Choosing the right material grade can ensure the stability and safety of the pipe in different environments and applications. For example, Q345B is often used in structures such as bridges and ships that need to bear large loads due to its high strength and good mechanical properties at low temperatures.

Carbon content
The carbon content is one of the main parameters that determine the material grade of carbon steel pipe. Generally speaking, pipes with high carbon content also have high strength and poor toughness, while pipes with low carbon content have high toughness and poor strength. Internationally, steel pipes with a carbon content of less than 0.30% are generally called mild steel tube, steel pipes with a carbon content between 0.30%-0.60% are called medium-carbon steel pipes, and steel pipes with a carbon content between 0.60%-1.00% are called high-carbon steel pipes.

Mechanical performance parameters
The mechanical performance parameters such as strength and toughness of carbon steel pipes are also one of the important parameters of material grade. Commonly used mechanical performance parameters include tensile strength, yield strength, elastic modulus, etc. Mild steel pipes have lower mechanical properties, poor strength and toughness, while high carbon steel pipes have better mechanical properties, high strength and toughness.

Common standards
There are many international standards for the grade and performance requirements of carbon steel pipes. Among them, European standard EN, American standard ASTM, German standard DIN and Japanese standard JIS are more commonly used standards. Different standards have different regulations for the grade classification, mechanical performance parameters, chemical composition and other aspects of pipes.
‌China's carbon steel pipe material grade standards ‌ usually include the following:
‌GB/T8162‌: Seamless steel pipe for structure
‌GB/T8163‌: Seamless steel pipe for conveying fluids
‌GB3087‌: Seamless steel pipe for low and medium pressure boilers
‌GB5310‌: Seamless steel pipe for high pressure boilers
‌GB9948‌: Seamless steel pipe for petroleum cracking ‌.
These standards specify the requirements for the chemical composition, mechanical properties and manufacturing process of carbon steel pipes, ensuring the quality and reliability of the products.

Common material grades
The following are some common carbon steel pipe material grades and their uses:
1. Mild steel pipe: Q195, Q215, Q235, etc., usually used in construction, bridges and other fields.
2. Medium carbon steel pipe: 20#, 45#, 40Cr, etc., usually used in mechanical processing.
3. High carbon steel pipe: 55#, 60#, 65#, etc., usually used in spring manufacturing and other occasions.

Summary
In general, factors such as the material grade and mechanical performance parameters of carbon steel pipes will directly affect their use effect. Therefore, when purchasing and using carbon steel pipes, it is necessary to select the appropriate material grade and specification model according to actual needs.