CN114773937A - Phosphate-free sheet based on endless rolling process and preparation method thereof - Google Patents

Abstract

The invention belongs to the field of metal materials, and particularly relates to a preparation method of a non-phosphating plate based on a headless rolling process, which comprises the following steps: adopting ultrathin hot-rolled strip steel produced by a headless rolling process as a substrate without phosphating treatment; removing an oxide layer of the substrate by a continuous pickling line, and then ensuring the cleanliness of the surface of the substrate through a rinsing process; preparing a metal surface treating agent; and coating the prepared metal surface treating agent on the surface of a substrate by a roller coating process, and drying to prepare the phosphating-free plate. The preparation method provided by the invention can save equipment, labor, time and environmental cost of a phosphating process, can provide the phosphating-free process steel coil meeting the requirements of environmental protection, energy conservation and low emission, is directly used by downstream customers, and solves the fundamental problem for industrial application, so that coating users can save relevant processes of alkali washing, neutralization, surface adjustment and phosphating, directly spray paint or plastic, and simultaneously eliminate environmental pollution of the users in a series of pretreatment processes.

Description

Phosphate-free sheet based on endless rolling process and preparation method thereof

technical field

The invention belongs to the field of metal materials, in particular to a phosphate-free plate based on an endless rolling process and a preparation method thereof, and in particular to an environmental protection, energy-saving and low-emission material that can be directly used for painting or plastic spraying by downstream coating customers Phosphate-free board and preparation method thereof.

Background technique

In industries such as electrical cabinets, surface pretreatment is required before spraying or painting to remove oil and film to improve surface adhesion. Common processes are phosphating and shot blasting, of which phosphating is the most widely used. The traditional phosphating process contains zinc, manganese, nickel and other heavy metal ions and a large amount of phosphorus. It is difficult to discharge and treat wastewater, and it can no longer meet the national environmental protection requirements for the coating industry. At the same time, a large amount of phosphating slag will be generated during the phosphating process, which requires a corresponding slag removal device, and the phosphating temperature is 30 ~ 50 ℃, and auxiliary heating equipment and heat sources are also required to heat the phosphating tank. After chemical treatment, a large amount of overflow water is required to rinse the workpiece, which not only has a high production cost, but also causes environmental pollution.

As the country pays close attention to environmental protection in recent years, the phosphating process is a high-polluting industry and is subject to key monitoring, forcing phosphating customers to adopt the following process paths: (1) The purchase of a large number of environmental protection equipment leads to huge investment and high operating costs; (2) The use of plating Zinc plate; not only does the cost per ton of steel increase by 500 yuan or more, but also the adhesion of the coating is poor, the zinc layer affects the welding quality and causes zinc fume pollution to endanger human health; (3) phosphating will also be carried out in areas where the external environmental protection pressure is small. The transportation cycle will be long and the cost will be high.

SUMMARY OF THE INVENTION

In view of this, the purpose of the present invention is to provide a method for preparing a phosphate-free sheet based on an endless rolling process, aiming to solve the environmental problems and costs that are difficult to handle in the traditional phosphating process encountered by coating users in the downstream industry question.

Another object of the present invention is to provide a phosphating-free sheet produced based on the endless rolling process, which aims to save the equipment, manpower, time and environmental protection cost of the power-transferring phosphating process, and can be directly provided for customers to use The phosphate-free steel coil will solve fundamental problems for industrial applications.

In order to achieve the above-mentioned purpose of the invention, the technical solutions adopted are as follows:

The preparation method of the phosphate-free plate based on the endless rolling process includes the following steps:

(1) The 0.8-1.5mm ultra-thin hot-rolled strip produced by the endless rolling process is used as the substrate free of phosphating treatment;

(2) After removing the oxide layer of the substrate through the continuous pickling unit, after rinsing with deionized water, the cleanliness of the surface of the substrate is ensured; wherein, the technical index of the deionized water is: electrical conductivity <10μS/ cm, PH value 6~7, chloride ion ≤2.8mg/L, soluble SiO ₂ ≤0.2mg/L;

(3) Prepare a metal surface treatment agent, which is composed of the following parts by weight of raw materials: 1-5 parts of silane coupling agent; 1-5 parts of modified resin; 0.5-2.5 parts of hydrolysis stabilizer; curing agent 1.5-2.5 parts, 10-25 parts of alcohol; 60-86 parts of deionized water, and configured by the following preparation method. The configuration process is as follows: add 10-25 parts of alcohol and 5-20 parts of deionized water into the configuration container in sequence. and 0.5-2.5 parts of hydrolysis stabilizer, and then under the condition of shearing and stirring, add 1-5 parts of silane coupling agent and 1-5 parts of modified resin into its configuration container, and stir at room temperature for 1-5 parts 3.5 hours, after the stirring reaction is over, add 1.5-2.5 parts of the curing agent to the configuration container and stir evenly, and finally add the remaining deionized water to the configuration container to form a metal surface treatment agent; wherein, step (3) The deionized water used in step (2) is the same as the deionized water used in step (2);

(4) The metal surface treatment agent configured in step (3) is coated on the surface of the substrate after rinsing in step (2) by a roller coating process and dried to form a phosphate-free board, wherein the drying temperature is 200-350 ℃, the drying time is 2-10s, and the plate surface temperature of the phosphate-free board out of the drying oven is ≥50℃.

Further, the unevenness of the board surface of the substrate is less than or equal to 15I, and the roughness Ra: 0.5-2.0 μm.

Preferably, the silane coupling agent is methacryloxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, methyltrimethoxysilane, methyltriethoxysilane, propyl group One or more of trimethoxysilane and propyltriethoxysilane.

Preferably, the modified resin is selected from one or more of modified acrylic resin, modified alkyd resin, and modified polyester resin.

Preferably, the hydrolysis stabilizer is selected from one of nonionic acrylamide and fatty acid polyethylene glycol ester.

Preferably, the curing agent is one of trioxymethylene and anhydrous ethylenediamine; the alcohol is selected from one or more of methanol, ethanol, and propanol.

More preferably, the roller coating process adopts the method of smooth coating or reverse coating. After the metal surface treatment agent is evenly coated on the upper and lower surfaces of the rinsed substrate, a coating film will be formed, and a phosphate-free plate will be formed after drying. The weight of the single-sided coating film in the phosphate-free board is greater than or equal to 0.3 g/㎡, and the film thickness of the coating film is 2 μm.

Further, the substrate enters into a continuous pickling machine for pickling after unwinding—laser welding—phosphorus breaking and straightening.

Further, after the rinsed substrate is processed by the leveling process, the metal surface treatment agent is applied to the surface of the substrate by a roller coating process and then dried, and after the drying is completed, it is coiled to form a phosphate-free steel coil for downstream use. user use.

The present invention also provides a phosphate-free sheet produced based on an endless rolling process, and the phosphate-free sheet is made based on the above-mentioned preparation method.

Beneficial effects of the present invention:

The preparation method of the phosphating-free sheet based on the endless rolling process provided by the invention can save the equipment, labor, time and environmental protection cost of the phosphating process, and can provide the phosphating-free process steel that satisfies environmental protection, energy saving and low emission The coil, which is directly used by downstream customers, will solve fundamental problems for industrial applications; thus, coating users will save the related processes of alkali washing, neutralization, surface conditioning and phosphating, and directly spray paint or plastic. At the same time, it also eliminates the environmental pollution of users in a series of pretreatment processes. In addition, the present invention also has the following advantages:

(1) The present invention adopts ultra-thin hot-rolled strip steel as the substrate without phosphating treatment, and achieves the goal of reducing manufacturing costs by replacing cooling with heat;

(2) The present invention adopts a specially configured metal surface treatment agent, which can form a silanized film with a thickness of 2 μm on the phosphating-free coil after roller coating, so that the phosphate-free coil has good heat resistance and acid resistance. Alkaline, which not only inhibits the diffusion of internal pitting corrosion, but also relieves the speed of external acid-base electrochemical corrosion. At the same time, the steel coil treated with it can meet the anti-rust performance requirements of the phosphating-free coil without oiling. , and take into account the performance of traditional phosphating coating adhesion.

Description of drawings

In order to explain the embodiments of the present invention or the technical solutions in the prior art more clearly, the following briefly introduces the accompanying drawings that need to be used in the description of the embodiments or the prior art. Obviously, the accompanying drawings in the following description are only These are some embodiments of the present invention, and for those of ordinary skill in the art, other drawings can also be obtained from these drawings without any creative effort.

Fig. 1 is the flow chart that the present invention produces phosphating-free plate based on endless rolling process;

FIG. 2 is a flow chart of producing a phosphating-free substrate by the endless rolling process involved in the present invention.

Detailed ways

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

Due to the country's high-quality requirements for environmental protection in recent years, coating users are forced to change the traditional phosphating process or abandon the original phosphating process in order to meet the country's requirements for environmental protection, energy saving and low emissions.

In this regard, downstream coating users urgently need a treatment process and steel that meet the above-mentioned high-quality environmental protection requirements to solve the problems they are facing now. Thus, the application of the present invention is born.

The present invention adopts ultra-thin hot-rolled strip steel as the substrate without phosphating treatment, and achieves the goal of reducing the manufacturing cost by replacing cooling with heat; meanwhile, the present invention adopts a specially configured metal surface treatment agent, which is coated by rollers. After drying, a 2μm silanized film can be formed on the phosphate-free coil, which makes the phosphate-free coil have good heat resistance, acid and alkali resistance, which not only inhibits the diffusion of internal pitting corrosion, but also relieves external acid. At the same time, the steel coil treated with it can not only meet the anti-rust performance requirements of the phosphating-free coil without oiling, but also take into account the performance of the traditional phosphating coating adhesion.

Before the technical solution of the present invention is described in detail, a brief introduction to the endless rolling process involved in the present invention is required.

Endless rolling process is a technological breakthrough in traditional hot-rolled strip production. It refers to a technology in which rough-rolled slabs are welded on the intermediate roller table and continuously pass through the finishing mill. Compared with the traditional production method, due to the reduction of strip threading and tailing in the finishing mill, the strip is rolled under constant tension conditions, so the geometric accuracy of the strip head and tail and the proportion of poor shape are greatly reduced. , the mechanical properties are more uniform, the yield is increased, the labor productivity of the unit is improved, and the ultra-thin strip can be produced stably in large quantities.

Endless or semi-endless rolling keeps the entire coil at a constant tension to achieve stable rolling, and there is no plate thickness change and plate crown change caused by prediction errors and adjustment errors caused by thermal expansion and wear models of the rolls, which can significantly improve Plate thickness accuracy. The thickness accuracy of the ultra-thin tropical belt can reach ±30μm, and the pass rate is over 99%. The ultrathin tropics also showed excellent elongation and normal microstructure.

As shown in Figure 2, the process of stably producing ultra-thin hot-rolled strip by the endless rolling process is: continuous casting - rough rolling in a large reduction mill - induction heating - - finishing rolling Scale----finishing rolling----laminar cooling----high speed flying shear coiling----coiling.

Continuous casting - using a straight arc continuous casting machine to cast a suitable billet at high drawing speed; rough rolling with a large reduction rolling mill - pressing the billet through a rolling mill into a suitable intermediate billet; induction heating - realizing intermediate Compensation heating of the billet, the maximum temperature rise can reach 300 degrees, reducing the rolling force of finishing rolling; finishing rolling and descaling - descaling by high-pressure water to remove iron oxide scale on the surface of the strip; finishing - five-stand finishing rolling to achieve customer satisfaction Thickness and width required; laminar cooling - a laminar cooling device with a high-level water tank is used, the header is controlled by a flow valve, the header flow is precisely controlled, the cooling rate of the strip is precisely controlled, and the mechanical properties of the strip are effectively controlled. High-speed flying shear - in the headless production mode, the strip steel with thickness of 0.8-4mm is cut into coils.

The 0.8-1.5mm ultra-thin hot-rolled strip produced by the above-mentioned endless rolling process is used as the substrate for phosphating-free treatment of the present invention, and further research and development is carried out on this basis, and finally the technical solution of the present invention is formed. .

The technical solution of the present invention will be described in detail below with reference to FIG. 1 .

Example 1

The preparation method of the phosphate-free plate based on the endless rolling process provided by the present invention comprises the following steps:

(1) The 0.8mm ultra-thin hot-rolled strip steel produced by the endless rolling process is used as the substrate without phosphating treatment; the plate surface roughness of the substrate is ≤15I, and the roughness Ra: 2.0μm. After the uncoiling process, the laser welding process, and the phosphorus breaking and straightening process, the substrate enters the continuous pickling machine for pickling.

Laser welding in this step: using a German Mi 8 Hz laser welding machine to realize the continuous production function of connecting the front and rear coils with the head and tail; Continuous pickling: The surface scale is removed by turbulent pickling of strip in shallow grooves.

(2) After removing the oxide layer of the substrate through the continuous pickling unit, after rinsing with deionized water, the cleanliness of the surface of the substrate is ensured; wherein, the technical index of the deionized water is: electrical conductivity <10μS/ cm, PH=6, chloride ion≤2.8mg/L, soluble SiO ₂ ≤0.2mg/L.

(3) Prepare a metal surface treatment agent, which is composed of the following parts by weight of raw materials: 1 part of silane coupling agent; 1 part of modified resin; 0.5 part of hydrolysis stabilizer; 1.5 parts of curing agent and 10 parts of alcohol 60 parts of deionized water, and configured by the following preparation method, the configuration process is as follows: add 10 parts of alcohol, 5 parts of deionized water and 0.5 part of hydrolysis stabilizer successively to the configuration container, then under the condition of shearing and stirring, Then add 1 part of silane coupling agent and 1 part of modified resin to its configuration container, and stir and react at room temperature for 1 hour. After the stirring reaction is completed, add 1.5 parts of curing agent to its configuration container and stir evenly. Finally, the remaining deionized water is added to the preparation container to form the metal surface treatment agent. The deionized water used in this process is the same substance as the deionized water used in step (2).

In this embodiment, the silane coupling agent is methacryloxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, methyltrimethoxysilane, methyltriethoxysilane , one or more of propyltrimethoxysilane and propyltriethoxysilane; the modified resin is selected from one of modified acrylic resin, modified alkyd resin and modified polyester resin or more; the hydrolysis stabilizer is selected from one of non-ionic acrylamide and fatty acid polyethylene glycol ester; the curing agent is one of trioxymethylene and anhydrous ethylenediamine; the alcohol One or more selected from methanol, ethanol, and propanol.

(4) After rinsing, the substrate is processed by the leveling process, and then the metal surface treatment agent is applied to the surface of the substrate by the roller coating process, and then dried. After the drying is completed, it is coiled to form a phosphate-free steel coil for downstream use. user use. Among them, the drying temperature is 200°C, the drying time is 2s, and the surface temperature of the phosphating-free board out of the drying oven is ≥50°C; and the roller coating process adopts the method of smooth coating or reverse coating to treat the metal surface After the agent is evenly applied to the upper and lower surfaces of the rinsed substrate, a coating film will be formed, and after drying, a phosphate-free board will be formed. The film thickness is 2 μm.

In this step, the purpose of leveling is to control the surface roughness of the strip steel and remove the yield platform of the low-carbon mild steel; roller coating: apply the coating liquid to the upper and lower surfaces of the strip steel evenly and effectively; drying: by using waste heat, burner and electric Heating is carried out by heating, so that the coating liquid is cured and effectively combined with the strip.

Example 2

The preparation method of the phosphate-free plate based on the endless rolling process provided by the present invention comprises the following steps:

(1) The 1.0mm ultra-thin hot-rolled strip steel produced by the endless rolling process is used as the substrate without phosphating treatment; the surface roughness of the substrate is ≤15I, and the roughness Ra: 0.7 μm, and then the obtained After the uncoiling process, the laser welding process, and the phosphorus breaking and straightening process, the substrate enters the continuous pickling machine for pickling.

(2) After removing the oxide layer of the substrate through the continuous pickling unit, after rinsing with deionized water, the cleanliness of the surface of the substrate is ensured; wherein, the technical index of the deionized water is: electrical conductivity <10μS/ cm, PH=6, chloride ion≤2.8mg/L, soluble SiO ₂ ≤0.2mg/L.

(3) Prepare a metal surface treatment agent, which is composed of the following raw materials by weight: 2 parts of silane coupling agent; 3 parts of modified resin; 1.4 parts of hydrolysis stabilizer; 2.2 parts of curing agent and 17 parts of alcohol 73 parts of deionized water, and configured by the following preparation method, the configuration process is as follows: add 17 parts of alcohol, 11 parts of deionized water and 1.4 parts of hydrolysis stabilizer successively to the configuration container, then under the condition of shearing and stirring, Then add 2 parts of silane coupling agent and 3 parts of modified resin into its configuration container, and stir and react at room temperature for 2.2 hours. After the stirring reaction is completed, add 2.2 parts of curing agent to its configuration container and stir evenly. Finally, the remaining deionized water is added to the preparation container to form the metal surface treatment agent. The deionized water used in this process is the same substance as the deionized water used in step (2).

In this embodiment, the silane coupling agent is methacryloxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, methyltrimethoxysilane, methyltriethoxysilane , one or more of propyltrimethoxysilane and propyltriethoxysilane; the modified resin is selected from one of modified acrylic resin, modified alkyd resin and modified polyester resin or more; the hydrolysis stabilizer is selected from one of non-ionic acrylamide and fatty acid polyethylene glycol ester; the curing agent is one of trioxymethylene and anhydrous ethylenediamine; the alcohol One or more selected from methanol, ethanol, and propanol.

(4) After rinsing, the substrate is processed by the leveling process, and then the metal surface treatment agent is applied to the surface of the substrate by the roller coating process, and then dried. After the drying is completed, it is coiled to form a phosphate-free steel coil for downstream use. user use. Among them, the drying temperature is 280°C, the drying time is 5s, and the surface temperature of the phosphating-free board out of the drying oven is ≥50°C; and the roller coating process adopts the method of smooth coating or reverse coating to treat the metal surface. After the agent is evenly applied to the upper and lower surfaces of the rinsed substrate, a coating film will be formed, and after drying, a phosphate-free board will be formed. The film thickness is 2 μm.

Example 3

The preparation method of the phosphate-free plate based on the endless rolling process provided by the present invention comprises the following steps:

(1) The 1.2mm ultra-thin hot-rolled strip steel produced by the endless rolling process is used as the substrate without phosphating treatment; the plate surface roughness of the substrate is ≤15I, and the roughness Ra: 1.8μm. After the uncoiling process, the laser welding process, and the phosphorus breaking and straightening process, the substrate enters the continuous pickling machine for pickling.

(2) After removing the oxide layer of the substrate through the continuous pickling unit, after rinsing with deionized water, the cleanliness of the surface of the substrate is ensured; wherein, the technical index of the deionized water is: electrical conductivity <10μS/ cm, PH=7, chloride ion≤2.8mg/L, soluble SiO ₂ ≤0.2mg/L.

(3) Prepare a metal surface treatment agent, which consists of the following raw materials by weight: 4 parts of silane coupling agent; 2 parts of modified resin; 2.3 parts of hydrolysis stabilizer; 1.8 parts of curing agent and 19 parts of alcohol 80 parts of deionized water, and configured by the following preparation method, and the configuration process is as follows: add 19 parts of alcohol, 15 parts of deionized water and 2.3 parts of hydrolysis stabilizer to the configuration container successively, and then under the condition of shearing and stirring, Then add 4 parts of silane coupling agent and 2 parts of modified resin into its configuration container, and stir and react at room temperature for 3.4 hours. After the stirring reaction is over, add 1.8 parts of curing agent to its configuration container and stir evenly. Finally, the remaining deionized water is added to the preparation container to form the metal surface treatment agent. The deionized water used in this process is the same substance as the deionized water used in step (2).

In this embodiment, the silane coupling agent is methacryloxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, methyltrimethoxysilane, methyltriethoxysilane , one or more of propyltrimethoxysilane and propyltriethoxysilane; the modified resin is selected from one of modified acrylic resin, modified alkyd resin and modified polyester resin or more; the hydrolysis stabilizer is selected from one of non-ionic acrylamide and fatty acid polyethylene glycol ester; the curing agent is one of trioxymethylene and anhydrous ethylenediamine; the alcohol One or more selected from methanol, ethanol, and propanol.

(4) After rinsing, the substrate is processed by the leveling process, and then the metal surface treatment agent is applied to the surface of the substrate by the roller coating process, and then dried. After the drying is completed, it is coiled to form a phosphate-free steel coil for downstream use. user use. Among them, the drying temperature is 330°C, the drying time is 8s, and the surface temperature of the phosphating-free board out of the drying oven is ≥50°C; and the roller coating process adopts the method of smooth coating or reverse coating to treat the metal surface. After the agent is evenly applied to the upper and lower surfaces of the rinsed substrate, a coating film will be formed, and after drying, a phosphate-free board will be formed. The film thickness is 2 μm.

Example 4

The preparation method of the phosphate-free plate based on the endless rolling process provided by the present invention comprises the following steps:

(1) The 1.5mm ultra-thin hot-rolled strip steel produced by the endless rolling process is used as the substrate without phosphating treatment; the plate surface roughness of the substrate is ≤15I, and the roughness Ra: 0.5μm. After the uncoiling process, the laser welding process, and the phosphorus breaking and straightening process, the substrate enters the continuous pickling machine for pickling.

(2) After removing the oxide layer of the substrate through the continuous pickling unit, after rinsing with deionized water, the cleanliness of the surface of the substrate is ensured; wherein, the technical index of the deionized water is: electrical conductivity <10μS/ cm, PH=7, chloride ion≤2.8mg/L, soluble SiO ₂ ≤0.2mg/L.

(3) Prepare a metal surface treatment agent, which consists of the following raw materials by weight: 5 parts of silane coupling agent; 5 parts of modified resin; 2.5 parts of hydrolysis stabilizer; 2.5 parts of curing agent and 25 parts of alcohol 86 parts of deionized water, and configured by the following preparation method, the configuration process is as follows: add 25 parts of alcohol, 20 parts of deionized water and 2.5 parts of hydrolysis stabilizer successively to the configuration container, then under the condition of shearing and stirring, Then add 5 parts of silane coupling agent and 5 parts of modified resin into its configuration container, and stir and react at room temperature for 3.5 hours. After the stirring reaction is completed, add 2.5 parts of curing agent to its configuration container and stir evenly. Finally, the remaining deionized water is added to the preparation container to form the metal surface treatment agent. The deionized water used in this process is the same substance as the deionized water used in step (2).

In this embodiment, the silane coupling agent is methacryloxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, methyltrimethoxysilane, methyltriethoxysilane , one or more of propyltrimethoxysilane and propyltriethoxysilane; the modified resin is selected from one of modified acrylic resin, modified alkyd resin and modified polyester resin or more; the hydrolysis stabilizer is selected from one of non-ionic acrylamide and fatty acid polyethylene glycol ester; the curing agent is one of trioxymethylene and anhydrous ethylenediamine; the alcohol One or more selected from methanol, ethanol, and propanol.

(4) After rinsing, the substrate is processed by the leveling process, and then the metal surface treatment agent is applied to the surface of the substrate by the roller coating process, and then dried. After the drying is completed, it is coiled to form a phosphate-free steel coil for downstream use. user use. Among them, the drying temperature is 350°C, the drying time is 10s, and the surface temperature of the phosphating-free board out of the drying oven is ≥50°C; and the roller coating process adopts the method of smooth coating or reverse coating to treat the metal surface. After the agent is evenly applied to the upper and lower surfaces of the rinsed substrate, a coating film will be formed, and after drying, a phosphate-free board will be formed. The film thickness is 2 μm.

According to the above-mentioned Embodiments 1-4 of the present invention, four kinds of phosphate-free boards with different specifications will be formed.

Four different specifications of phosphating-free plates were used as the experimental group and the control group (steel plates formed by traditional phosphating process) to conduct plastic spraying experiments, and the bonding force, adhesion, environmental protection and corrosion resistance were tested. The test data are as follows :

serial number Example Coating adhesion Coating Adhesion Environmentally friendly Corrosion resistance Weldability 1 Example 1 excellent T-bend performance = 2T no pollution excellent excellent 2 Example 2 excellent T-bend performance = 2T no pollution excellent excellent 3 Example 3 excellent T-bend performance = 2T no pollution excellent excellent 4 Example 4 excellent T-bend performance = 2T no pollution excellent excellent 5 Phosphating excellent T-bend performance = 3T heavy pollution excellent excellent

To sum up, it can be seen that the phosphate-free board is a pollution-free process, and the phosphate board is a heavily polluted process. The T-bending performance of the phosphating-free sheet is 2T, and the T-bending performance of the phosphating sheet is 3T. The adhesion of the phosphate-free coating is better than that of the phosphating sheet. Other coatings are comparable in adhesion, corrosion resistance and weldability. The performance of the phosphate-free board is much better than that of the phosphate board.

The specific application cases of the phosphate-free board prepared by the present invention are as follows:

Example 5: Panel application of high and low switch cabinets. Spray orange pattern plastic, the plastic layer is between 60~80μm, the baking temperature is 180~220℃, and the baking time is 30 minutes. After the cross-cut test, it meets the requirements of grade 0, and the reverse knock test does not show that the plastic powder falls off into pieces, which meets the customer's use requirements.

Example 6: Box-to-cabinet door panel, bending, punching, and welding in the molding process meet customer requirements. The thickness of the plastic spray layer is between 80μm and 100μm, the baking temperature is 200℃, and the baking time is 20min. The cross-cut test and the impact test are all qualified.

Finally, it should be noted that the above are only preferred embodiments of the present invention, and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, for those skilled in the art, it is still The technical solutions described in the foregoing embodiments can be modified, or some technical features thereof can be equivalently replaced, and any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included. within the protection scope of the present invention.

Claims (10)

1. the preparation method of phosphating-free plate based on endless rolling process, is characterized in that, comprises the following steps: (1) The 0.8-1.5mm ultra-thin hot-rolled strip produced by the endless rolling process is used as the substrate free of phosphating treatment; (2) After removing the oxide layer of the substrate through the continuous pickling unit, after rinsing with deionized water, the cleanliness of the surface of the substrate is ensured; wherein, the technical index of the deionized water is: electrical conductivity <10μS/ cm, PH value 6~7, chloride ion ≤2.8mg/L, soluble SiO ₂ ≤0.2mg/L; (3) Prepare a metal surface treatment agent, which is composed of the following parts by weight of raw materials: 1-5 parts of silane coupling agent; 1-5 parts of modified resin; 0.5-2.5 parts of hydrolysis stabilizer; curing agent 1.5-2.5 parts, 10-25 parts of alcohol; 60-86 parts of deionized water, and configured by the following preparation method. The configuration process is as follows: add 10-25 parts of alcohol and 5-20 parts of deionized water into the configuration container in sequence. and 0.5-2.5 parts of hydrolysis stabilizer, and then under the condition of shearing and stirring, add 1-5 parts of silane coupling agent and 1-5 parts of modified resin into its configuration container, and stir at room temperature for 1-5 parts 3.5 hours, after the stirring reaction is over, add 1.5-2.5 parts of the curing agent to the configuration container and stir evenly, and finally add the remaining deionized water to the configuration container to form a metal surface treatment agent; wherein, step (3) The deionized water used in step (2) is the same as the deionized water used in step (2); (4) The metal surface treatment agent configured in step (3) is coated on the surface of the substrate after rinsing in step (2) by a roller coating process and dried to form a phosphate-free board, wherein the drying temperature is 200-350 ℃, the drying time is 2-10s, and the plate surface temperature of the phosphate-free board out of the drying oven is ≥50℃. 2 . The method for preparing a phosphate-free plate based on an endless rolling process according to claim 1 , wherein the surface roughness of the substrate is less than or equal to 15I, and the roughness Ra: 0.5-2.0 μm. 3 . 3. The method for preparing a phosphate-free plate based on an endless rolling process according to claim 2, wherein the silane coupling agent is methacryloxysilane, vinyltrimethoxysilane, ethylene One or more of triethoxysilane, methyltrimethoxysilane, methyltriethoxysilane, propyltrimethoxysilane and propyltriethoxysilane. 4. The method for preparing a phosphate-free plate based on an endless rolling process according to claim 2, wherein the modified resin is selected from the group consisting of modified acrylic resin, modified alkyd resin, and modified polyester resin one or more of. 5. the preparation method of phosphate-free plate based on endless rolling process according to claim 2, is characterized in that, described hydrolysis stabilizer is selected from the one in nonionic acrylamide, fatty acid polyethylene glycol ester . 6. the preparation method of phosphating-free board based on endless rolling process according to claim 2, is characterized in that, described curing agent is a kind of in trioxymethylene, anhydrous ethylenediamine; One or more of methanol, ethanol, and propanol. 7. The preparation method of phosphate-free plate based on endless rolling process according to claim 2, characterized in that, the roller coating process adopts the mode of smooth coating or reverse coating, and the metal surface treatment agent is evenly coated on the rinsing A coating film will be formed on the upper and lower surfaces of the rear substrate, and a phosphate-free board will be formed after drying. . 8. The method for preparing a phosphate-free plate based on an endless rolling process according to claim 1, wherein the substrate enters a continuous pickling machine after being uncoiled - laser welding - broken phosphorus and straightened wash. 9 . The method for preparing a phosphate-free plate based on an endless rolling process according to claim 8 , wherein the substrate after rinsing is processed by a flattening process and then coated with a metal surface treatment agent by a roller coating process. 10 . After drying on the surface of the substrate, it is coiled after drying to form a phosphating-free steel coil for use by downstream users. 10. A phosphate-free sheet produced based on an endless rolling process, which is made based on the preparation method of any one of claims 1-9.

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