Common Materials of Carbon Seamless Steel Pipes

Carbon seamless steel pipes are one of the most common types, mainly composed of carbon and iron. According to the different carbon content, they can be divided into low carbon steel, medium carbon steel and high carbon steel. Mild steel pipes (such as 20# steel) have good weldability and toughness, suitable for general structural purposes; medium carbon steel pipes (such as 45# steel) have high strength and hardness, suitable for manufacturing mechanical parts; high carbon steel pipes are often used to manufacture knives and molds due to their high hardness and wear resistance.

Production process

1. Hot rolling process

The steel billet is heated to a high temperature and then rolled by a rolling mill to form a seamless steel pipe. The hot rolling process can produce steel pipes with larger diameters and thicker walls, which are suitable for some large-scale engineering and heavy machinery fields. Large-diameter casing pipes used to transport oil and gas in octg pipes are often manufactured using hot rolling processes.

2. Cold drawing process

On the basis of hot-rolled steel pipes, the diameter and wall thickness of the steel pipes are further reduced through the drawing action of the cold drawing machine, thereby improving the dimensional accuracy and surface quality of the steel pipes. The cold drawing process is suitable for some fields with high requirements for dimensional accuracy and surface quality, and is often used in precision machinery, automobile manufacturing, etc., to provide a basis for ensuring the precise matching of parts.

Common materials

Carbon seamless steel pipes have a variety of materials to meet different application scenarios and engineering needs. The following are some of the common materials:

1. Carbon steel

This is an alloy steel mainly composed of carbon and a small amount of other elements, with good mechanical properties, processing properties and welding properties. Carbon steel seamless steel pipes are suitable for the transmission of non-corrosive media and general-purpose structural engineering.

2. High carbon steel

The carbon content is high, generally above 0.5%. High carbon steel has high hardness and strength, and is suitable for occasions requiring wear resistance and high strength, such as the manufacture of components such as drill pipes in coal mines and oil mining. However, it should be noted that high carbon steel has poor corrosion resistance. If used in an environment with medium corrosion, anti-corrosion treatment is required.

3. Alloy steel

By adding some alloy elements to steel, the performance of steel is improved. It is often used in specific working environments or occasions that need to withstand specific stresses.

Common material models

Q195

It has lower strength and better plasticity and toughness, and good processing performance. It is often used to make some parts and pipes that do not require high strength, such as pipes for low-pressure fluid transportation. It is also a common material for pup joints of some simple structures.

Q215

It has slightly higher strength than Q195 and can be used to make mechanical parts and building structural parts that do not require high strength. It is more common in some ordinary steel structure projects.

Q235

It is a commonly used carbon structural steel with good comprehensive performance, moderate strength, good plasticity and toughness. It can be welded, riveted, bolted and other processing. It is widely used in building structures, machinery manufacturing, vehicle manufacturing and other fields, such as beams and columns in buildings, transmission shafts in machinery, etc.

#10

High-quality carbon structural steel has good cold processing performance and certain strength. It is often used to manufacture mechanical parts and pipes, such as bolts, nuts, tubings, etc.

#20

The strength is slightly higher than #10. It can be used to manufacture some mechanical parts that bear medium loads, such as gear shafts, etc. It is also often used to manufacture some high-pressure container pipes.

#35

It has high strength and good toughness. It can be tempered to manufacture some mechanical parts that bear large forces, such as crankshaft connecting rods, etc.

#45

It is a medium-carbon structural steel. After tempering, it has good comprehensive mechanical properties and is used to manufacture some important mechanical parts, such as machine tools, spindles, and automobile transmission shafts.

Material characteristics

1. Chemical composition

The main chemical composition of carbon seamless steel pipe is carbon (C), which usually contains a small amount of silicon (Si), manganese (Mn), sulfur (S), phosphorus (P) and other elements. The content and proportion of these elements determine the mechanical properties and processing properties of the steel pipe.

2. Mechanical properties

It has high strength and hardness and can withstand large pressure and tension. At the same time, it also has certain toughness and plasticity, and can withstand impact and deformation to a certain extent. Its tensile strength, yield strength, elongation and other mechanical properties vary according to different grades and specifications.

3. Processing performance

Good processability, can be processed into steel pipes of various shapes and sizes through hot rolling, cold rolling, cold drawing and other processes. At the same time, welding, cutting, bending and other processing operations can also be performed to meet different engineering needs.

Summary

When purchasing carbon seamless steel pipes, it is necessary to comprehensively consider and select suitable materials based on specific application scenarios, engineering requirements and budget factors. At the same time, it is also necessary to pay attention to choosing products produced by regular factories to ensure that the product quality and performance meet the requirements.

Read more: Roughness of carbon steel pipe or Thermal conductivity of carbon steel pipe