Common materials and steel grades for seamless steel pipes

Common materials and steel grades for seamless steel pipes

Depending on the material and purpose of seamless steel pipes, a variety of steel grades and materials are used to meet different technical requirements. The following is a classification of common seamless steel pipe materials and steel grades:

1. Carbon Steel (Carbon Steel)
Low carbon steel
Carbon content is less than 0.25%, good plasticity, suitable for cold processing:
Q195, Q215, Q235: Common pipes commonly used for conveying fluids.
20#, 10#: Commonly used for structural pipes and boiler pipes.
Medium carbon steel
Carbon content is between 0.25% and 0.6%, with high strength, but reduced plasticity and toughness:
45#, 50#: Mostly used for mechanical structures and engineering steel pipes.
High carbon steel
Carbon content is higher than 0.6%, high hardness, but poor toughness:
Commonly used for specific purposes, less used in seamless steel pipes.

2. Alloy Steel
By adding alloy elements to improve performance, it is used in special environments and high performance requirements:
Low alloy steel
16Mn, Q345B, Q355B: excellent mechanical properties, widely used in structures and fluid transportation.
High alloy steel
12Cr1MoV, 15CrMo, P22: resistant to high temperature and high pressure, commonly used in high-pressure boilers and petrochemical equipment.
Cr-Mo series steel: suitable for heat-resistant and corrosion-resistant fields.

3. Stainless Steel
Excellent corrosion resistance, commonly used in chemical, food, medical and other fields:
304, 316, 321: Austenitic stainless steel, good corrosion resistance and high temperature resistance.
410, 420: Martensitic stainless steel, high strength, but weak corrosion resistance.
2205, 2507: Duplex stainless steel, with both high strength and corrosion resistance.

4. Special steel grades
High temperature alloy steel
Used in special fields such as aviation and nuclear industry:
GH4169, GH2132: high temperature and corrosion resistance.
Corrosion-resistant alloy steel
Monel, Inconel series: used in highly corrosive environments.

5. Comparison of steel grades of commonly used foreign standards
American steel grades (ASTM/ASME)
A106 Gr.B: ordinary carbon steel pipe, commonly used for high temperature transportation.
A335 P5, P9, P11, P22: high temperature pressure-resistant alloy steel.
A312 TP304, TP316: stainless steel seamless steel pipe.
Japanese steel grades (JIS standard)
STPG370, STPG410: steel for ordinary transportation pipelines.
SUS304, SUS316: stainless steel seamless steel pipe.
European steel grades (EN/DIN standard)
E235, E355: structural steel.
1.4301 (304), 1.4404 (316L): stainless steel pipe.
Russian steel grade (GOST standard)
20, 09G2S: ordinary carbon steel.
12X1MF, 15X5M: alloy steel pipe, resistant to high temperature and high pressure.

Reference factors when selecting steel grade
Application: conveying fluids, pressure-bearing equipment, mechanical structures, etc.
Environment: whether corrosion resistance, high temperature resistance, low temperature resistance and other properties are required.
Process requirements: cold drawing, hot rolling or precision processing requirements.