阅读说明：本技术 一种钢材预处理方法 (Steel pretreatment method ) 是由 陈强 肖艳 陶加法 周增光 刘华学 陈文兴 刘军祥 石忠华 于 2019-08-28 设计创作，主要内容包括：本发明公开了一种钢材预处理方法,所述方法包括：在经所述抛丸工艺处理后,对所述钢材的表面进行温度检测,获取所述钢材的表面温度值；判断所述表面温度值是否高于预设温度值；若否,则空气启动所述预热工艺,在所述钢材进入喷漆室前,对所述钢材进行预热；控制所述钢材进入喷涂工艺,使用空气喷涂工艺对所述钢材的表面进行水性涂料喷涂,使所述钢材的表面形成均匀的水性涂料膜,获得成膜后的钢材；控制所述成膜后的钢板进入烘干工艺进行烘干,获得半干后的钢材；控制所述半干后的钢材进入吹风工艺进行吹风,使水性涂料涂膜达到干燥,获得预处理后的钢材；可实现在目前快速钢材抛丸预处理线上使用环保、安全的水性涂料。(The invention discloses a steel pretreatment method, which comprises the following steps: after the shot blasting process is carried out, carrying out temperature detection on the surface of the steel to obtain a surface temperature value of the steel; judging whether the surface temperature value is higher than a preset temperature value or not; if not, starting the preheating process by air, and preheating the steel before the steel enters a paint spraying chamber; controlling the steel to enter a spraying process, and spraying water-based paint on the surface of the steel by using an air spraying process to form a uniform water-based paint film on the surface of the steel to obtain the film-formed steel; controlling the film-formed steel plate to enter a drying process for drying to obtain a semi-dried steel material; controlling the semi-dried steel to enter a blowing process for blowing so that a water-based paint film is dried to obtain pretreated steel; can realize the use of environment-friendly and safe water-based paint on the prior rapid steel shot blasting pretreatment line.)

1. A steel pretreatment method is applied to a steel shot blasting pretreatment line which sequentially comprises a shot blasting process, a spraying process and a drying process, and is characterized in that a preheating process is arranged between the shot blasting process and the spraying process, and an air blowing process is arranged after the drying process;

The method comprises the following steps:

after the shot blasting process is carried out, carrying out temperature detection on the surface of the steel to obtain a surface temperature value of the steel;

Judging whether the surface temperature value is higher than a preset temperature value or not;

If not, starting the preheating process by air, and preheating the steel before the steel enters a paint spraying chamber to enable the surface temperature of the steel to be 15-40 ℃;

Controlling the steel to enter a spraying process; wherein, in the spraying process, based on an air spraying mode, the surface of the steel is sprayed by using a water-based paint, so that a uniform water-based paint film is formed on the surface of the steel, and the film-formed steel is obtained, wherein the thickness of the water-based paint film is 10-15 μm, and the mass percentage of water in the water-based paint is 10% -30%;

Controlling the steel after film forming to enter a drying process for drying treatment to obtain dried steel;

Controlling the dried steel to enter a blowing process for blowing to obtain pretreated steel; wherein the wind speed of the blowing is more than or equal to 5m/s, and the blowing is hot wind at the temperature of 60-70 ℃.

2. The method of claim 1, wherein the method further comprises:

And if the surface temperature value is higher than a preset temperature value, closing the preheating process and controlling the steel to directly enter the spraying process.

3. the method according to claim 1 or 2, wherein the preset temperature value is 15 ℃.

4. The method of claim 1, wherein the thickness of the aqueous coating film is 10-15 μm.

5. The method of claim 4, wherein the aqueous coating film has a thickness of 10 μm.

6. The method of claim 1, wherein the temperature of said drying is 60-70 ℃ and the air speed of the unloaded cross section in the drying chamber in which said drying is performed is 0.15-0.3 m/s.

7. the method of claim 6, wherein the drying time is 2-2.5 min.

8. the method of claim 7, wherein the time of the air blast is 10-20 s.

9. The method of claim 8, wherein the blowing zone of the blowing process has a length of 2-3 m.

10. The method of claim 1, wherein the preheating process preheats the steel sheet using infrared rays.

Technical Field

The invention relates to the technical field of steel pretreatment, in particular to a steel pretreatment method.

Background

The steel shot blasting pretreatment line is a production line for steel blanking, shot blasting rust removal treatment before processing and protective anti-rust paint spraying, and is widely applied to the steel product processing and manufacturing industry. Protective rust inhibitive paints used in production lines are commonly referred to as shop primers or shop primers. The railway wagon steel pretreatment line is generally divided into a thin plate pretreatment line, a thick plate pretreatment line and a section steel pretreatment line, and the process flow generally comprises the following steps: steel material feeding → shot blasting → coating spraying → coating drying → steel material blanking.

the solvent-based paint is sprayed by using a traditional high-pressure airless spraying method, and the solvent-based paint can be dried after being sprayed and generally dried within 3min at the temperature of 60-70 ℃ because the organic solvent with high volatilization speed is adopted. But the problems of large VOC release amount, diluent waste, large personnel safety and health risks and the like exist in the using process.

the water-based paint replaces a diluent in the traditional paint with water, greatly reduces the discharge amount of toxic and harmful gases in the using process of the paint, has the advantages of environmental protection and safety, and is a paint which is advocated by the nation vigorously. But the water-based paint is completely used for replacing the traditional paint, and the technical problem of difficult drying exists when the water-based paint is used for the current rapid steel shot blasting pretreatment line.

Disclosure of Invention

In view of the above, the present invention has been made to provide a steel pretreatment method that overcomes or at least partially solves the above problems.

The application provides the following technical scheme through an embodiment of the application:

a steel pretreatment method is applied to a steel shot blasting pretreatment line, the steel shot blasting pretreatment line sequentially comprises a shot blasting process, a spraying process and a drying process, a preheating process is arranged between the shot blasting process and the spraying process, and an air blowing process is arranged after the drying process;

The method comprises the following steps:

After the shot blasting process is carried out, carrying out temperature detection on the surface of the steel to obtain a surface temperature value of the steel;

judging whether the surface temperature value is higher than a preset temperature value or not;

If not, starting the preheating process by air, and preheating the steel before the steel enters a paint spraying chamber to enable the surface temperature of the steel to be 15-40 ℃;

Controlling the steel to enter a spraying process; wherein, in the spraying process, based on an air spraying mode, the surface of the steel is sprayed by using a water-based paint, so that a uniform water-based paint film is formed on the surface of the steel, and the film-formed steel is obtained, wherein the thickness of the water-based paint film is 10-15 μm, and the mass percentage of water in the water-based paint is 10% -30%;

Controlling the steel after film forming to enter a drying process for drying treatment to obtain dried steel;

Controlling the dried steel to enter a blowing process for blowing to obtain pretreated steel; wherein the wind speed of the blowing is more than or equal to 5m/s, and the blowing is hot wind at the temperature of 60-70 ℃.

optionally, the method further includes:

And if the surface temperature value is higher than a preset temperature value, closing the preheating process and controlling the steel to directly enter the spraying process.

Optionally, the preset temperature value is 15 ℃.

optionally, the thickness of the water-based paint film is 10-15 μm.

Optionally, the thickness of the water-based paint film is 10 μm.

optionally, the drying temperature is 60-70 ℃, and the no-load section wind speed in the drying chamber where the drying is performed is 0.15-0.3 m/s.

Optionally, the drying time is 2-2.5 min.

Optionally, the time of the air blowing is 10-20 s.

optionally, the length of the blowing area of the blowing process is 2-3 m.

Optionally, the preheating process preheats the steel plate by using infrared rays.

one or more technical solutions provided in the embodiments of the present application have at least the following technical effects or advantages:

The method is applied to a steel shot blasting pretreatment line which sequentially comprises a shot blasting process, a spraying process and a drying process, and is characterized in that a preheating process is arranged between the shot blasting process and the spraying process, and an air blowing process is arranged after the drying process; the method comprises the following steps: after the shot blasting process is carried out, carrying out temperature detection on the surface of the steel to obtain a surface temperature value of the steel; judging whether the surface temperature value is higher than a preset temperature value or not; if not, starting the preheating process by air, and preheating the steel before the steel enters a paint spraying chamber to enable the surface temperature of the steel to be 15-40 ℃; controlling the steel to enter a spraying process; wherein, in the spraying process, based on an air spraying mode, the surface of the steel is sprayed by using a water-based paint, so that a uniform water-based paint film is formed on the surface of the steel, and the film-formed steel is obtained, wherein the thickness of the water-based paint film is 10-15 μm, and the mass percentage of water in the water-based paint is 10% -30%; controlling the steel after film forming to enter a drying process for drying treatment to obtain dried steel; controlling the dried steel to enter a blowing process for blowing to obtain pretreated steel; wherein the wind speed of the blowing is more than or equal to 5m/s, and the blowing is hot wind at the temperature of 60-70 ℃; because the surface of the steel is very cold in low-temperature weather, the temperature rise speed of the steel is very slow in the drying process, the drying speed of the water-based paint is greatly influenced, the surface temperature of the steel is detected before spraying, whether a preset temperature value is met or not is judged, and if the preset temperature value is not met, the adverse influence of the surface of the steel on the drying speed of the water-based paint can be eliminated by preheating the surface of the steel; the spraying flow of the air spraying method is small and adjustable, the atomization effect is good, when the air spraying method is used for spraying the water-based paint on a steel pretreatment line, the thickness of a dry film can be controlled to be about 10-15 mu m only by adding 10-30% of water, the film is formed uniformly, the drying time is faster as the water-based paint water adding proportion is smaller, and therefore, the drying speed of the water-based paint is greatly accelerated by the air spraying mode; the steel can be dried within 3min by adding the existing drying process and strong air blowing auxiliary drying, so that the dry water-based paint coating can be obtained after the steel shot blasting pretreatment line is pretreated by water-based paint at present rapidly (about 6-10 m/min).

Drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings needed to be used in the description of the embodiments are briefly introduced below, and it is obvious that the drawings in the following description are some embodiments of the present invention, and it is obvious for those skilled in the art to obtain other drawings based on the drawings without creative efforts.

FIG. 1 is a process layout of a steel pretreatment method according to an embodiment of the present invention;

FIG. 2 is a flow chart of a steel pretreatment method according to an embodiment of the present invention.

Detailed Description

The embodiment of the application provides a steel pretreatment method, and solves the technical problem that the existing rapid (about 6-10m/min) steel shot blasting pretreatment line is difficult to dry because the conventional coating is completely replaced by the water-based coating in the prior art.

in order to solve the technical problems, the general idea of the embodiment of the application is as follows:

a steel pretreatment method is applied to a steel shot blasting pretreatment line which sequentially comprises a shot blasting process, a spraying process and a drying process, and is characterized in that a preheating process is arranged between the shot blasting process and the spraying process, and an air blowing process is arranged after the drying process; the method comprises the following steps: after the shot blasting process is carried out, carrying out temperature detection on the surface of the steel to obtain a surface temperature value of the steel; judging whether the surface temperature value is higher than a preset temperature value or not; if not, starting the preheating process by air, and preheating the steel before the steel enters a paint spraying chamber to enable the surface temperature of the steel to be 15-40 ℃; controlling the steel to enter a spraying process; wherein, in the spraying process, based on an air spraying mode, the surface of the steel is sprayed by using a water-based paint, so that a uniform water-based paint film is formed on the surface of the steel, and the film-formed steel is obtained, wherein the thickness of the water-based paint film is 10-15 μm, and the mass percentage of water in the water-based paint is 10% -30%; controlling the steel after film forming to enter a drying process for drying treatment to obtain dried steel; controlling the dried steel to enter a blowing process for blowing to obtain pretreated steel; wherein the wind speed of the wind makes the wind speed of the steel surface tangent plane more than or equal to

5m/s, and the blowing is hot air at the temperature of 60-70 ℃.

In order to better understand the technical solution, the technical solution will be described in detail with reference to the drawings and the specific embodiments.

First, it is stated that the term "and/or" appearing herein is merely one type of associative relationship that describes an associated object, meaning that three types of relationships may exist, e.g., a and/or B may mean: a exists alone, A and B exist simultaneously, and B exists alone. In addition, the character "/" herein generally indicates that the former and latter related objects are in an "or" relationship.

also, the appearances of the phrases "in" and "out" in this document are not necessarily all referring to the same embodiment, but are to be construed broadly and encompass both forms.

the embodiment provides a steel pretreatment method, which is used for a steel shot blasting pretreatment line, and referring to fig. 1, the steel shot blasting pretreatment line sequentially comprises a traditional shot blasting process, a spraying process and a drying process, in addition, the invention is improved on the traditional pretreatment line, specifically, a preheating process is arranged between the shot blasting process and the spraying process, and an air blowing process is arranged after the drying process;

wherein, the preheating process can be opened and closed according to the requirement.

The method comprises the following steps:

After the shot blasting process is carried out, carrying out temperature detection on the surface of the steel to obtain a surface temperature value of the steel;

judging whether the surface temperature value is higher than a preset temperature value or not;

If not, starting the preheating process by air, and preheating the steel before the steel enters a paint spraying chamber to enable the surface temperature of the steel to be 15-40 ℃;

Controlling the steel to enter a spraying process, and spraying water-based paint on the surface of the steel by using an air spraying process to form a uniform water-based paint film on the surface of the steel to obtain the film-formed steel; wherein the thickness of the water-based paint film is 10-15 μm, and the mass percent of water in the water-based paint is 10% -30%;

controlling the film-formed steel plate to enter a drying process for drying to obtain a semi-dried steel material;

controlling the semi-dried steel to enter a blowing process for blowing to obtain pretreated steel; wherein the wind speed of the blowing is more than or equal to 5m/s, and the blowing is hot wind at the temperature of 60-70 ℃.

it should be noted that, after the steel is covered by the paint, the heat transfer efficiency of the surface of the steel is reduced, therefore, if the temperature of the steel is too low before the paint is sprayed, the steel is dried from the outer surface after the water-based paint is sprayed, which will result in that the temperature of the inner layer of the paint film close to the steel is low, which is not beneficial to the overall drying of the water-based paint film, and takes more time to dry; due to the change of the ambient temperature, it may cause the surface temperature of the steel to be higher or lower than a preset temperature value, for example, a temperature difference between winter and summer. Therefore, after shot blasting treatment of the steel, surface temperature detection is carried out, the detected temperature is judged, and if the surface temperature does not meet the requirement of a preset temperature value, a preheating process is started to preheat the steel before the steel enters a spraying process.

The preheating capacity ensures that the surface of the steel is preheated to 15-40 ℃ before painting under the condition of low-temperature weather in winter. The preheating method adopts an infrared heating mode, taking preheating from 0 ℃ to 15 ℃ on the surface of a steel plate with the thickness of 10mm as an example, and the installed electric power of the preheating process is not more than 70 kw. Other preheating modes meeting the preheating temperature requirement can be adopted instead. The process has the following functions: in low-temperature weather, the surface of the steel is very cold, and the temperature rise speed of the steel is very slow in the drying process, so that the drying speed of the water-based paint is greatly influenced. By preheating the surface of the steel, the adverse effect of the surface of the steel being too cold on the drying speed of the water-based paint in low-temperature weather can be eliminated; meanwhile, the phenomenon that the water-based paint is frozen after being sprayed when the temperature of the steel plate is close to 0 ℃ in winter can be avoided.

as an optional implementation, the method further comprises:

and if the surface temperature value is higher than a preset temperature value, closing the preheating process and controlling the steel to directly enter the spraying process.

It can be understood that when the ambient temperature is high, which results in the steel surface temperature being satisfactory, preheating is not required to save energy.

the preset temperature value can be set as required, and as an optional implementation mode, the preset temperature value is 15 ℃. Experiments prove that when the surface temperature of the steel plate is higher than 15 ℃, the subsequent drying requirement can be met.

The equipment for the air spraying process consists of a pneumatic diaphragm pump and an automatic air spray gun, wherein the pneumatic diaphragm pump is used for conveying the coating to the automatic air spray gun; the automatic air spray gun has the functions of regulating the flow of the coating, regulating the atomization effect, regulating the spraying sector and the like. The air spraying method has the characteristics of small and adjustable spraying flow and good atomization effect, when the air spraying method is used for spraying the water-based paint on the steel pretreatment line, the thickness of a dry film can be controlled to be about 10-15 mu m only by adding 10-30% of water (note that the welding quality problem of the post-process can be caused by the super-thick film), and the film is formed uniformly; while the traditional high-pressure airless spraying method can ensure that the thickness of the dry film is not more than 20 mu m by adding at least 100 percent of water. The smaller the water-based paint water-adding ratio, the faster the drying time will be. Therefore, the air spraying mode is changed to greatly accelerate the drying speed of the water-based paint, and the coating is very thin, thereby being beneficial to the subsequent welding of steel.

as an alternative embodiment, the thickness of the water-based paint film is controlled to be 10-15 μm, which is more beneficial to the drying of the film. Preferably, the thickness of the aqueous coating film is 10 μm.

As an optional implementation mode, the drying temperature is 60-70 ℃, and the no-load section wind speed in the drying chamber where the drying is carried out is 0.15-0.3 m/s. .

The water-based paint drying process can continue to use the existing solvent-based paint drying process and has the following basic conditions: the drying temperature can reach 60-70 ℃ at most, the air speed of an indoor no-load section is not less than 0.15m/s, the function of the waste gas exhaust fan is normal, and the volatile water vapor is ensured not to be accumulated continuously.

As an optional implementation mode, the drying time is 2-2.5min, the rapid operation of the pretreatment line is ensured, and the operation efficiency is ensured.

as an optional embodiment, the air blowing time is 10-20s, so that the rapid operation of the pretreatment line is ensured, and the operation efficiency is ensured.

As an optional implementation mode, the length of the blowing area of the blowing process is 2-3m, the action time of strong blowing is ensured, and the drying of the water-based paint is realized.

The following is a further explanation by way of specific examples.

Take a rail wagon steel shot blasting pretreatment line as an example.