Pneumatic cylinder tube (cylinder tube) is a high-precision seamless steel pipe material, and its chemical composition and manufacturing process have a decisive impact on its performance. The following is a detailed introduction:
1、 Chemical composition
The chemical composition of pneumatic cylinder tubes mainly includes elements such as carbon (C), silicon (Si), manganese (Mn), sulfur (S), phosphorus (P), chromium (Cr), etc. These elements each play an important role in steel pipes:
Carbon (C): Increases the strength and hardness of steel pipes, but excessive carbon content can reduce their plasticity and toughness.
Silicon (Si): improves the elasticity and heat resistance of steel pipes, while also aiding in deoxidation.
Manganese (Mn): enhances the strength and hardness of steel pipes, while improving their cold working performance.
Sulfur (S) and phosphorus (P): These two elements are often considered harmful in steel pipes because they reduce the plasticity and toughness of the pipes and increase brittleness. Therefore, in the manufacturing process of pneumatic cylinder tubes, it is necessary to strictly control the content of sulfur and phosphorus.
Chromium (Cr): improves the corrosion resistance and oxidation resistance of steel pipes, while also helping to form a dense oxide film to protect the surface of steel pipes.

2、 Manufacturing process
The manufacturing process of pneumatic cylinder tubes mainly includes cold drawing, hot rolling, and rolling, among which rolling processing is a key step:
Cold drawn or hot rolled:
Cold drawing: Stretching steel pipes through a drawing mold at room temperature to obtain the desired size and shape. The cold drawing process can improve the accuracy and surface quality of steel pipes, but it will increase the hardness and brittleness of steel pipes.
Hot rolling: Plastic deformation of steel pipes through rolling dies at high temperatures to obtain the desired size and shape. The hot rolling process can improve the plasticity and toughness of steel pipes, but the surface quality is relatively poor.
Rolling processing:
Principle: Rolling processing is a chip free processing method that utilizes the cold plasticity characteristics of metals at room temperature. By applying a certain pressure to the surface of the workpiece through rolling tools, the surface metal of the workpiece undergoes plastic flow and is filled into the original residual low concave valleys, thereby achieving the goal of reducing the surface roughness value of the workpiece.
Advantage:
Improving surface quality: After rolling processing, the surface roughness value of the pneumatic cylinder tube is significantly reduced, reaching Ra0.08 µ m or even lower.
Enhanced wear resistance: Rolling processing forms a cold work hardening layer on the surface of the pneumatic cylinder tube, reducing the elastic and plastic deformation of the contact surface of the grinding pair, thereby improving wear resistance.
Improving fatigue strength: After rolling processing, a residual compressive stress layer is formed on the surface of the pneumatic cylinder tube, which helps to seal small surface cracks and hinder the propagation of erosion, thereby improving fatigue strength.
Improving fit properties: After rolling processing, the reduction of surface roughness value of the pneumatic cylinder tube can improve fit properties and reduce the occurrence of leakage.