Galvanized strip pipe is a kind of steel pipe made from cold-rolled galvanized strip steel, which is formed by cold bending and then welded by high frequency. It is characterized by strong protective effect and strong corrosion resistance. Let's introduce the production process of galvanized steel pipe.

1. Feeding process

The first process is the feeding process, the galvanized strip is fixed on the material rack; Convenient to put the strip steel into the storage box for the unit to use, our company spent a lot of money to build MES system, above the production information, production information, warehousing information. Realize paperless office, information sinks to every process, so that employees have first-hand information in real time. Raw materials enter the storage box to ensure continuous operation of the unit.

2. The second process of forming welding zinc supplement process is forming welding zinc supplement process. The strip steel is transformed into steel pipe by forming roll. Next up is the welding and scab removal process. We adopt the more advanced ERW welding process in China, the main principle is to use the skin effect and proximity effect of high-frequency welding, so that the surface metal of the weldment to be welded can be heated quickly to achieve welding. Its advantage is that the heat affected zone of the weld is small, the heating speed is fast, and the welding speed and quality are improved. This process plays a key role in the corrosion resistance of the weld of the steel pipe. We use 2 zinc wires with a diameter of 1.5mm and a zinc content of 99.99% to replenish the weld with zinc to ensure the corrosion resistance of the weld to the maximum extent. With this process, we can ensure that the weld is completely invisible on the outside of the steel pipe, and the corrosion resistance of the weld after our treatment is completely consistent with the other parts of the steel pipe.

3. Set the straight process

The third process is the sizing and straightening process, the adjustment of the welded billet shaping roller can ensure the outer diameter accuracy of the steel pipe, or the round pipe is changed into a square tube, and the straightening roller can ensure the straightness of the steel pipe.

4. Flying saw sawing process

The fourth process is the sawing process, when the length meets the parameter requirements, the flying saw will automatically cut, we use the latest generation of high-speed flying saw, cutting speed can reach 150 meters -180 meters/minute; To ensure that the pipe end interface is more flat to the maximum extent, more convenient for later end customers to use.

5. The fifth process of weld inspection process is the weld inspection process. Our product quality control is quite strict. The staff will single out the unqualified products, and we will downgrade the unqualified products.

6. Inkjet marking process

The sixth process is the inkjet printing process, our company uses France's more advanced inkjet machine, which is characterized by clear inkjet, not easy to fade. Our product brand name, slogan and product implementation standards are printed on each steel pipe to ensure that each steel pipe can be reflected.

7. Passivation process

The seventh process is passivation process, in the passivation process we have our own invention patent - galvanized pipe passivation liquid automatic spraying system, to ensure that the passivation liquid 360° uniform adhesion, high passivation efficiency, beautiful outside. Can meet the salt spray test for at least 18 hours, no corrosion. Exclusive process, anticorrosive and durable.

8. The eighth process of automatic blanking packaging process is the automatic blanking system of steel pipe, which is the highest application of our automation and intelligent program. The robot arm is turned over to the conveyor chain, and the protected conveyor chain transmits the steel pipe to the material of the stepper machine for step loading. The automatic sensor is used to identify the position of the steel pipe, the system collects signals, controls the reciprocating transport of the steel pipe by the stepper, and aligns the steel pipe by the roller table. The automatic coding machine automatically identifies the number of steel pipes according to the input instructions, and uses the electromagnetic device to pick up, translate, place and reset the steel pipes in one go to realize the automatic place. The whole process does not require manual operation, and workers only need to monitor the system to work correctly.

9. Automatic weighing and labeling process after packaging, the steel pipe is stepped to the weighing machine by the conveyor chain, and automatically lifted and weighed, automatically labeled, automatically pasted, and automatically discharged from the warehouse in one go. Greatly reduce the labor intensity of employees, but also to ensure that the weight of each steel pipe is accurate, and each steel pipe information (product specifications, production date, raw material manufacturers, production teams, each piece of weight) are given an independent two-dimensional code, easy to trace.

Galvanized pipe (SC) is a common steel pipe material, which is treated by hot-dip galvanizing technology in the manufacturing process. So, what does galvanized pipe SC mean?

1. Basic concept of galvanized pipe

Galvanized pipe refers to the pipe immersed in molten zinc liquid, after a series of chemical reactions and physical changes, so that the surface of the pipe formed a layer of zinc-iron alloy coating of the pipe. This galvanized treatment can effectively prevent the corrosion of the surface of the steel pipe and extend the service life of the steel pipe.

2. Meaning of galvanized pipe SC

The "SC" in galvanized pipe SC stands for "Standard Class". In the production and sales process of galvanized pipes, in order to facilitate the distinction between different standards and specifications, some code names or abbreviations are often used to indicate.

3. Standard grade of galvanized pipe SC

The standard grade of galvanized pipe is differentiated according to its manufacturing process and material and other factors. Generally, galvanized pipe SC is divided into SC1, SC2 and SC3 grades, which correspond to different surface treatment quality and corrosion resistance.

SC1: The surface treatment quality is higher, the galvanized layer is thicker, and the corrosion resistance is better. Suitable for demanding engineering projects, such as chemical, oil, natural gas and other fields.

SC2: Moderate surface treatment quality, moderate galvanized layer, good corrosion resistance. Suitable for general engineering projects, such as buildings, Bridges, roads and other fields.

SC3: The surface treatment quality is low, the galvanized layer is thin, and the corrosion resistance is general. It is suitable for some projects with low requirements for galvanized layer, such as agriculture, furniture and other fields.

4. Application field of galvanized pipe SC

Galvanized pipes are widely used in various fields, including construction, industry, agriculture and so on. It has the following main features:

- Good corrosion resistance: the galvanized layer can effectively prevent the surface of the steel pipe from oxidation and corrosion, and improve the service life of the steel pipe.

- Good welding performance: the galvanized pipe can maintain good welding performance during the welding process, and it is not easy to have weld cracking and other problems.

- Wide applicability: Galvanized pipe can be applied to different engineering projects and environmental conditions, with strong adaptability.

- Low cost, easy processing: Galvanized pipe manufacturing cost is relatively low, processing and installation is convenient, suitable for large-scale production and use.

In the construction field, galvanized pipes are often used in the construction of water supply pipes, drainage pipes, HVAC pipes and other systems. In the industrial field, galvanized pipes are often used for conveying gas, liquid and other media pipeline systems. In the field of agriculture, galvanized pipes are often used to build greenhouses and build livestock facilities.

Hot-plated pipe and ordinary galvanized pipe, although the two seem similar, but there are significant differences. These differences are mainly reflected in their production processes, performance characteristics and application fields.

First of all, from the point of view of the production process, the hot-plated tube is produced by the hot-dip galvanizing process. In this process, the steel pipe first goes through a pre-treatment process such as pickling and cleaning, and then is immersed in the molten zinc liquid, and is removed after a period of time to form a zinc-iron alloy layer. The ordinary galvanized pipe is produced by electroplating process, that is, zinc ions are deposited on the surface of the steel pipe through the action of current to form a zinc layer. These two different production processes make the performance of hot-plated pipe and ordinary galvanized pipe different.

In terms of performance characteristics, because of the hot dip galvanizing process, the zinc-iron alloy layer on the surface of the hot plated tube is closely combined with the steel tube matrix, which has good corrosion resistance and can effectively prevent the corrosion of the steel tube during use. The zinc layer of ordinary galvanized pipe is relatively thin, the binding force with the steel pipe matrix is weak, and the zinc layer is easy to fall off during use, which affects its anti-corrosion performance.

In addition, in the field of application, because of its excellent anti-corrosion performance and long service life, hot plated tubes are widely used in various fields such as construction, transportation, petroleum, chemical industry, especially those with high anti-corrosion performance requirements. The ordinary galvanized pipe is mainly used for some occasions with low anti-corrosion performance requirements, such as some temporary buildings or facilities.

In general, hot plated pipe and ordinary galvanized pipe are a kind of galvanized steel pipe, but due to the different production process and performance characteristics, they are also different in the application field. When choosing the use, we need to choose the appropriate type of steel pipe according to the specific use environment and needs.

Can be hot galvanized or cold galvanized

Galvanized pipe can be hot galvanized or cold galvanized.

Hot-dip galvanized pipe is the steel pipe immersed in high temperature molten zinc liquid to form a layer of solid zinc-iron alloy coating, which has high adhesion and can provide excellent corrosion resistance, while cold galvanized pipe is coated with a thin layer of zinc on the surface of the steel pipe by electrochemical method, the coating thickness is thin, and the corrosion resistance is relatively poor.

The coating of hot-dip galvanized pipe is thicker, generally reaching 50 to 120 microns, which can effectively block the erosion of external oxygen and water and provide a longer protective effect, while the coating of cold galvanized pipe is relatively thin, generally between 5 and 30 microns.

Galvanized pipe as a widely used material, its production and use in the process will indeed encounter some technical problems. Fortunately, as technology advances, there are solutions to these problems. At the same time, due to fluctuations in market demand, the price of galvanized pipes will also be affected to a certain extent, which is a common phenomenon in the market economy.

In the production process, steel leakage defect is a common problem. In order to reduce production costs and improve the strength of steel, manufacturers often add a higher proportion of silicon to steel-based materials. However, if the amount of silicon is too much, it will lead to an increase in the surface tension of the steel, which reduces the wetting ability of the steel plate to the zinc liquid and affects the galvanizing effect. In addition, silicon is easy to react with oxygen to produce silica at high temperatures, and if these acidic substances cannot be effectively removed, steel leakage defects will be formed during the galvanizing process.

In order to solve this problem, continuous hot-dip galvanizing process of hot-rolled steel strip without pickling can be adopted. This process is characterized by feeding the steel strip directly into the reduction furnace without going through the pickling step, and increasing the volume fraction of hydrogen to more than 20% to reduce the possibility of oxidation. At the same time, in the process of hot dip galvanizing, the adhesion of the coating can be significantly improved by forming Fe-Al-Zn alloy layer on the surface of the steel strip, so as to effectively eliminate steel leakage defects. These countermeasures are very worthy of reference for galvanized pipe manufacturers.

Another problem is the loss of the zinc layer, which is usually caused by the low heating value of the gas in the pentoxide furnace or the oxidation atmosphere caused by pressure fluctuations. In order to solve this problem, several countermeasures can be taken:

a. Choose a gas burner with better combustion performance to ensure that the pressure of air and gas is stable in an appropriate range;

b. Control the fluctuation range of gas heating value to ensure that its fluctuation does not exceed ±5%;

c. In the open flame heating, the temperature of the forge should be maintained above 1000℃;

d. If the forging furnace without burner preheating is used, its temperature should be maintained above 800℃;

e. The temperature of the strip steel when leaving the pentoxide furnace should be controlled below 650℃.

Through these measures, the zinc layer can be effectively prevented from falling off and the quality of galvanized pipe can be guaranteed. In short, although galvanized pipes may encounter some problems in the production and use of the process, but through scientific methods and technological innovation, these problems can be solved. At the same time, producers also need to pay close attention to market dynamics in order to better cope with the challenges posed by price fluctuations.

First, the difference between galvanized pipe and steel pipe

Galvanized pipe is a kind of pipe that covers the surface of ordinary steel pipe with zinc layer, which is characterized by good corrosion resistance and smooth surface. The steel pipe is not galvanized, and its surface anti-corrosion ability is weak and easy to be corroded.

Second, the durability of galvanized pipe and steel pipe comparison

1. Corrosion resistance

Because the galvanized pipe has been galvanized, it has good corrosion resistance and long service life; The untreated steel pipe is easy to be corroded and has a short service life.

2. Carrying capacity

The bearing capacity of the steel pipe is stronger than that of the galvanized pipe, because the surface of the steel pipe has no galvanized layer, and the material is relatively stronger.

3. Use environment

In wet environments, galvanized pipes are more durable than steel pipes because the zinc layer prevents moisture from entering the pipe, thereby protecting the pipe from damage.

In a dry environment, the life of the steel pipe is longer, especially in the absence of acid and alkali corrosion, and the service life is longer.

Third, how to choose galvanized pipe and steel pipe

1. Select according to the use environment

In humid environment, it is recommended to choose galvanized pipe; In a dry environment, steel pipe is recommended.

2. Select based on load requirements

If you need to carry a larger weight of items, it is recommended to use steel pipe, because it has a stronger load capacity.

3. Select based on the actual situation

Galvanized pipe is a material that is often used in daily life. So, is this material made of iron or steel?

First of all, we need to make it clear that galvanized pipes are actually made of steel. This pipe is also known as galvanized steel pipe, which can be divided into two types: hot dip galvanized and electric galvanized. If it is a hot-dip galvanized pipe, the galvanized layer will be thick and uniform, so its service life will be longer. However, if it is electrically galvanized galvanized pipe, although its cost is lower, its surface is not particularly smooth, and its corrosion resistance is not as good as the former. Therefore, we recommend to try to choose hot-dip galvanized galvanized pipe.

Secondly, there are many galvanized pipe manufacturers sold on the market, and we need to understand the quality of the products when buying, so as to ensure that the quality is more guaranteed.

Next, let's talk about the difference between galvanized pipes and stainless steel pipes.

First of all, the meanings of the two are completely different. Galvanized pipe is made by welding, there are mainly two types of hot dip galvanized and electric galvanized. The stainless steel pipe is actually a long round steel.

Secondly, the scope of application of the two materials is also different. Galvanized pipe can be widely used in construction, chemical, electric power, automobile, bridge and other industries. The stainless steel pipe is mainly suitable for chemical, food, petroleum and other industries, in addition, it can also be used for the manufacture of some parts.

Finally, we need to pay attention to the following points when using galvanized pipes:

In the process of use, do not use sharp objects to knock on the surface, otherwise it may cause cracks. At the same time, try to avoid letting the material come into contact with easily corroded products to prevent corrosion.

When dealing with the gap between the pipes, the sleeve can be installed, generally the thickness of the sleeve is greater than 10 mm, and the gap is filled with insulation material.