What is the difference between welded pipes and galvanized pipes, and what electrodes are used for g

Welded steel pipe, also known as welded pipe, is a steel pipe made of steel plate or strip steel after being curled and formed, generally with a fixed length of 6 meters. The production process of welded steel pipe is simple, the production efficiency is high, the variety and specification are many, and the equipment investment is less, but the general strength is lower than that of seamless steel pipe.

Categorized by use.

It is divided into general welded pipes, galvanized welded pipes, oxygen-blown welded pipes, wire sleeves, metric welded pipes, idler pipes, deep well pump pipes, automotive pipes, transformer pipes, welded thin-walled pipes, welded special-shaped pipes, scaffolding pipes and spiral welded pipes.

General welded pipe: General welded pipe is used to transport low-pressure fluids. Manufactured with Q195A, Q215A, Q235A steel.

It can also be manufactured from other mild steels that are easy to weld. The steel pipe should be subjected to water pressure, bending, flattening and other experiments, and there are certain requirements for surface quality, usually the delivery length is 4-10m, and the delivery of fixed length (or double ruler) is often required. The specifications of the welded pipe are expressed by the nominal diameter (millimeters or inches) The nominal diameter is different from the actual one, and the welded pipe has two kinds of ordinary steel pipe and thickened steel pipe according to the specified wall thickness, and the steel pipe is divided into two kinds according to the form of the pipe end.

Galvanized steel pipe: In order to improve the corrosion resistance of steel pipes, galvanized general steel pipes (black pipes) are carried out. Galvanized steel pipes are divided into hot-dip galvanizing and electric steel zinc, with a thick hot-dip galvanized layer and low electrogalvanizing cost.

Peculiarity. The production process of longitudinal welded pipe is simple, the production efficiency is high, the cost is low, and the development is fast. The strength of spiral welded pipes is generally higher than that of longitudinal welded pipes, and welded pipes with larger diameters can be produced with narrower blanks, and welded pipes with different diameters can also be produced with blanks of the same width.

However, compared to the same length of straight seam pipe, the weld length is increased by 30 100%, and the production speed is lower.

Fields of application. The products are widely used in water engineering, petrochemical industry, chemical industry, electric power industry, agricultural irrigation, urban construction, and are one of the 20 key products developed in China.

For liquid transportation: water supply and drainage. For gas transportation: coal gas, steam, liquefied petroleum gas.

For structural purposes: as piling pipes, bridges; Pipes for wharves, roads, building structures, etc.

Galvanized pipes are welded with J422 electrode, an acid electrode, coating titanium-calcium type, J represents structural steel electrode, 42 is 42kg mm, and 2 is the tensile strength of the weld metal.

It is used for welding low-carbon steel structures and low-alloy steels with low strength grades, and is generally used for welding steel structures and ordinary carbon steel pipes.

The diameter of J422 electrode varies from to to, and it can be welded in all positions, AC and DC dual-purpose. It has excellent welding process performance and mechanical properties, stable arc, less spatter, easy slag removal, and beautiful weld forming.

Hot-dip galvanized pipes react the molten metal with the iron matrix to produce an alloy layer, so that the substrate and the coating are combined. Hot-dip galvanizing is to pickle the steel pipe first, in order to remove the iron oxide on the surface of the steel pipe, after pickling, it is cleaned in an aqueous solution of ammonium chloride or zinc chloride or ammonium chloride and zinc chloride mixed in an aqueous solution tank, and then sent to the hot-dip plating tank.

Hot-dip galvanizing has the advantages of uniform coating, strong adhesion and long service life. The hot-dip galvanized steel pipe matrix undergoes complex physical and chemical reactions with the molten plating solution to form a corrosion-resistant and compact zinc-iron alloy layer. The alloy layer is integrated with the pure zinc layer and the steel pipe matrix, so it has strong corrosion resistance.

Galvanized pipes are welded with J422 electrodes.

The galvanized pipe material is generally: Q215A; q215b；q235a；q235b。

J422 electrode can weld steel structures and ordinary carbon steel pipes.

q215a；q215b；q235a；The steel made of Q235B is ordinary mild steel, so it can be welded with J422 electrode.

Hello dear; I'm glad to be able to answer for you What welding rods are used for galvanized pipes and stainless steel pipes? : Galvanized pipes and stainless steel pipes can be welded together. It is to use J422 electrode.

Pay attention to ventilation during welding to prevent zinc vapor poisoning. Stainless steel pipes and galvanized pipes can be welded. From the point of view of specification interpretation, the purpose of using galvanized pipe is anti-corrosion, so the galvanized pipe and the welded connection are originally contradictory, and they can be welded, but after welding, the galvanized layer is destroyed, and it is best to install it in the way of threaded connection.

Welding in accordance with GB50235-2010 standard construction, galvanized welded pipe welding before welding the best to grind off the surface of the zinc or heat the galvanized to burn off the galvanized, so as to produce a large amount of gas is easy to appear pores. After the seal welding construction, 5% PT inspection should be done on each pipeline, and the seal welding joint should be galvanized twice.

It is possible to weld galvanized pipes, but after welding, the galvanized layer is destroyed, and it is best to install them in the way of threaded connections.

Galvanized pipeThere are two kinds of hot-dip galvanizing and electro-galvanizing, and the hot-dip galvanized layer is thick, and has the advantages of uniform coating, strong adhesion and long service life. The cost of electro-galvanizing is low, the surface is not very smooth, and its own corrosion resistance is much worse than that of hot-dip galvanized pipes.

Uses of galvanized pipes:Now it is mainly used for conveying gas and heating. After a few years of use, a large amount of rust and dirt is produced in the galvanized pipe, and the yellow water flowing out not only pollutes the sanitary ware, but also is mixed with bacteria that breed on the uneven inner wall; Rust causes high levels of heavy metals in water, which seriously endangers human health.

In the sixties and seventies, developed countries in the world began to develop new types of pipes, and successively banned galvanized pipes. China's Ministry of Construction and other four ministries and commissions also issued a document to explicitly prohibit galvanized pipes.

Production process of galvanized pipe:

Black parts inspection, hanging materials, degreasing, rinsing, pickling, cleaning, impregnation of plating agent, hot air drying, hot-dip galvanizing, internal and external blowing, cooling, passivation and rinsing, unloading, inspection, trimming, typing and marking, packaging, warehousing, transportation.

Galvanized strip Uncoiling, stretching, coiling tube, welding, scraping, passivating and rinsing, zinc supplementation, shaping, typing, marking, cutting, packing, drying, weighing.

In our daily life, many people have seen galvanized steel pipes, so can galvanized steel pipes be welded? Many people have questions about this problem, today I will tell you about the relevant content of galvanized steel pipe when it can be welded, I hope it can help you, if you are interested, you can follow to understand it.

1. Can galvanized steel pipes be welded?

Galvanized steel pipe can be welded, but it should be noted that after the galvanized steel pipe is welded, the galvanized layer after welding should be polished and smoothed, if not, it will affect the quality of galvanized steel pipe, and it is easy to cause blistering and oxidation of galvanized steel pipe.

Second, about the use of galvanized steel pipes.

1. We have all heard of galvanized steel pipes, commonly used galvanized steel pipes are generally used in gas heating iron pipes, galvanized steel pipes can also be used as water pipes, but after a few years of use, a large amount of rust will be produced in the pipe, in fact, we do not advocate the use of galvanized steel pipes as water pipes, because galvanized pipes are not suitable for long-term in a humid environment, which is easy to rust and corrode.

1. As early as the sixties and seventies, the state began to ban galvanized steel pipes one after another, but at present, galvanized steel pipes are still used in the cold water pipes of many new residential areas, and galvanized steel pipes are also used in the hot water pipes of many residential areas. Since 2000, China's Ministry of Construction has begun to ban galvanized steel pipes, and there are still many questions about why we still use galvanized steel pipes.

2. Galvanized steel pipes are easy to rust and corrode, especially when installed in places with water, which will cause a lot of bacteria, and may also endanger the health of the human body in serious cases.

The above is a summary of the relevant content and information about galvanized steel pipes that can be welded, I hope it can help you. If you have other questions, you can leave a message at the bottom of the platform, and we will solve the problem in time, and finally if you have any questions about home or home decoration, you can pay more attention to Qeeka Home.