoltage, overcurrent, short circuit, overheating, open phase protection, etc., according to the power and environment to match the corresponding cooling method, which can adapt to humid and corrosive environments, meet safety certification and industry standards, and ensure stable and controllable electrolysis process. The conductive pressure roller needs to have a high conductivity of ≥80% IACS, can withstand short-term arc impact, needs to resist corrosion of acidic media such as electrolyte, the roller hardness needs to match the material being pressed, the compressive strength is ≥500 MPa, can withstand high-frequency cyclic loads, and does not deform under long-term pressure.

[0096] In some embodiments, in step S203, the straightening machine needs to have sufficient straightening force to adapt to the straightening needs of metal substrates of different strengths, and can use a multi-roller design to ensure that the straightness of the wire is ≤2 mm / m. The belt sander can adapt to 60#-200# mesh sanding belts, and the abrasive on the surface of the sanding belt is silicon carbide or aluminum oxide to remove the oxide layer and impurities on the surface of the metal substrate. The water washing tank and the post-water washing tank have clean water, with a pH value of 6-8, a turbidity of ≤5 NTU, and a total dissolved solids content of ≤1000 mg / L; the hot air dryer temperature is controlled at 120°C-160°C to ensure uniform drying of the wire.

[0097] In some embodiments, in step S204, the current density of electrolytic polishing is 10-30 A / dm 2 , the electrolytic polishing temperature is maintained at 30°C-50°C, and the wire speed is maintained at 0.2-0.4 m / s to control the speed and quality of electrolytic polishing.

[0098] In some embodiments, in step S205, the anode plate material is graphite plate, platinum-coated plate, iridium-tantalum mixed metal oxide-coated plate, platinum-iridium-tantalum mixed metal oxide-coated plate, etc. Oxygen evolution plate, the shape of the anode plate is sheet, plate, net or rod, and the area of the anode plate should be more than 1.5 times the surface area of the metal substrate in the reaction zone. The electrolysis power supply must output direct current power, the voltage / current stability is ≤1%, the ripple and noise is ≤1%, it supports constant current / constant voltage mode switching, including overvoltage, undervoltage, overcurrent, short circuit, overheating, open phase protection, etc. According to the power and the environment, the corresponding cooling method is matched, which can adapt to humid and corrosive environment, meet the safety certification and industry standard, and ensure the stability and controllability of the electrolysis process. The conductive pressure roller needs to have high conductivity of ≥80% IACS, can withstand short-time arc impact, needs to resist the corrosion of acidic medium such as electrolyte, the roller hardness needs to match the pressed material, the compressive strength is ≥500MPa, can withstand high-frequency cyclic load and long-term pressure without deformation.

[0099] In some embodiments, in step S206, the straightening machine needs to have enough straightening force to adapt to the straightening needs of metal substrates of different strengths, and a multi-roller design can be used to ensure that the straightness of the wire is ≤2mm / m. The water quality of the water washing tank and the post-water washing tank is clean, the pH value is between 6-8, the turbidity is ≤5NTU, and the total dissolved solids content is ≤1000mg / L; the temperature of the hot air dryer is controlled at 120℃-160℃ to ensure uniform drying of the wire.

[0100] In some embodiments, in step S207, the current density of electrolytic phosphating is 20-40A / dm 2 , the electrolytic phosphating temperature is kept at 10℃-20℃, and the walking speed is kept at 0.8-1.2m / s to control the speed and quality of electrolytic phosphating.

[0101] In the present application, the role of step S201 is to promote the full reaction of the chemical components in the electrolyte, improve the uniformity of the electrolyte, and ensure the normal operation of the electrolytic tank and uniform mass transfer.

[0102] In the present application, the role of step S202 is to ensure the correct connection of the electrodes in the electrolysis process, and the selection and installation of the cathode plate ensure the efficiency and stability of the electrochemical reaction during electrolytic polishing. At the same time, the conductive pressure roller is connected to the positive electrode of the electrolysis power supply, ensuring effective transmission of current and providing reliable electrical conditions for subsequent electrolytic polishing treatment.

[0103] In the present application, the role of step S203 is to pretreat the raw wire, ensure the straightness of the wire through the straightening machine, remove the surface oxide layer and impurities through the abrasive belt machine, and clean the wire surface through the water washing tank to prepare for electrolytic polishing treatment. This series of pretreatment steps ensures that the wire reaches the best state before entering the electrolytic tank, which is beneficial to improve the effect of electrolytic polishing.

[0104] In the present application, the role of step S204 is to realize the electrolytic polishing treatment of the raw wire material by precise control of the current density, polishing temperature and wire running speed. The setting of these parameters ensures the stability of the polishing process and the quality of the polished wire, so that the surface of the wire reaches the expected smoothness and uniformity.

[0105] In the present application, when step S204 is carried out for electrolytic polishing, the surface of the metal substrate acts as an anode to generate an electrochemical reaction under the action of the electrolyte. Due to the overpotential caused by concentration polarization and the difference in electric field distribution caused by the surface topography of the abrasive belt polishing process, the current density of the protruding part of the metal wire surface is much larger than that of the concave part, and the electrochemical reaction of the protruding part is more intense, so the dissolution and release speed of metal cations is faster than that of the concave part. The electrolytic polishing process plays a role in micro-leveling on the surface of the metal substrate. While on the cathode plate, due to the high acidity of the electrolyte, hydrogen is precipitated violently, and due to the impact of a large amount of hydrogen bubbles on the surface of the plate, the reduction of metal cations and the deposition of phosphate on the plate are hindered.

[0106] In the present application, the role of step S205 is to prepare for electrolytic phosphating treatment after electrolytic polishing treatment by switching the process polarity and replacing the electrolytic plate. The selection and installation of the anode plate ensure the efficiency and stability of the electrolytic phosphating reaction, and the conductive pressure roller is connected to the negative electrode of the electrolytic power supply, ensuring the effective transmission of current and providing reliable electrical conditions for subsequent electrolytic phosphating treatment.

[0107] In the present application, the role of step S206 is to further process the polished wire, ensure the straightness of the wire through the straightening machine, and clean the surface of the wire through the water washing tank, preparing for electrolytic phosphating treatment. These steps ensure that the wire is in the best state before entering the electrolytic tank, which is beneficial to improve the effect of electrolytic phosphating. The post-water washing tank cleans the residual electrolyte on the surface of the wire, and the hot air dryer ensures uniform drying of the wire, which is beneficial to improve the application effect of the finished wire.

[0108] In the present application, the role of step S207 is to realize the electrolytic phosphating treatment of the polished wire by precise control of the current density, phosphating temperature and wire running speed. The setting of these parameters ensures the stability of the phosphating process and the quality of the finished wire, so that a uniform and dense phosphating film is formed on the surface of the wire, improving the corrosion resistance and subsequent processing performance of the wire.

[0109] In the present application, when electrolytic phosphating is carried out in step S207, the polished metal substrate surface acts as a cathode to generate an electrochemical reaction under the action of the electrolyte. Since the acidity of the electrolyte is greatly reduced by the previous electrolytic polishing process, the intensity of the hydrogen evolution reaction is greatly reduced, and the disturbance of the bubbles is difficult to interfere with the electrolytic phosphating film forming process. The hydrogen evolution reaction causes the dihydrogen phosphate ion to ionize into hydrogen ion and phosphate ion, and the phosphate ion reaches the saturation point with the metal cation on the interface to deposit on the wire surface in the form of phosphate to form a phosphating film. On the anode plate, oxygen evolution reaction occurs, releasing free acid to replenish the acidity of the electrolyte for subsequent electrolytic polishing process.

[0110] Embodiment 1

[0111] A steel polishing and phosphating integrated electrolyte.

[0112] The following raw materials are included in percentage by weight:

[0113] Phosphoric acid 40%, zinc oxide 25%, citric acid 10%, tartaric acid 10%, ethanol 8%, ammonium sulfate 2%, ferrous ammonium sulfate 2%, benzalacetone 1%, nonylphenol polyoxyethylene ether 0.4%, sodium lauryl alcohol polyether sulfate 0.2%, and the balance is deionized water;

[0114] A preparation method of a steel polishing and phosphating integrated electrolyte.

[0115] S101. Prepare the raw materials according to the weight of each liter of phosphating solution;

[0116] S102. Slowly add phosphoric acid to deionized water, control the stirring speed at 120 r / min, then add zinc oxide in batches, heat to 70℃, and adjust the stirring speed to 200 r / min until the zinc oxide is completely reacted.

[0117] S103. Cool to 50℃, add organic acid, stirring speed 140 r / min, after complete dissolution, add dispersant and polarizer in turn, until all raw materials are completely dissolved.

[0118] S104. Cool to 20℃, add fatty alcohol, stirring speed 120 r / min, after complete dissolution, add inorganic ammonium salt, until completely dissolved, continue stirring for 60 minutes.

[0119] A steel polishing and phosphating integrated process.

[0120] S201. Pour the electrolyte into the electrolytic tank, heat, stir, start the circulating pump, the heating temperature is 50℃, and the stirring speed is kept at 250 r / min;

[0121] S202. Install the cathode plate in the electrolytic cell, connect the conductive pressure roller to the positive pole of the electrolytic power supply, and connect the conductive pressure roller to the negative pole of the electrolytic power supply;

[0122] S203. Connect the raw material wire coil to the straightening machine, sand belt machine, conductive pressure roller, water washing tank, electrolytic cell, post water washing tank, hot air dryer, and inverted wire winding machine in sequence, use a 200 mesh sand belt, and control the temperature of the hot air dryer at 160 DEG C;

[0123] S204. Set the current density, polishing temperature, and wire speed, the current density of electrolytic polishing is 30 A / dm 2 , the electrolytic polishing temperature is maintained at 50 DEG C, the wire speed is maintained at 0.4 m / s, the electrolytic power supply and the inverted wire winding are turned on, the raw material wire is subjected to electrolytic polishing treatment, and the polished wire is obtained;

[0124] S205. Stop heating the tank body, switch the process polarity, replace the electrolytic plate, install the anode plate in the electrolytic cell, connect the conductive pressure roller to the positive pole of the electrolytic power supply, and connect the conductive pressure roller to the negative pole of the electrolytic power supply;

[0125] S206. Connect the polished wire coil to the straightening machine, conductive pressure roller, water washing tank, electrolytic cell, post water washing tank, hot air dryer, and inverted wire winding machine in sequence, and control the temperature of the hot air dryer at 160 DEG C;

[0126] S207. Set the current density, phosphating temperature, and wire speed, the current density of electrolytic phosphating is 40 A / dm 2 , the electrolytic phosphating temperature is maintained at 20 DEG C, the wire speed is maintained at 1.2 m / s, the electrolytic power supply and the inverted wire winding are turned on, and the polished wire is subjected to electrolytic phosphating treatment.

[0127] Example 2

[0128] A steel polishing and phosphating integrated electrolyte.

[0129] The following raw materials are included in percentage by weight:

[0130] Phosphoric acid 30%, zinc oxide 15%, tartaric acid 10%, ethanol 2%, glycerol 2%, ferrous ammonium sulfate 2%, benzalacetone 0.4%, nonylphenol polyoxyethylene ether 0.2%, and the balance is deionized water;

[0131] A preparation method of a steel polishing and phosphating integrated electrolyte.

[0132] S101. Prepare the materials according to the weight of the corresponding raw materials per liter of phosphating solution;

[0133] S102. Slowly add phosphoric acid in deionized water, control the stirring speed at 100 r / min, then add zinc oxide in batches, heat to 60℃, adjust the stirring speed to 160 r / min, until the zinc oxide is completely reacted.

[0134] S103. Cool to 40℃, add organic acid, stirring speed 120 r / min, after completely dissolved, add dispersant and polarizer in turn, until all raw materials are completely dissolved.

[0135] S104. Cool to 10℃, add fatty alcohol, stirring speed 100 r / min, after completely dissolved, add inorganic ammonium salt, until completely dissolved, continue stirring for 30 minutes.

[0136] A steel polishing and phosphating integrated process.

[0137] S201. Pour the electrolyte into the electrolytic tank, heat, stir, start the circulating pump, the heating temperature is 30℃, the stirring speed is kept at 150 r / min;

[0138] S202. Install the cathode plate in the electrolytic tank, connect it to the negative electrode of the electrolysis power supply, and connect the conductive pressure wheel to the positive electrode of the electrolysis power supply;

[0139] S203. Connect the raw material wire coil to the straightening machine, sand belt machine, conductive pressure wheel, water washing tank, electrolytic tank, post water washing tank, hot air dryer, and inverted wire winding machine in turn, use 60 mesh sand belt, and control the temperature of the hot air dryer at 120℃;

[0140] S204. Set the current density, polishing temperature and wire speed, the current density for electrolytic polishing is 10 A / dm 2 , the electrolytic polishing temperature is kept at 30℃, and the wire speed is kept at 0.2 m / s, start the electrolysis power supply and inverted wire winding, and electrolytic polishing treatment is carried out on the raw material wire to obtain polished wire after electrolytic polishing;

[0141] S205. Stop the tank heating, switch the process polarity, replace the electrolytic plate, install the anode plate in the electrolytic tank, connect it to the positive electrode of the electrolysis power supply, and connect the conductive pressure wheel to the negative electrode of the electrolysis power supply;

[0142] S206. Connect the polished wire coil to the straightening machine, conductive pressure wheel, water washing tank, electrolytic tank, post water washing tank, hot air dryer, and inverted wire winding machine in turn, control the temperature of the hot air dryer at 120℃;

[0143] S207. Set the current density, phosphating temperature and wire speed, the current density for electrolytic phosphating is 20 A / dm 2, the electrolytic phosphating temperature is kept at 10℃, the wire speed is kept at 0.8m / s, the electrolysis power is turned on and the inverted wire collecting machine is started, and the polished wire is subjected to electrolytic phosphating treatment.

[0144] Embodiment 3

[0145] A steel polishing and phosphating integrated electrolyte.

[0146] The following raw materials are included in percentage by weight:

[0147] Phosphoric acid 35%, zinc oxide 20%, citric acid 10%, tartaric acid 5%, ethanol 6%, ferrous ammonium sulfate 3%, benzalacetone 0.7%, nonylphenol polyoxyethylene ether 0.3%, sodium lauryl alcohol polyether sulfate 0.1%, and the balance is deionized water;

[0148] A preparation method of a steel polishing and phosphating integrated electrolyte.

[0149] S101. The raw materials are prepared according to the weight of each liter of phosphating solution.

[0150] S102. First, slowly add phosphoric acid to deionized water at a stirring speed of 110r / min, then add zinc oxide in batches, heat to 65℃, and adjust the stirring speed to 180r / min until the zinc oxide is completely reacted.

[0151] S103. Cool to 45℃, add organic acid at a stirring speed of 130r / min, and after complete dissolution, add dispersant and polarizer in sequence until all raw materials are completely dissolved.

[0152] S104. Cool to 15℃, add fatty alcohol at a stirring speed of 110r / min, and after complete dissolution, add inorganic ammonium salt until complete dissolution, and continue stirring for 40 minutes.

[0153] A steel polishing and phosphating integrated process.

[0154] S201. The electrolyte is injected into the electrolysis tank, heated, stirred, and the circulating pump is turned on, the heating temperature is 40℃, and the stirring speed is kept at 200r / min;

[0155] S202. The cathode plate is installed in the electrolysis tank and connected to the negative electrode of the electrolysis power supply, and the conductive pressure roller is connected to the positive electrode of the electrolysis power supply.

[0156] S203. The raw material wire coil is connected to the straightening machine, sanding machine, conductive pressure roller, water washing tank, electrolysis tank, post-water washing tank, hot air dryer, and inverted wire collecting machine in sequence, the sanding machine uses 130# mesh sanding belt, and the hot air dryer temperature is controlled at 140℃.

[0157] S204. Set the current density, polishing temperature and wire speed, the current density of electrolytic polishing is 20A / dm 2 , the electrolytic polishing temperature is maintained at 40℃, the wire speed is maintained at 0.3m / s, the electrolytic power supply is turned on and the inverted take-up is started, the raw material wire is subjected to electrolytic polishing treatment, and the polished wire is obtained;

[0158] S205. Stop the tank heating, switch the process polarity, replace the electrolytic plate, install the anode plate in the electrolytic tank, connect it to the positive pole of the electrolytic power supply, and connect the conductive pressure roller to the negative pole of the electrolytic power supply.

[0159] S206. The polished wire is sequentially connected to the straightening machine, conductive pressure roller, water washing tank, electrolytic tank, post-washing tank, hot air dryer, and inverted take-up machine, with the hot air dryer temperature controlled at 140℃.

[0160] S207. Set the current density, phosphating temperature and wire speed, the current density of electrolytic phosphating is 30A / dm 2 , the electrolytic phosphating temperature is maintained at 15℃, the wire speed is maintained at 1m / s, the electrolytic power supply is turned on and the inverted take-up is started, and the polished wire is subjected to electrolytic phosphating treatment.

[0161] Example 4

[0162] A steel polishing and phosphating integrated electrolyte.

[0163] The following raw materials are included in the weight percentage:

[0164] Phosphoric acid 40%, zinc oxide 25%, citric acid 10%, tartaric acid 10%, ethanol 8%, ammonium sulfate 2%, ferrous ammonium sulfate 2%, benzalacetone 1%, nonylphenol polyoxyethylene ether 0.4%, sodium lauryl polyether sulfate 0.2%, and the balance is deionized water.

[0165] A preparation method of a steel polishing and phosphating integrated electrolyte.

[0166] S101. Prepare the materials according to the weight of each liter of phosphating solution.

[0167] S102. First, slowly add phosphoric acid to the deionized water, control the stirring speed at 100r / min, then add zinc oxide in batches, heat to 60℃, adjust the stirring speed to 160r / min, and continue until the zinc oxide is completely reacted.

[0168] S103. Cool to 40℃, add organic acid, stirring speed 120r / min, after complete dissolution, add dispersant and polarizer in turn, until all raw materials are completely dissolved.

[0169] S104. Cool down to 10℃, add fatty alcohol, stirring speed 100r / min, after complete dissolution, add inorganic ammonium salt, until complete dissolution, continue stirring for 30 minutes.

[0170] A steel polishing and phosphating integrated process.

[0171] S201. Inject electrolyte into the electrolytic tank, heat, stir, start the circulating pump, the heating temperature is 30℃, and the stirring speed is kept at 150r / min;

[0172] S202. Install the cathode plate in the electrolytic tank, connect it with the negative electrode of the electrolysis power supply, and connect the conductive pressure wheel with the positive electrode of the electrolysis power supply;

[0173] S203. Connect the raw material wire coil in sequence to the straightening machine, the sand belt machine, the conductive pressure wheel, the water washing tank, the electrolytic tank, the post water washing tank, the hot air dryer, and the inverted wire collecting machine, use a sand belt with a mesh number of 60, and control the temperature of the hot air dryer at 120℃;

[0174] S204. Set the current density, polishing temperature and wire running speed, the current density for electrolytic polishing is 10A / dm 2 , the electrolytic polishing temperature is kept at 30℃, the wire running speed is kept at 0.2m / s, start the electrolysis power supply and the inverted wire collecting, and electrolytic polishing treatment is performed on the raw material wire to obtain the polished wire after electrolytic polishing;

[0175] S205. Stop the tank heating, switch the process polarity, replace the electrolytic plate, install the anode plate in the electrolytic tank, connect it with the positive electrode of the electrolysis power supply, and connect the conductive pressure wheel with the negative electrode of the electrolysis power supply;

[0176] S206. Connect the polished wire coil in sequence to the straightening machine, the conductive pressure wheel, the water washing tank, the electrolytic tank, the post water washing tank, the hot air dryer, and the inverted wire collecting machine, and control the temperature of the hot air dryer at 120℃;

[0177] S207. Set the current density, phosphating temperature and wire running speed, the current density for electrolytic phosphating is 20A / dm 2 , the electrolytic phosphating temperature is kept at 10℃, the wire running speed is kept at 0.8m / s, start the electrolysis power supply and the inverted wire collecting, and electrolytic phosphating treatment is performed on the polished wire.

[0178] Example 5

[0179] A steel polishing and phosphating integrated electrolyte.

[0180] The following raw materials are included in percentage by weight:

[0181] Phosphoric acid 30%, zinc oxide 15%, tartaric acid 10%, ethanol 2%, glycerol 2%, ferrous ammonium sulfate 2%, benzalacetone 0.4%, nonylphenol polyoxyethylene ether 0.2%, and the balance deionized water;

[0182] A preparation method of a steel polishing and phosphating integrated electrolyte.

[0183] S101. According to the weight of the corresponding raw materials per liter of phosphating solution, the raw materials are prepared;

[0184] S102. Slowly add phosphoric acid in deionized water, control the stirring speed at 120 r / min, then add zinc oxide in batches, heat to 70℃, adjust the stirring speed to 200 r / min, until the zinc oxide is completely reacted.

[0185] S103. Cool to 50℃, add organic acid, stirring speed 140 r / min, after completely dissolved, add dispersant and polarizer in turn, until all raw materials are completely dissolved.

[0186] S104. Cool to 20℃, add fatty alcohol, stirring speed 120 r / min, after completely dissolved, add inorganic ammonium salt, until completely dissolved, continue stirring for 60 minutes.

[0187] A steel polishing and phosphating integrated process.

[0188] S201. Pour the electrolyte into the electrolytic tank, heat, stir, start the circulating pump, the heating temperature is 50℃, the stirring speed is kept at 250 r / min;

[0189] S202. Install the cathode plate in the electrolytic tank, connect it to the negative electrode of the electrolysis power supply, and connect the conductive pressure wheel to the positive electrode of the electrolysis power supply;

[0190] S203. Connect the raw material wire coil to the straightening machine, sand belt machine, conductive pressure wheel, water washing tank, electrolytic tank, post water washing tank, hot air dryer, and inverted wire collecting machine in turn, use 200 mesh sand belt, and control the temperature of the hot air dryer at 160℃;

[0191] S204. Set the current density, polishing temperature and wire running speed, the current density of electrolytic polishing is 30 A / dm 2 , the electrolytic polishing temperature is kept at 50℃, and the wire running speed is kept at 0.4 m / s, start the electrolysis power supply and inverted wire collecting, and electrolytic polishing treatment is performed on the raw material wire to obtain polished wire after electrolytic polishing;

[0192] S205. Stop the tank heating, switch the process polarity, replace the electrolytic plate, install the anode plate in the electrolytic tank, connect it to the positive electrode of the electrolysis power supply, and connect the conductive pressure wheel to the negative electrode of the electrolysis power supply;

[0193] S206. The polished wire coil is sequentially connected to the straightening machine, the conductive pressure roller, the water washing tank, the electrolytic tank, the post-washing tank, the hot air dryer, and the inverted wire collecting machine, and the temperature of the hot air dryer is controlled at 160°C.

[0194] S207. The current density, phosphating temperature, and wire running speed are set, the current density of electrolytic phosphating is 40 A / dm 2 , the electrolytic phosphating temperature is maintained at 20°C, the wire running speed is maintained at 1.2 m / s, the electrolytic power is turned on, and the inverted wire collecting is started, and the polished wire is subjected to electrolytic phosphating treatment.

[0195] Comparative Example 1

[0196] In the formula of the steel polishing and phosphating integrated electrolyte, no fatty alcohol (ethanol) is added, and the other conditions are consistent with those of Example 3.

[0197] Comparative Example 2

[0198] In the formula of the steel polishing and phosphating integrated electrolyte, no polarizing agent (benzylidene acetone) is added, and the other conditions are consistent with those of Example 3.

[0199] Comparative Example 3

[0200] In the preparation process of the steel polishing and phosphating integrated electrolyte, steps S102, S103, and S104 are all heated to a high temperature of 100°C, then the materials are added and mixed, and the other conditions are consistent with those of Example 3.

[0201] Comparative Example 4

[0202] The phosphating solution and the preparation method refer to Example 3 of Chinese Invention Patent CN118497864A. Each liter of the phosphating solution includes the following raw materials: 140 g of phosphoric acid, 82.5 g of zinc oxide, 100 g of calcium nitrate, 4 g of succinic acid, 4 g of citric acid, 4 g of diethylene triamine pentaacetic acid, 4 g of sodium polyacrylate, 0.3 g of cetyltrimethylammonium chloride, and the balance of deionized water. The corresponding raw materials are prepared according to their weights per liter of the phosphating solution. The zinc oxide and the phosphoric acid are added to the deionized water, heated to 65°C, and fully stirred until the zinc oxide reaction is complete, with the stirring speed maintained at 150 r / min during the stirring and dissolution process. The temperature is lowered to 40°C, and the nitrate, polycarboxylate, and cetyltrimethylammonium chloride are added and fully stirred until all the added raw materials are dissolved, with the stirring speed maintained at 120 r / min during the stirring and dissolution process. Then, the succinic acid, citric acid, and diethylene triamine pentaacetic acid are added and stirred until dissolved, and the temperature is lowered to room temperature to obtain the electrolytic phosphating solution. The other conditions are consistent with those of Example 3.

[0203] Comparative Example 5

[0204] In the steel polishing-phosphating integrated process, the current density of the electrolytic polishing in step S204 is set to 0.1 A / dm 2 , the wire drawing speed is set to 1 m / s, the current density of the electrolytic phosphating in step S207 is set to 100 A / dm 2 , the wire drawing speed is set to 0.2 m / s, and the rest of the conditions are consistent with those in Example 3.

[0205] Comparative Example 6

[0206] In the steel polishing-phosphating integrated process, the electrode polarity of step S204 is opposite to that of step S207, and the rest of the conditions are consistent with those in Example 3.

[0207] The finished wire rod after electrolytic polishing and electrolytic phosphating prepared in the above examples and comparative examples was tested for the technical indicators of the phosphating film, and the test results are as follows:

[0208] The Q235 metal base material was subjected to electrolytic polishing and electrolytic phosphating operations according to the requirements of each example and comparative example, and the sample after treatment by electrolytic phosphating alone was tested for surface roughness (Ra) using a roughness measuring instrument. Each group of experiments was tested five times, and the average value was taken. The test results are shown in Table 1.

[0209] Table 1: Roughness detection results of phosphating film

[0210]

[0211] The Q235 metal base material was subjected to electrolytic polishing and electrolytic phosphating operations according to the requirements of each example and comparative example, and the phosphating film layer of Examples 1-5 and Comparative Examples 1-6 was tested for technical indicators of the phosphating film layer. The test results are shown in Table 2.

[0212] The specific detection methods or conditions are as follows:

[0213] ① Adhesion, according to GB / T 1720-2020 paint film circle test.

[0214] ② Corrosion resistance, copper sulfate pitting test. Drop the pitting solution on the sample and observe the time when red corrosion spots appear. The pitting solution is: copper sulfate pentahydrate 41 g, sodium chloride 35 g, 0.1 mol / L hydrochloric acid 13 mL, and distilled water diluted to 1 L.

[0215] ③ Sodium chloride solution immersion. The phosphating sample (room temperature) is immersed in a 3% sodium chloride aqueous solution at room temperature for a specified time, and the phosphating surface is visually inspected for rust.

[0216] ④ Indoor rust prevention. The dried test piece is stored in a room temperature condition with a relative humidity of not more than 70% and no corrosive gas, and the storage time is recorded.

[0217] Table 2 Technical index detection results of phosphating film layer after electrolytic polishing and electrolytic phosphating

[0218]

[0219]

[0220] The Q235 metal substrate was subjected to electrolytic polishing and electrolytic phosphating operations according to the requirements of each example and comparative example. The effects of the phosphating film layer of Example 3 and Comparative Examples 1-6 were observed under a metallographic microscope, and the results are shown in Table 2. Figures 1-7 .

[0221] The metallographic microscope photograph results of Example 3 show that the electrolytic phosphating film layer exhibits excellent uniformity and integrity. The surface of the film layer is smooth, with no obvious pores or defects, indicating that the electrolytic polishing and electrolytic phosphating process can uniformly form a dense and uniform phosphating film. The film layer tightly covers the surface of the wire, showing excellent protective performance, which can effectively resist the erosion of the external environment, ensuring the durability and protection of the Q235 substrate.

[0222] After removing the fatty alcohol in the formula of Comparative Example 1, the roughness after electrolytic phosphating alone reached 2.87 μm, the surface roughness Ra value of the wire after electrolytic polishing reached 3.85 μm, and the roughness after electrolytic phosphating was still as high as 2.54 μm. The phosphating film formed had a thickness of only 2-4 μm, and under a metallographic microscope, it showed obvious unevenness and defect characteristics, with an adhesion level of grade three, a sharp decline in corrosion resistance, and a rust prevention period of less than 10 days. The absence of fatty alcohol led to a decrease in the wettability of the electrolyte on the substrate surface, and the surface tension was not effectively controlled, causing the detachment of gas bubbles to be blocked, which not only affected the microscopic leveling effect of the electrolytic polishing process, but also interfered with the film formation of the electrolytic phosphating reaction.

[0223] After omitting the polarizer in the formula of Comparative Example 2, the roughness after electrolytic phosphating alone reached 2.97 μm, and the surface roughness after electrolytic polishing and phosphating treatment was 3.64 μm and 2.11 μm, respectively. The phosphating film had a thickness of 3-5 μm and had slight defects, with an adhesion level of grade two, a deterioration in corrosion resistance, and a rust prevention period of less than 30 days. Under a metallographic microscope, the deposition effect of the electrolytic phosphating film layer was poor, and it failed to effectively fill the micro concave parts of the substrate surface, directly affecting the formation and quality of the phosphating film layer and reducing the corrosion resistance. The absence of the polarizer disrupted the kinetics control of the electrochemical reaction, leading to a failure to effectively balance the difference in growth rate of metal and metal salt crystals, a decrease in the cathode overpotential adjustment capability, and a damage to the directionality and density of phosphate deposition. The electrolytic phosphating process weakened the improvement effect on the smoothness of the metal substrate surface, leading to an increase in the unevenness of the phosphating film layer and affecting the optimization of the surface roughness.

[0224] After the process temperature of the configuration steps S102-S104 was raised to 100°C in Comparative Example 3, the roughness after separate electrolytic phosphating reached 3.13 μm, the surface roughness after electrolytic polishing increased to 4.03 μm, the phosphating still maintained a relatively high level of 2.89 μm, the uniformity of the film layer deteriorated seriously, the thickness was only 2-4 μm and the adhesion rating was three, the corrosion resistance and rust prevention period were both reduced to a low level, and under the observation of a metallographic microscope, the phosphating film layer had defects such as air holes and increased roughness. The low-temperature feeding process plays an important role in maintaining the activity of the functional components of the electrolyte and the homogeneity of the system. High-temperature treatment destroys the stability of the electrolyte system, leading to degradation or inactivation of heat-sensitive components, which in turn weakens the buffering capacity of the electrolyte in the polishing process and the film-forming driving force of the phosphating reaction.

[0225] The roughness after separate electrolytic phosphating reached 1.92 μm in Comparative Example 4, the surface roughness Ra of the wire after electrolytic polishing was 3.83 μm, and the roughness after electrolytic phosphating still maintained a relatively high level of 1.64 μm. Although the phosphating film had a relatively thick deposition layer of 6-8 μm and a uniform appearance, it had slight defect characteristics, the adhesion reached the first level standard, and the indoor rust prevention period reached 60 days. The formula disclosed in Chinese Invention Patent CN118497864A can meet the basic phosphating requirements, but the component design and process logic do not consider the synergistic adaptability of the electrolytic polishing process at all. Inadequate treatment during electrolytic polishing may result in the failure to effectively remove the oxide layer and impurities in some areas of the substrate surface. On the one hand, the lack of fatty alcohol surfactants in the formula leads to insufficient wettability of the electrolyte, and in the absence of ultrasonic assistance, the surface tension cannot be reduced to promote rapid bubble detachment, resulting in micro-uniform dissolution due to increased bubble disturbance during electrolytic polishing; on the other hand, the formula does not introduce electrochemical regulating components such as polarizers, which makes the dissolution rate of metal cations uncontrollable during electrolytic polishing, and the directional and compactness of phosphate deposition during phosphating is limited, ultimately forming a phosphating film with basic protection function, but the overall performance is still not as good as that of the sample of the embodiment.

[0226] The combination of ultra-low current density and fast walking in the electrolytic polishing stage and the combination of over-high current density and slow walking in the electrolytic phosphating stage of Comparative Example 5 result in a roughness of 4.04 μm after electrolytic phosphating alone, a surface roughness Ra value of 3.90 μm after electrolytic polishing, and a high value of 3.05 μm after electrolytic phosphating. The phosphating film formed under this parameter combination is not only severely uneven, but also has a thickness of only 2-4 μm and obvious defects, an adhesion rating of grade three, and a rust prevention period of less than 10 days. The over-low current density in the polishing stage weakens the driving force for the dissolution of metal cations, resulting in the failure of the electrochemical flattening effect of the micro-protruding parts, while the over-high walking speed exacerbates the imbalance of liquid-phase mass transfer; in the phosphating stage, the over-high current density causes disordered deposition of phosphates, forming a loose and porous film structure, while the over-slow walking speed causes local over-reaction zones, ultimately destroying the integrity and compactness of the film.

[0227] The completely reversed process scheme in Comparative Example 6 in terms of electrode polarity setting results in a roughness of 4.77 μm after electrolytic phosphating alone, an abnormally high surface roughness Ra value of 4.87 μm after electrolytic polishing, and a high value of 4.74 μm after phosphating, with a phosphating film thickness of only 0-1 μm and almost no film formation. When the metal substrate is forced to act as a cathode in the polishing stage, the anodic dissolution reaction that should originally occur is inhibited, instead causing hydrogen evolution and competing with the reduction of metal ions, resulting in surface morphology deterioration, while setting the substrate as an anode in the phosphating stage accelerates the dissolution of the metal matrix rather than the deposition of phosphates, ultimately completely blocking the formation path of the phosphating film, and neither the electrolytic polishing nor the electrolytic phosphating process can effectively proceed, and the phosphating film layer cannot be formed.

[0228] The above is a specific description of the preferred implementation of the present application, but the present application is not limited to the described embodiments, and those skilled in the art can make various equivalent modifications or replacements without deviating from the spirit of the present application, and these equivalent modifications or replacements are all included in the scope defined by the claims of the present application.

Claims

1. An integrated electrolyte for steel polishing and phosphating, characterized in that: Calculated by weight percentage, it includes the following raw materials: Phosphoric acid 30-40%, zinc oxide 15-25%, organic acid 10-20%, fatty alcohol 4-8%, inorganic ammonium salt 2-4%, polarizer 0.4-1%, dispersant 0.2-0.6%, and the balance is deionized water.

2. The steel polishing and phosphating integrated electrolyte according to claim 1, characterized in that: The organic acid is one or more of oxalic acid, citric acid, malic acid, tartaric acid, succinic acid, hydroxyethylidene diphosphonic acid, sodium hydroxyethylidene diphosphate, potassium hydroxyethylidene diphosphate, aminotrimethylene phosphonic acid, ethylenediaminetetramethylenephosphonic acid, and pentasodium ethylenediaminetetramethylenephosphonic acid; The fatty alcohol is one or more of ethanol, glycerol, and hexylene glycol; The inorganic ammonium salt is one or more of ammonium sulfate, ferrous ammonium sulfate, zinc ammonium sulfate, and triammonium phosphate; The polarizing agent is one or more of benzalkyne acetone, o-chlorobenzaldehyde, vanillin, and anisaldehyde; The dispersant is one or more of nonylphenol polyoxyethylene ether, sodium lauryl polyoxyethylene ether sulfate, sodium lauryl polyoxyethylene ether sulfate, sodium dodecylbenzene sulfonate, and potassium dodecylbenzene sulfonate.

3. The steel polishing and phosphating integrated electrolyte according to claim 1, characterized in that: Calculated by weight percentage, it includes the following raw materials: Phosphoric acid 35%, zinc oxide 20%, citric acid 10%, tartaric acid 5%, ethanol 6%, ferrous ammonium sulfate 3%, benzyl acetone 0.7%, nonylphenol polyoxyethylene ether 0.3%, sodium lauryl polyether sulfate 0.1%, and the balance is deionized water.

4. The method for preparing the steel polishing and phosphating integrated electrolyte according to any one of claims 1 to 3, characterized in that: The following steps are involved: (1) adding phosphoric acid and zinc oxide to deionized water, heating and stirring until the zinc oxide is completely reacted to obtain a mixed solution; (2) cooling the mixed solution obtained in step (1), adding an organic acid, a dispersant, and a polarizing agent in sequence, and continuing to stir until all the added raw materials are completely dissolved; (3) The mixed solution obtained in step (2) is further cooled, and then a fatty alcohol is added. After stirring evenly, an inorganic ammonium salt is added and stirred until completely dissolved. The mixture is further stirred to obtain an integrated electrolyte for steel polishing and phosphating.

5. The method for preparing the steel polishing and phosphating integrated electrolyte according to claim 4, characterized in that: Step (1) heating to 60-70°C; Step (2) cooling to 40-50°C; Step (3) continues to cool to 10-20°C.

6. An integrated process for steel polishing and phosphating, characterized in that: The following steps are involved: The steel polishing and phosphating integrated electrolyte according to any one of claims 1 to 3 or the steel polishing and phosphating integrated electrolyte according to any one of claims 4 to 5 is used as an electrolyte to perform electrolytic polishing and electrolytic phosphating on a steel material to obtain a finished steel material after electrolytic polishing and electrolytic phosphating.

7. The steel polishing and phosphating integrated process according to claim 6, characterized in that: The electrolyte used in the electrolytic phosphating treatment is the electrolyte after the electrolytic polishing treatment.

8. The steel polishing and phosphating integrated process according to claim 6, characterized in that: The specific steps include: S201. The steel polishing and phosphating integrated electrolyte is injected into the electrolytic tank, heated, stirred, and the circulation pump is turned on; S202. The cathode plate is installed in the electrolytic cell, connected to the negative electrode of the electrolytic power supply, and the conductive wheel is connected to the positive electrode of the electrolytic power supply; S203. The raw steel material is sequentially connected to a straightening machine, a sanding machine, a conductive pressure wheel, a washing tank, an electrolytic cell, a post-wash tank, a hot air dryer, and an inverted take-up machine; S204 sets the current density, polishing temperature and wire speed, turns on the electrolytic power supply and inverted take-up, electrolytically polishes the raw steel material to obtain a polished steel material after electrolytic polishing; S205. Stop heating the tank, switch the process polarity, replace the electrolytic plate, install the anode plate in the electrolytic cell, connect it to the positive electrode of the electrolytic power supply, and connect the conductive wheel to the negative electrode of the electrolytic power supply; S206. The polished steel material after electrolytic polishing is sequentially connected to a straightening machine, a conductive pressure wheel, a washing tank, an electrolytic tank, a post-wash tank, a hot air dryer, and an inverted take-up machine; S207. Set the current density, phosphating temperature and wire speed, turn on the electrolytic power supply and inverted wire take-up, perform electrolytic phosphating treatment on the polished steel material, and obtain the finished steel material after electrolytic polishing and electrolytic phosphating.

9. The steel polishing and phosphating integrated process according to claim 8, characterized in that: In step S201, the heating temperature is 30°C-50°C, and the stirring speed is maintained at 150-250 r / min; In step S204, the current density of electrolytic polishing is 10-30A / dm 2 , the polishing temperature of electrolytic polishing is maintained at 30℃-50℃, and the line speed is maintained at 0.2-0.4m / s; In step S207, the current density of electrolytic phosphating is 20-40A / dm 2 The phosphating temperature of electrolytic phosphating is maintained at 10℃-20℃, and the wiring speed is maintained at 0.8-1.2m / s.

10. A finished steel product after electrolytic polishing and electrolytic phosphating, characterized in that: The steel polishing and phosphating integrated process is prepared by any one of claims 6 to 9.

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