High-Temperature Carbon Steel Pipe Models

High-Temperature Limits of Carbon Steel Pipe

The high-temperature limit of carbon steel pipe depends primarily on the material composition and standard specifications.

According to mainstream standards such as ASTM A106/A53 and GB/T 8163, the long-term safe operating temperature of ordinary carbon steel (such as Q235 and 20# steel) is generally 400-450°C, with short-term peak temperatures reaching 480°C (refer to ASME B31.3, Specification for Pressure Piping). Above this temperature, the material undergoes significant creep (slow plastic deformation) and oxidation, resulting in a sharp drop in strength.

Note:

1. Effect of Carbon Content

Low-carbon steel (such as 20# steel) has better temperature resistance than high-carbon steel, as high-carbon steel is more susceptible to graphitization and embrittlement at high temperatures.

2. Standard Differences

Chromium-containing alloy steels such as ASTM A335 P11 can withstand temperatures exceeding 550°C, but strictly speaking, they are no longer considered ordinary carbon steel.

Factors Affecting the High-Temperature Performance of Carbon Steel Pipe

1. Material Composition

Elements such as manganese (Mn) and silicon (Si) can enhance high-temperature strength, but excessive amounts can reduce plasticity.

Impurities such as sulfur (S) and phosphorus (P) accelerate high-temperature embrittlement.

2. Environmental Conditions

Oxidizing environments (such as flue gases containing oxygen) can accelerate surface corrosion of pipes, requiring a 20-30°C reduction in the actual temperature resistance.

Under high-pressure conditions, the upper temperature limit needs to be further reduced (refer to API 570 inspection standard).

3. Heat Treatment

Normalized pipes offer more stable high-temperature performance than hot-rolled pipes.

Comparison: Pipes Made of Other Materials

Compared to ordinary carbon steel pipes, pipes made of other materials have different high-temperature resistance characteristics.

1. Stainless Steel Pipes

Stainless steel pipes offer excellent corrosion resistance and good high-temperature resistance, with a temperature resistance of 600-900°C. They are suitable for environments requiring both corrosion resistance and heat resistance.

2. High-Temperature Alloy Pipe

Nickel-based high-temperature alloy pipes can withstand even higher temperatures, operating at temperatures exceeding 1000°C, making them an ideal choice for extremely high-temperature environments.

High-temperature-resistant Carbon Steel Pipe Models

1. 20G High-Temperature Carbon Steel Pipe

20G high-temperature carbon steel pipe is a commonly used high-temperature pipe material, offering excellent resistance to high temperatures, heat pressure, and corrosion. It is primarily used in high-temperature and high-pressure pipelines in the petroleum, chemical, power, and boiler industries.

Model: 20G

Dimensions: Outer diameter 28mm-216mm, wall thickness 3.5mm-40mm

Specifications: Tensile strength ≥410MPa, yield strength ≥245MPa, elongation ≥22%

2. 12Cr1MoVG High-Temperature Carbon Steel Pipe

12Cr1MoVG high-temperature carbon steel pipe is suitable for use in high-temperature and high-pressure environments. It is widely used due to its excellent high-temperature mechanical properties and corrosion resistance. Model: 12Cr1MoVG

Dimensions: OD 14mm-426mm, Wall Thickness 2.5mm-50mm

Specifications: Tensile Strength ≥ 490MPa, Yield Strength ≥ 245MPa, Elongation ≥ 22%

3. 15CrMoG High-Temperature Carbon Steel Pipe

15CrMoG high-temperature carbon steel pipe is suitable for high-temperature and high-pressure environments. It exhibits high oxidation and corrosion resistance, making it an indispensable material for high-temperature and high-pressure equipment in the petrochemical, power, and boiler industries. Model: 15CrMoG

Size: OD 14mm-426mm, Wall Thickness 2.5mm-50mm

Specifications: Tensile Strength ≥ 440MPa, Yield Strength ≥ 235MPa, Elongation ≥ 21%

4. ASTM A106B/C High-Temperature Carbon Steel Pipe

ASTM A106B/C high-temperature carbon steel pipe is a commonly used high-temperature pipe material, offering high-temperature, pressure-resistant, and corrosion-resistant properties. It is widely used in the petroleum, chemical, power, aviation, and aerospace industries.

Model: ASTM A106B/C

Size: OD 21.3mm-610mm, Wall Thickness 2.77mm-80mm

Specifications: Tensile Strength ≥ 415MPa, Yield Strength ≥ 240MPa, Elongation ≥ 22%

Precautions for Practical Applications

1. Temperature Monitoring

It is recommended to install thermocouples in the high-temperature section for real-time monitoring to prevent localized overheating.

2. Protective Measures

For pipes exposed to temperatures above 350°C for extended periods, heat-resistant coatings or insulation wrapping can be used.

3. Life Assessment

According to NACE SP0208, carbon steel pipes require a remaining life test after five years of continuous operation at 400°C.

Summary

The high-temperature resistance limit of carbon steel pipes is primarily between 400°C and 450°C. If higher temperatures (500°C to 600°C) are required, low-alloy heat-resistant steel pipes such as 15CrMoG and 12Cr1MoVG are recommended. For extreme environments exceeding 600°C, stainless steel or high-temperature alloy pipes should be considered.

When selecting a high-temperature carbon steel pipe, comprehensive consideration must be given to temperature, pressure, media properties, and operating cycle, and strict adherence to international standards such as ASME, API, and GB/T to ensure pipeline safety and cost-effectiveness.

Read more: What Is The Heat-resistant Temperature of Carbon Steel Pipe?