Alloy steel pipe introduction

The materials of alloy tubes are roughly: 16-50Mn, 27SiMn, 40Cr, 12-42CrMo 16Mn 12Cr1MoV T91 27SiMn 30CrMo 15CrMo 20G Cr9Mo 10CrMo910 15Mo3 15CrMoV 35CrMoV 45CrMo, 15CrMoG, 12CrMoV, 45Cr, 50Cr, 45CrNiMo, etc.

Alloy pipe standard

Alloy pipe has a hollow section and is widely used as a pipeline for transporting fluids, such as pipelines for transporting oil, natural gas, gas, water and certain solid materials. Compared with solid steel such as round steel, alloy steel pipe is lighter in weight when the bending and torsional strength is the same. Alloy steel pipe is a kind of economical section steel, which is widely used in the manufacture of structural parts and mechanical parts, such as oil drill pipes, automobile transmission Axles, bicycle racks, and steel scaffolding used in building construction, etc. The use of alloy steel pipes to manufacture ring parts can improve the utilization rate of materials, simplify the manufacturing process, save materials and processing man-hours, such as rolling bearing rings, jack sets, etc., which have been widely used in steel pipes. Alloy steel pipe is also an indispensable material for various conventional weapons. Gun barrels, barrels, etc. must be made of steel pipes. Alloy steel pipes can be divided into round pipes and special-shaped pipes according to the shape of the cross-sectional area. Due to the condition that the circumference is equal, the area of the circle is the largest, and more fluid can be transported with a circular tube. In addition, when the ring section is subjected to internal or external radial pressure, the force is relatively uniform, so most steel pipes are round pipes.

Steel pipe weight calculation formula: [(outer diameter - wall thickness)* wall thickness]*0.02466=kg/m (weight per meter)

Dimensional tolerance of alloy steel pipe:

1. Classification of aluminum alloy tubes 2.1Alloy series based on pure aluminum. 3. Aluminum alloy with copper as the main alloying element 4. Aluminum alloy with manganese as the main alloying element 5. Titanium alloy tube Use: Titanium alloy tube Mainly used in aviation. It is a special alloy tube for aviation with high hardness and high temperature resistance. 6. aluminum alloys with silicon as the main alloying element 7. aluminum alloys with magnesium as the main alloying element 8. aluminum alloys with magnesium and silicon as the main alloying elements 9.  aluminum alloys with zinc as the main alloying element 10. Alloy tubes There are both relationships and differences with seamless pipes, and they cannot be confused. 11. Alloy pipes are steel pipes defined according to production materials (that is, materials), as the name implies, they are pipes made of alloys; while seamless pipes are steel pipes defined according to the production process (seamless), which is different from seamless pipes The most common is seamed pipes, including straight seam welded pipes and spiral pipes.

The meanings of elements and symbols in alloy steel materials
Steel grades, referred to as steel grades, are names for each specific steel product and a common language for people to understand steel. The expression method of Ganghao in my country is generally represented by a combination of Chinese pinyin letters, chemical symbols and Arabic numerals.

Next, let's introduce the meanings of the elements and symbols in the alloy steel material in detail.
●1. The two digits at the beginning of the steel number indicate the carbon content of the steel, expressed in ten-thousandths of the average carbon content, such as 40Cr.
●2. The main alloying elements in steel, except a few microalloying elements, are generally expressed in a few percent. When the average alloy content is less than 1.5%, the steel grade
Generally, only the element symbol is marked, but not the content. However, in special cases, if it is easy to cause confusion, the number "1" can also be marked after the element symbol.
For example, steel grades "12CrMoV" and "12Cr1MoV", the chromium content of the former is 0.4-0.6%, the latter is 0.9-1.2%, and the rest of the ingredients are all the same
When the average content of alloying elements is ≥ 1.5%, ≥ 2.5%, ≥ 3.5% ..., the content should be marked after the element symbol, which can be expressed as 2, 3, 4 ...etc. For example 18Cr2Ni4WA.
●3. Alloying elements such as vanadium V, titanium Ti, aluminum AL, boron B, and rare earth RE in steel are all microalloying elements. Although the content is very low, they should still be included in the steel grade
marked out. For example, vanadium in 20MnVB steel is 0.07-0.12%, and boron is 0.001-0.005%.
●4. For high-grade high-quality steel, "A" should be added at the end of the steel number to distinguish it from general high-quality steel.
●5. For special-purpose alloy structural steel, the steel number is prefixed (or suffixed) with a symbol representing the purpose of the steel. For example, 30CrMnSi steel for rivet screws,
The steel grade is expressed as ML30CrMnSi.
●6. For professional low-alloy high-strength steel, it should be marked at the end of the steel number. For example, 16Mn steel, the special steel grade used for bridges is "16Mnq", steam
The special steel grade for the vehicle frame is "16MnL", and the special steel grade for the pressure vessel is "16MnR".
Alloy steel pipe Mechanical properties

Dimensions and tolerances of seamless steel pipes