Galvanized Strip Welded Pipe

Galvanized steel strip is processed by ordinary steel strip pickling, galvanizing, packaging and other processes. It is widely used because of its good anti-corrosion performance. It is mainly used to make metal products that are cold-worked and no longer galvanized. For example: metal products such as light steel keels, peach-shaped columns for guardrails, sinks, rolling doors, bridges, etc.

General civilian use. Processing household appliances, such as sinks, etc., can strengthen door panels, etc., or strengthen kitchen utensils, etc. achitechive. Light steel keels, roofs, ceilings, walls, water barriers, rain decks, rolling shutter doors, warehouse inner and outer panels, insulation pipe shells, etc. household appliances. Reinforcement and protection in household appliances such as refrigerators, washing machines, showers, and vacuum cleaners. Automobile industry. Cars, trucks, trailers, luggage carts, refrigerated truck parts, garage doors, wipers, fenders, fuel tanks, water tanks, etc. industrial sector. As the base material of stamping materials, it will be used in bicycles, digital products, armored cables and so on. other aspects. Equipment enclosures, electrical cabinets, instrument panels, office furniture, etc.

The post-treatment of galvanized steel strip includes three aspects, passivation, pre-phosphating and oiling. First of all, the passivation treatment of galvanized strip steel can improve the surface structure and gloss of the galvanized layer, improve the corrosion resistance and service life of the galvanized layer, and improve the bonding force between the coating and the base metal. The passivation treatment mainly adopts chromate passivation. Add some activators, such as fluoride, phosphoric acid or sulfuric acid, to the passivation solution to obtain a thicker chromate film after passivation. When there is fluoride in the passivation solution, the surface tension of the steel strip can be reduced, the film-forming reaction can be accelerated, and the chemical polishing effect can be increased to make the passivation film fine and bright.

The application effect of galvanized steel strip meets modern needs and is widely used as a building material today. Galvanized strip steel has the characteristics of no rust and corrosion resistance for many years. It can not be affected by the adverse external environment and always maintain its own performance and appearance. In the process of using galvanized steel strip, in order to improve its working efficiency and its own characteristics, the finished galvanized steel strip can be post-treated to make its performance even better.

Galvanized strip welded pipe has adjusted the production process of hot-dip galvanized pipe. First pickle the strip steel used for pipe making, in order to remove the iron oxide on the surface of the strip steel, after pickling, wash it in an aqueous solution of ammonium chloride or zinc chloride or a mixed aqueous solution of ammonium chloride and zinc chloride, and then into the hot-dip coating tank. It is then air-dried and made into tubes. The coating is uniform and bright, and the amount of galvanizing is very small, which is lower than the cost of producing hot-dip galvanized pipes.

Galvanized Steel Pipe Polishing Features

In order to prolong the service life of pipelines, pipeline anti-corrosion construction has become an indispensable process in the pipeline production process; with the continuous development and production of manufacturers, various types of anti-corrosion spiral steel pipes have appeared on the market.

The more common anti-corrosion types of spiral steel pipes on the market are: epoxy resin anti-corrosion, 3PE anti-corrosion, cement mortar anti-corrosion and epoxy asphalt anti-corrosion; different types of anti-corrosion steel pipes have different uses, and spiral welded steel pipes refer to those with seams on the surface. Steel pipes, which are welded with steel plates or steel plates to form round or square shapes;

Spiral steel pipe factory can be divided into arc welded pipe, high frequency resistance welded pipe, low frequency resistance welded pipe, gas welded pipe, furnace welded pipe, etc. according to different welding methods; according to the shape of the weld, it can be divided into straight seam welded pipe and spiral steel pipe, electric welded steel pipe for oil Drilling and machinery manufacturing; furnace welded pipes can be used as water gas pipes, large-diameter longitudinal welded pipes are used for high-pressure oil and gas transportation, spiral steel pipes are used for oil and gas transportation, pipe piles, bridge piers, etc.; compared with seamless steel pipes, welded steel pipes have lower cost and production higher efficiency.

Drinking water anti-corrosion steel pipe topcoat: It is composed of epoxy resin, rubber resin modification, harmless anti-rust pigments, fillers and additives, and has excellent chemical resistance and anti-microbial erosion.

Uses: It is used as primer for water supply pipelines, and topcoat is used for anti-corrosion coating on the inner wall of water supply pipelines; this kind of anti-corrosion is for drinking water pipeline projects, and it is non-polluting and harmless.

Maintenance measures:

1. The product should be stored in a cool, ventilated, dry place, away from fire and heat sources.

2. This product is a thick coat and can be applied in thick coats without sagging. Generally, after opening the barrel, it can be used without adding thinner.

3. After the paint is stored for a long time, there will be slight precipitation, so it should be stirred before use.

4. After the paint is ready, it should be cured for 20 minutes in summer and 1.5-2 hours in winter for construction. Usually use up within 8 hours, otherwise the viscosity will thicken and the application will not be easy.

5. The top coat can be applied after the primer surface is dry. This interval should not exceed two days at room temperature, otherwise the adhesion between the layers will be affected. The time interval between top coats should also allow the surface to dry. Interpenetrating network polymer is a new type of IPN series anti-corrosion coating researched and developed in the past twenty years. It is a copolymer of castor oil-based polyurethane and polysubstituted ethylene interpenetrating network polymer. During the mixing and curing process of paint, the former is rubber, and the latter’s plastic network penetrates into each other, penetrates and firmly adheres to the surface of the object to be coated, thus producing corrosion protection and decorative materials on the surface of the paint.

Advantages Of Plastic Coated Composite Pipe

The plastic-coated composite pipe is made of welded steel pipe as the base material, and is made by sandblasting chemical double pretreatment, preheating, plastic coating, curing, post-treatment and other processes. It has excellent comprehensive properties, strong mechanical corrosion resistance, good chemical stability and water resistance, and has functions such as corrosion resistance, pressure resistance, and antibacterial.

It is generally not restricted by the conveying medium, and the plastic coating has a strong bonding force with the steel. Coating material: Epoxy resin (EP) is suitable for the working environment. The steel pipe coating below 80 °C has high adhesion, high hardness, good impact resistance, and good chemical corrosion resistance.

The advantages of the product are high mechanical strength, suitable for harsh use environments; the inner and outer coatings can prevent metal oxidation, and have good chemical corrosion resistance. The coating has strong adhesion, high bonding strength and good impact resistance. Low surface roughness coefficient and friction coefficient, good adhesion to foreign matter; anti-aging, long service life.

Plastic-coated steel pipe is a new type of pipe material developed in recent years. The pipeline has successfully reduced the loss caused by pipeline corrosion and belongs to the green energy-saving pipeline. Its compression resistance, tensile resistance, corrosion resistance, and UV resistance are superior to other pipes. Therefore, plastic-coated steel pipes can be used in various engineering fields. According to different environments, plastic-coated steel pipes can exert different performance advantages.

The advantages of the product are high mechanical strength, suitable for harsh use environments; the inner and outer coatings can prevent metal oxidation, and have good chemical corrosion resistance. The coating has strong adhesion, high bonding strength and good impact resistance. Low surface roughness coefficient and friction coefficient, good adhesion to foreign matter; anti-aging, long service life.

Plastic-coated steel pipe is a new type of pipe material developed in recent years. The pipeline has successfully reduced the loss caused by pipeline corrosion and belongs to the green energy-saving pipeline. Its compression resistance, tensile resistance, corrosion resistance, and UV resistance are superior to other pipes. Therefore, plastic-coated steel pipes can be used in various engineering fields. According to different environments, plastic-coated steel pipes can exert different performance advantages.

How To Make 3PE Coating Steel Pipes

3PE Coating standard are ANSI/AWWA C104/A21.4 American National Standard for Cement-Mortar Lining for Ductile-Iron Pipe and Fittings for Water, ISO 21809 Petroleum and natural gas industries — External coatings for buried or submerged pipelines used in pipeline transportation systems, DIN 30670 Polyethylen coatings of steel pipes and fittings.

The normal bare pipe will be corroded in the severe environment and its lifetime will be reduced, making the construction and maintenance cost very high. But due to every layer of the 3PE coating system has its good performance, the 3PE coated pipe can protect the pipe in the severe environment and extend its lifetime to 30-50 years even longer. it can significantly reduces the construction and maintainance cost for the pipeline. At the same time, the 3PE coated pipe has favorable thermal insulation property, the thermal losses is just 25% of the traditional pipe, saving a lot of energy cost during operation. At last, the 3PE coated pipe can directly be laid underground or in the water even directly in the frozen earth because of its good anticorrosion property and impact resistance property in the low temperature, no need to construct ditch.

3PE Coating Steel Pipe has good thermal insulation performance, and the heat loss is only 25% of that of traditional pipes. Long-term operation can save a large amount of resources, significantly reduce energy costs, and has strong waterproof and corrosion resistance. With a pipe trench, it can be directly buried in the ground or water. The construction is simple and quick, the overall cost is low, and it has good corrosion resistance and impact resistance under low temperature conditions, and can be directly buried in frozen soil in a certain environment.

3PE Anti-corrosion Pipe Manufacturing Process

The base material of 3PE anti-corrosion steel pipe includes seamless steel pipe, spiral steel pipe and straight seam steel pipe. The three-layer polyethylene (3PE) anti-corrosion coating has been widely used in the oil pipeline industry due to its good corrosion resistance, water vapor resistance and mechanical properties. The anti-corrosion layer of 3PE anti-corrosion steel pipe is very important to the life of buried pipelines. Some pipelines of the same material will not corrode after being buried underground for decades, and some will leak within a few years. It is because they use different outer anti-corrosion layers.

3PE anti-corrosion generally consists of 3 layers of structure:

The first layer of epoxy powder (FBE>100um)

The second layer of adhesive (AD) 170~250um

The third layer of polyethylene (PE) 2.5 ~ 3.7mm

In actual operation, the three materials are mixed and integrated, and after processing, they are firmly combined with the steel pipe to form an excellent anti-corrosion layer. Its processing methods are generally divided into two types: winding type and round mold coating type.

3PE anti-corrosion steel pipe coating (three-layer polyethylene anti-corrosion coating) is a new anti-corrosion coating produced by cleverly combining the European 2PE anti-corrosion coating and the epoxy powder anti-corrosion steel coating (FBE) widely used in North America. Steel pipe coating. It has been recognized and used all over the world for more than ten years.

The coating of the 3PE anti-corrosion steel pipe is epoxy powder anti-corrosion coating that is in contact with the bottom layer and the steel pipe surface, and the middle layer is a copolymerized adhesive with branched functional groups. The surface layer is high-density polyethylene anti-corrosion coating.

3pe anti-corrosion coating combines the high impermeability and high mechanical properties of epoxy resin and polyethylene materials. So far, it is recognized globally as the pipeline anti-corrosion coating with the best effect and performance, so it has been applied in many projects.

Tempering Temperature And Mechanical Properties Of Pipeline

According to API5L, GB/T9711.1 pipeline steel pipe performance requirements, according to the different tempering temperature, tempering can be divided into the following:

1. Low temperature tempering (150-250 degrees)

The microstructure obtained by low temperature tempering is tempered martensite. The purpose is to reduce the quenching stress and brittleness of the quenched steel on the premise of maintaining high hardness and high wear resistance, so as to avoid cracking or premature damage during use. It is mainly used for a variety of high carbon cutting tools, measuring tools, API5L,GB/T9711.1 pipeline steel pipe, rolling bearing and carburizing parts, temper hardness is generally HRC58-64.

2.  Moderate tempering (250-500 degrees)

The microstructure obtained by moderate tempering is tempered troxite. The aim is to obtain high yield strength, elastic limit and high toughness. Therefore, it is mainly used for all kinds of API5L,GB/T9711.1 pipeline steel pipe and hot working die treatment, tempered hardness is generally HRC35-50.

3.  High temperature tempering (500-650 degrees)

The microstructure obtained by high temperature tempering is tempered soxite. It is customary to combine quenching and tempering heat treatment called tempering treatment, its purpose is to obtain strength, hardness and plasticity, toughness are better comprehensive mechanical properties. Therefore, it is widely used in automobile, API 5L, GB/T9711.1 pipeline steel pipe, machine tools and other important structural parts, such as connecting rod, bolt, gear and shaft. The hardness after tempering is generally HB200-330.

Mechanical Properties:

The Material Of The Pipeline

Application: Used for gas, water and oil transportation in petroleum and natural gas industry

API SPEC 5L-2011 (Pipeline Specification), developed and published by the American Petroleum Institute, is used worldwide. The main material of the tube is L245, L290, L360, L415, L480, GR.B, X42, X46, X56, X65, X70, X80, X100 and other steel grade.

Stainless Steel Pipe Welding Matters

1. It is generally suitable for welding of thin steel pipe below 6mm, with the characteristics of beautiful and elegant weld molding and small welding deformation.
2. The maintenance gas is argon with the purity of 99.99%. When the welding current is 50-50A, the argon flow rate is 8-10L/min, and when the current is 50-250A, the argon flow rate is 2-5L/min.
3. The length of the tungsten pole protruding from the gas nozzle is 4-5mm, 2-3mm in the place of poor masking such as fillet welding, 5-6mm in the place of deep grooving, and the interval from the nozzle to the operation generally does not cross 5mm.
4. In order to prevent the appearance of welding pores, it is necessary to clean up the welding parts if there is rust and oil.
5 Welding arc length, welding shallow steel, with 2-4mm is the best, and stainless steel welding, with 3mm is the best, too long maintenance results are not good.
6. When docking the bottom, in order to prevent the back of the bottom weld passage from being oxidized, the back also needs to implement gas maintenance.
7. In order to maintain the welding pool well with argon and facilitate the welding operation, an Angle of 80-85° should be connected between the middle line of the tungsten pole and the workpiece at the welding place, and the general Angle between the filler wire and the workpiece should be as small as possible, generally 0°.
8. Windproof and ventilation. In windy places, please choose the method of retaining the net, and in the room, the appropriate ventilation method should be selected.

Classification Of Galvanized Pipes

Galvanized pipe, also known as galvanized steel pipe, is divided into hot dip galvanized and electric galvanized. Hot dip galvanizing layer thick, uniform coating, strong adhesion, long service life. Electroplating cost is low, the surface is not smooth, corrosion resistance than hot dip galvanized pipe is poor.
Galvanized steel tube: hot dip galvanized steel tube steel tube substrate and molten plating solution composite physical, chemical reaction, forming a dense zinc iron alloy layer corrosion resistant structure. The alloy layer is integrated with the pure zinc layer and the steel tube substrate. Therefore, its corrosion resistance is strong.
Galvanized steel pipe: The zinc layer of cold galvanized steel pipe is an electric coating, and the zinc layer is separated from the steel pipe substrate. The zinc layer is very thin, and the zinc layer is simply attached to the steel tube substrate, which is easy to fall off. As a result, its corrosion resistance is poor. In new homes, the use of cold galvanized steel pipes as water supply is prohibited

Introduction To Vessels Steel Plate

In fact, the vessels is a big category among many steel plates, which has very special composition and many excellent properties. At present, this kind of vessels plate is mainly used to make pressure vessels in the market. For different situations and different uses, the corresponding materials to be made are also different.

This kind of device has a relatively large number of brand names in the current market, and its application scope corresponding to different delivery states is also different. In the following small series, users will be specifically introduced about the vessels plate.

Introduction to the use of the vessels

vessels plate is now widely used in petroleum, chemical industry, power stations and boilers, etc. It is used to manufacture reactors, heat exchangers, separators, spherical tanks, oil and gas tanks, liquefied gas tanks and nuclear reactor pressure shells, etc. In addition, this material is also used to manufacture boiler drums, liquefied oil and gas cylinders, high-pressure water pipes of hydropower stations, spiral cases of water turbines and other equipment or components. Moreover, this material has a very broad market at home and abroad.

Introduction of delivery status of vessels

There are four main delivery states of plates, namely quenching, normalizing, annealing and tempering. Moreover, the main application scope of each delivery state is also different.

Main application scope of normalizing

Compared with low carbon steel, the hardness of vessels plate after normalizing is higher than that after annealing, and its toughness is relatively good.

Can be used with medium carbon steel.

Used for tool steel, carburized steel and bearing steel.

Used for steel castings, normalizing, it has a good refining effect on the microstructure of steel materials.

It is used for large forgings and nodular cast iron, which can improve its hardness, strength and wear resistance.

Characteristics of the plate after tempering

1. After tempering, the structural stability of the vessels plate can be improved, so that the size and performance of the workpiece can be kept in a very good state.

2. After tempering, for the product made of vessels plate, it can also eliminate the internal stress in the container plate, thus changing the service performance of the device.

3. The mechanical properties of the vessels plate can be well adjusted, so as to meet the requirements of application in various fields.

Plate is a kind of important steel plate used for manufacturing various boilers and their accessories, and it is also the most widely used and used special steel plate for pressure vessels in China at present.