Commonly used stainless steel seamless pipes in industrial projects

First, the concept of stainless steel seamless pipes

Stainless steel seamless pipes are a kind of hollow long steel strips, which are widely used as pipelines for conveying fluids, such as oil, natural gas, water, coal gas, steam, etc. In addition, when bending and torsional strength are the same, the weight is light, so it is also widely used in the manufacture of mechanical parts and engineering structures. It is also commonly used to produce various conventional weapons, gun barrels, shells, etc.

Second, the application of stainless steel seamless pipes

Stainless steel pipes are safe, reliable, hygienic, environmentally friendly, economical, and applicable. The thin-walled pipes and the successful development of new reliable, simple, and convenient connection methods have given them more advantages that other pipes cannot replace. There will be more and more applications in engineering, and the use will become more and more popular, and the prospects are promising. With the implementation of my country's reform and opening-up policy, the national economy has achieved rapid growth, and a large number of urban residential buildings, public buildings, and tourist facilities have been built, which has put forward new requirements for hot water supply and domestic water supply. In particular, people pay more and more attention to water quality issues, and the requirements are constantly improving. Galvanized steel pipes, a commonly used pipe material, will gradually withdraw from the stage of history under the influence of relevant national policies due to their easy corrosion. Plastic pipes, composite pipes, and copper pipes have become common pipes for pipeline systems. However, in many cases, stainless steel pipes are more advantageous, especially thin-walled stainless steel pipes with a wall thickness of only 0.6 to 1.2 mm, which are safe, reliable, sanitary, environmentally friendly, and economical in high-quality drinking water systems, hot water systems, and water supply systems that put safety and hygiene first. It has been proven by domestic and foreign engineering practices to be one of the new, energy-saving, and environmentally friendly pipes with comprehensive performance in water supply systems. It is also a very competitive water supply pipe material, which will surely play an incomparable role in improving water quality and improving people's living standards. In the building water supply system, since the galvanized steel pipe has ended its glorious history of a hundred years, various new plastic pipes and composite pipes have developed rapidly, but various pipes still have some shortcomings to varying degrees and are far from fully meeting the needs of the water supply system and the country's requirements for drinking water and related water quality. Therefore, relevant experts predict that building water supply pipes will eventually return to the era of metal pipes. According to foreign application experience, thin-walled stainless steel pipes are recognized as one of the pipes with comprehensive performance among metal pipes.

Third, the material and standard of stainless steel seamless pipes

Material: 201 (1Cr17Mn6Ni5N), 202 (1Cr18Mn8Ni5N), 301 (1Cr17Ni7) 302 (1Cr18Ni), 304 (0Cr18Ni9), SS304, TP304 304L (00Cr19Ni10), SS304L, TP304L 321 (1Cr18Ni9Ti), SS321, TP321 316 (0Cr17Ni12Mo2), SS316, TP316 316L (0Cr17Ni14Mo2), SS316L, TP316L 310S (0Cr25N20), SS310S, TP310S Stainless steel pipes implement the standard GB2270-80 Stainless steel seamless pipes, GB/T14976-94 Stainless steel seamless pipe for fluid transportation GB/T14975-94 Stainless steel seamless pipe for structure, GB13296-91 Stainless steel seamless pipe for boiler and heat exchanger (GJB2608-96) (YB676-73) Structural steel thick wall seamless pipe for aviation (GJB2296-95) (YB678-71) Stainless steel seamless pipe for aviation, (YB/T679-97) (YB679-71) 18A hollow rivet thin wall seamless pipe for aviation (GJB2609-96) (YB680-71) Structural thin wall seamless pipe for aviation (YB/T681-97) (YB681-71) 20A thin wall seamless pipe for aviation GB3090-82 Stainless steel small diameter pipe GB5310-95 Seamless pipe for high pressure boiler GB3087-82 Low and medium pressure seamless pipe GB3089-92 Stainless acid-resistant ultra-thin wall seamless steel pipe GB9948-88 Petroleum cracking seamless steel pipe, ASTM A213 Ferrite and austenite alloy steel seamless steel pipe for boilers and heat exchangers ASTM A269 General purpose austenitic stainless steel seamless steel pipe and welded steel pipe ASTM A312 Austenitic stainless steel seamless steel pipe welded steel pipe welded steel pipe ASTM A450 General requirements for carbon steel, ferrite and austenite alloy steel pipes ASTM A530 General requirements for ferrite and alloy steel for special purposes, ASTM A789 General requirements for carbonite austenite stainless steel seamless steel pipe and welded steel pipe JIS G3456-88 Stainless steel pipe for mechanical structure JIS G3448-88 Stainless steel pipe for ordinary pipelines, JIS G3459-88 Stainless steel pipe for pipelines, JIS G3463-88 Stainless steel pipe for boilers and heat exchangers Q/HYAD 101-91 Seamless long steel pipe for chemical industry, (0Cr18NI11T) Q/HYAD 103-91 00Cr18Ni5MO3Si2 duplex stainless steel seamless steel pipe

Fourth, the classification of stainless steel seamless steel pipes

1. Classification by production method:

(1) Seamless steel pipe - cold drawn steel pipe, extruded steel pipe, cold rolled pipe Stainless steel seamless steel pipe is a long steel strip with a hollow cross-section and no seams around it.

Manufacturing process and flow of seamless steel pipe: smelting> ingot> rolling> sawing> peeling> perforation> annealing> pickling> lime coating> cold drawing> cutting> pickling> storage

Features of seamless steel pipe

From the above process flow, we can easily see that: first, the thicker the wall thickness of the product, the more economical and practical it is, and the thinner the wall thickness, the higher the processing cost; second, the process of the product determines its limitations. Generally, seamless steel pipes have low precision: uneven wall thickness, low brightness of the inner and outer surfaces of the pipe, high cost of fixed length, and pitting and black spots on the inner and outer surfaces are not easy to remove; third, its detection and shaping must be processed offline. Therefore, it has demonstrated its superiority in high pressure, high strength, and mechanical structure materials.

(2) Welded steel pipe

(a) Classification by process - gas-shielded welded steel pipe, arc welded steel pipe, resistance welded steel pipe (high frequency, low frequency)

(b) Classification by weld seam - straight seam welded pipe, spiral welded pipe

Stainless steel welded steel pipe: Welded steel pipe is referred to as welded pipe, which is a steel pipe made by welding a steel plate or steel strip after curling and forming by a unit and a mold.

The manufacturing process and flow of welded steel pipe: steel plate> striping> forming> welding> induction bright heat treatment> internal and external weld treatment> shaping> sizing> eddy current detection> laser diameter measurement> pickling> storage

Characteristics of welded steel pipe: From the above process flow, it is not difficult to see that: First, the product is continuously produced online. The thicker the wall thickness, the greater the investment in the unit and welding equipment, and the less economical and practical it is. The thinner the wall thickness, the lower its input-output ratio will be; secondly, the process of the product determines its advantages and disadvantages. Generally, welded steel pipes have high precision, uniform wall thickness, and high brightness of the inner and outer surfaces of the steel pipe (the surface brightness of the steel pipe is determined by the surface grade of the steel plate), and can be arbitrarily sized. Therefore, it embodies its economy and aesthetics in high-precision, medium, and low-pressure fluid applications.

2. Classification by cross-sectional shape (1) Circular steel pipe (2) Rectangular steel pipe

3. Classification by wall thickness (1) Thin-walled steel pipe (2) Thick-walled steel pipe