Carbon Steel Pipe Temperature Range

Carbon steel pipes (CS pipe full form)  are metal pipes primarily composed of iron and carbon. Their applicable temperature range is influenced by a combination of material composition, manufacturing process, and operating environment. According to international standards such as ASTM A106/ASTM A53, the typical safe operating temperature range for carbon steel pipes is -29℃ to 425℃.

Temperature Range of Carbon Steel Pipes

1. Low Temperature Limit (-29℃)

When the temperature is below -29℃, the toughness of carbon steel decreases significantly, making it prone to brittle fracture.

Steel pipes that have passed low-temperature impact tests (such as ASTM A333 Grade 6) must be used.

2. High Temperature Limit (425℃)

Above 425℃, the oxidation resistance and strength of carbon steel decrease sharply, and prolonged high temperatures may lead to creep deformation.

Chromium-molybdenum alloy steel (such as ASTM A335 P11) must be selected for high-temperature environments.

Influence of Temperature on the Performance of Carbon Steel Pipes

1. Changes in Mechanical Properties

High Temperature Environment: Increased temperature reduces yield strength and tensile strength. For example, the tensile strength of 20# carbon steel decreases by approximately 15% at 300℃.

Low-temperature environments: Low temperatures may cause material embrittlement, requiring verification through Charpy V-notch impact testing (e.g., ≥27J at -46℃).

2. Differences in Corrosion Resistance

High temperatures accelerate oxidation reactions; above 425℃, surface aluminizing or galvanizing treatment should be considered.

In low-temperature environments, condensate may cause electrochemical corrosion, requiring enhanced insulation or coating protection.

Temperature Requirements for Different Application

1. Boilers and High-Pressure Steam Systems

According to ASME standards, carbon steel pipes are allowed to briefly exceed 450℃ in high-pressure steam systems, but the wall thickness reduction rate must be checked periodically.

2. Cryogenic Storage and Transportation Equipment

LNG pipelines and other cryogenic scenarios (-162°C) require austenitic stainless steel or nickel-based alloys. Carbon steel pipes are only suitable for secondary insulation layer support structures.

Temperature Requirements for Different Standard Carbon Steel Pipes

Use of Carbon Steel Pipes in Extreme Temperatures

1. Temperature ≥ 400℃

P11 or P22 alloy steel is strongly recommended. Wall thickness needs to be increased or stress value reduced.

2. Temperature ≤ -29℃

Ordinary carbon steel is prohibited. Replace with low-temperature grade carbon steel A333.

3. Frequent Temperature Fluctuations

Prone to thermal fatigue cracks; higher toughness materials should be selected. Corrosion + high temperature coexistence: A coating + alloy steel combination design can be used.

FAQ

1. What is the Maximum Temperature That Carbon Steel Pipes Can Withstand?

Maximum long-term operating temperature of ordinary carbon steel: 425℃. Short-term not exceeding: 450℃ (meets ASME requirements).

2. Can Carbon Steel Pipes Be Used for LNG (-162℃)?

No.

Austenitic stainless steel must be used for LNG main lines; carbon steel can only be used in auxiliary structures.

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