How to identify fake and shoddy seamless steel pipes, will you check if you buy seamless steel pipes

You can start from the appearance and geometric size, the surface of the pipe made by the general large unit is relatively smooth, the size tolerance is relatively small, and the opposite is true. If you want to know a little deeper, you can do a spectroscopy and do an impact test.

Inspect the material to know if it's fake.

Legal analysis: No, as long as it is not used for the production of dangerous goods, Li Zhenkai will not check. However, many criminals often carry out illegal and criminal acts under the guise of buying high-pressure oil pipes.

Legal basis: Article 125 of the Criminal Law of the People's Republic of China [Crimes of illegally manufacturing, trading, transporting, mailing, or storing firearms, ammunition, and materials, and crimes of illegally manufacturing, trading, transporting, transporting, or storing dangerous substances] Whoever illegally manufactures, trades, transports, mails, or stores firearms, ammunition, or ** items shall be sentenced to fixed-term imprisonment of not less than three years but not more than ten years; where the circumstances are serious, the sentence is 10 or more years imprisonment, life imprisonment, or death. Where poisonous, radioactive, infectious disease pathogens and other substances are illegally manufactured, traded, transported, or stored, endangering public safety, punishment is to be given in accordance with the limits of the preceding paragraph.

Where a unit commits the crimes in the preceding two paragraphs, the unit is to be fined, and the directly responsible managers and other directly responsible personnel are to be punished in accordance with the limits provided for in the first paragraph.

Seamless steel pipes are not illegal items, they are an important building material used to transport fluids (such as water, gas, oil, etc.) or for structural support.

You may have heard about illegal situations, which may be related to the use of seamless steel pipes, such as illegal or criminal activities such as the use of basmosis in the manufacture of controlled knives, illegal theft of gas, etc. In addition, if there are illegal or illegal acts in the production, sale or use of seamless steel pipes, they will also be regarded as illegal acts.

Therefore, seamless steel pipes are not illegal items per se, but their use and management must be carried out within the legal framework to ensure safety and legality.

How to identify:

1. The seam pipe can find out the position of the original scraping burr of the welded pipe (generally ERW welding) by feeling (hand touch or observation), if it is not handled well, it can basically be directly recognized, and there is no welding trace is the seamless pipe.

2. Quickly corrode directly with newly prepared nitric acid alcohol, and a white thin line will come out to treat the weld, which can be identified.

Seamless pipes or seamed pipes.

The seamed steel pipe is curled into a circle with a steel plate and then welded together, so there will be a very clear weld on it, and the seamless steel pipe is directly processed by perforation or hot rolling and other processes with round steel. So there is no weld on the outer surface.

If you take a closer look, you will see that there is a weld that is a welded pipe, and there is no weld that is seamless [Liaocheng Jinhuiyuan Steel Pipe].

The common way is to:

1.As a rule of thumb, there are generally seam tubes without thick walls.

2.Look at it with the naked eye, see if there is a welding bar on the inner wall of the tube, and if there is no welding bar, then see if there is a trace of polishing;

The Utilization of Equipment Act is:

Doing flaw detection assays is the most effective way to do flaw detection assays.

There is a so-called fluid tube on the market, which is actually a processed executive.

There is a so-called fluid pipe on the market, which is actually a high-frequency welded pipe that has been treated, and the treatment method is to use special equipment to cut off or grind off the original weld, and there is also a hot rolling of the welded pipe.

1) All those that are cut off or ground off will leave traces, some are still obvious, and sometimes it is more obvious after removing rust with tools;

2) Let's take a closer look at the following, 20 steel and Q235 have different rusts due to their different materials;

3) Due to the fear of taking responsibility, the manufacturers of this kind of pipe dare not say that they are fluid pipes on their quality certificates and dare not say that they are seamless steel pipes for fluids;

4) Merchants who sell this kind of pipe will generally require settlement by theoretical weight, and we all know that the real domestic seamless steel pipes are beyond the standard thickness, generally weighed;

5) There is also flaw detection and composition inspection, both of which have limitations, because flaw detection is difficult to distinguish the hot-rolled welded pipe;

The appearance can be seen, there is a seam is a weld in the tube.

1. Seamless steel pipe is a kind of long steel with a hollow section and no joints around it.

2. Seamless steel pipe testing includes performance testing, chemical composition testing, physical property testing, specification and appearance quality, packaging, etc.

3. There are testing standards for seamless steel pipes.

Seamless Tubes for Structural Structures (GB T8162-2008), Seamless Tubes for Fluid Transportation(GB T8163-2008), Seamless Tubes for Low and Medium Pressure Boilers (GB3087-2008), Seamless Tubes for High Pressure Boilers (GB5310-2008), Seamless Tubes for Fertilizer Equipment (GB6479-2000), Seamless Tubes for Petroleum Cracking (GB9948-2006), Steel Pipes for Geological Drilling (YB235-70).

Seamless pipe for diamond core drilling (GB3423-82) and oil drilling pipe (YB528-65).

Carbon steel seamless pipe for ships (GB5312-85).

Seamless pipe for automobile half-shaft casing (GB3088-82), high-pressure oil pipe for diesel engine (GB3093-86).

Precision Inner Diameter Seamless Pipe for Hydraulic and Pneumatic Cylinder Barrel (GB8713-88) Cold Drawn or Cold Rolled Precision Seamless Pipe (GB3639-83) Stainless Steel Seamless Pipe for Structure (GB T14975-2002) Stainless Steel Seamless Pipe for Fluid Transportation (GB T14976-2002) 4. For seamless steel pipe inspection operation steps, you can refer to the seamless steel pipe inspector's manual, ** as follows.

Teach you six tricks how to distinguish between thick-walled seamless pipes and bad In the application of seamless pipes, some industries have a lot of requirements for this kind of pipe, so how should we distinguish the good and bad of thick-walled seamless pipes? Let me teach you a few tricks.

1. The composition of high-quality thick-walled seamless pipe is uniform, the tonnage of the cold shear machine is high, and the end face of the cutting head is smooth and neat, while the end face of the cutting head is often lost due to the poor material, that is, uneven and uneven, and there is no metallic luster. And due to the small number of cutting heads in the products of fake and shoddy material manufacturers, big ears will appear at the head and tail.

2. The shoddy thick-walled seamless pipe has no metallic luster, and is light red or similar to the color of pig iron, for two reasons, its blank is that the temperature of adobe pseudo and inferior material rolling is not standard, and their steel temperature is visually measured, so that it cannot be rolled according to the specified austenite area, and the performance of the thick-walled seamless pipe will naturally not be up to standard.

3. The material of the fake and inferior thick-walled seamless pipe contains many impurities, the density of the steel is small, and the size is out of tolerance, so it can be weighed and checked without vernier calipers.

4. The cross-section of the fake and inferior thick-walled seamless pipe is oval, because the manufacturer in order to save materials, the amount of pressure in the first two lanes of the finished roll is too large, and the strength of this rebar is greatly reduced, and it does not meet the standard of rebar dimensions.

5. The surface of the shoddy thick-walled seamless pipe is prone to scarring. There are two reasons: the material of shoddy thick-walled seamless pipes is uneven and there are many impurities. The guide and sanitation equipment of the fake and shoddy material manufacturers is simple, and it is easy to stick to the steel, and these impurities are easy to produce scarring after biting the roll.

6. The surface of the fake and inferior material is prone to cracks, because its blank is adobe, and the adobe has many pores, and the adobe is subject to thermal stress in the process of cooling, resulting in cracks, and there are cracks after rolling.

The above are the six ways we can distinguish the good and bad seamless management in production and life. Only by knowing and understanding these can we choose a good seamless pipe manufacturer, a good and seamless pipe, and a reasonable pipe.

I'll send you your answer right away.

Dear, good morning, to identify the advantages and disadvantages of steel pipe fasteners, first of all, we can use the naked eye**, the tooth edge of the pipe fittings should be sharp, the tooth distance is uniform and bright. 2. You can also touch the tooth edge with your hands, which should be smooth and the processing depth is standardized. 3. The core of the stainless steel clamping pipe fittings is evenly walled, and the flow parts are unblocked.

4. The pipe fittings are all manufactured after strict mechanical treatment, so the surface should be free of inclusions. 5. Low carbon content, corrosion resistance, oxidation resistance, strong toughness and strong pressure resistance.

1.First of all, you must choose Masteel fasteners, Masteel is also known as "black-hearted forgable cast iron", in order to make high-quality Masteel fasteners, you must choose high-quality ingredients (pig iron, wrought iron, scrap steel, ferrosilicon, ferromanganese, coke, etc.) in the selection of materials.

2.It is best to choose the mechanism shape of the fastener production, because the fastener produced by the mechanism shape has a small error in weight, uniform texture, exquisite and beautiful appearance, and can also engrave its own brand, so that it can not be distinguished from the fasteners of other foundries, especially for the rental station has played a great help, so that you will not worry that your fasteners will be confused with others.

3.Fasteners must be in strict accordance with the requirements in the production process, such as sand mixing, modeling, sand removal, heat treatment, drilling, pressure testing, dipping, assembly and other processes step by step, after these processes the staff must carefully observe every small detail, even if it is a small screw, but also pay attention to whether it is qualified.

4.Then see if the paint used in the fastener is good, because good paint is not easy to fade and slag, so its corrosion resistance and rust resistance are very strong, and the service life will be very long.

5.Before packing, put the factory date into the bag, and the fasteners of the packaging bag should be weighed to check whether the pure gold is sufficient.

Hello, glad to answer for you.

1.When the steel is 304 stainless steel, the 304 corresponding test solution is used for testing, and if it is true, the corresponding test result will appear. This is a nose-specific test method that can be distinguished between different grades of steel.

2.The use of copper sulfate solution, drip solution on the product, if there is no change, it belongs to **, otherwise it is inferior.

The above is to introduce you to the two methods of identifying the authenticity of stainless steel, the testing process is both scientific and accurate, and you can quickly make a judgment.

Stainless steel pipes play an extremely important role in our daily life, but we are still a little unfamiliar with this "familiar friend", what elements do they have?

Hardness, toughness, corrosiveness, the proportion of different elements determines the performance difference of stainless steel pipes, and a variety of steel pipes with different hardness and corrosion resistance will be formed.

1.Carbon: It can be said that carbon is an indispensable raw material in pipes, as important as human blood. High carbon means strong resistance, sufficient stiffness, and not easy to deform; Of course, the corrosion performance is reduced on the contrary.

2.Manganese: It can improve high temperature resistance and wear resistance, and high-strength alloy steel contains a large amount of manganese, which increases its strength.

3.Nickel: Ensures the stability of stainless steel, but because nickel is scarce, other elements should be used instead.

4.Aluminum: Refine the crystal structure of steel, improve material toughness, oxidation resistance, and durability.

5.Phosphorus: This is different from the above elements, phosphorus is harmful to stainless steel pipes, making their performance worse and inferior, so the industry requires that the phosphorus content should be less than.

The stainless steel pipe manufacturers with real standards and thickness are directly hitting the stainless steel pipe specifications, thickness, materials, brands and other information on the pipe body.

The easiest way to do this is to look at the appearance. If there is a seamed steel pipe, there will be a welded straight line, or traces of surface polishing. There is also straightness, uneven thickness, and if it doesn't work, you can only do a test.

Some seamed steel pipes are annealed to the weld seam, which eliminates the residual stress of the weld, makes the weld comparable to the base metal, and its bearing range is basically equivalent to that of the seamless pipe.

And some seamless steel pipes that are drawn or rolled with cores after the overall heating of seamed steel pipes are mainly small-gauge pipes, which are only seamless pipes in terms of appearance, and their essence is not very good, and the identification method is to do pressure test.

The "Eddy Current Testing and Identification Technology of Seamed and Seamless Stainless Steel Pipes" published in the journal "Nondestructive Testing" is based on the principle of eddy current testing, using eddy current coils to apply magnetic fields to identify seamed steel pipes by detecting eddy currents.