Thermal Conductivity of SUS316 Stainless Steel Pipe

Thermal Conductivity of SUS316

SUS316, also designated 316, 1.4401, or X5CrNiMo17-12-2, is an austenitic stainless steel widely used in chemical processing, food and beverage, marine, and pharmaceutical equipment. Its thermal conductivity is low compared with carbon steel, aluminum, or copper because of its austenitic crystal structure and the alloying elements chromium, nickel, and molybdenum that scatter lattice vibrations.

Typical Values

At 20 degrees C the thermal conductivity of SUS316 is about 16.2 W per meter per Kelvin, rising slowly with temperature: approximately 16.3 W per meter per Kelvin at 100 degrees C and 21.5 W per meter per Kelvin at 500 degrees C. For comparison, the conductivity of SUS304 is very similar, around 16.2 W per meter per Kelvin at 100 degrees C, while carbon steel is roughly four times higher and copper more than twenty times higher.

Does Thermal Conductivity Affect Performance

A stable and predictable thermal conductivity ensures reliable heat transfer in boilers, reactors, and heat exchangers. The value also affects the temperature distribution and thermal stress in thick-walled components, so designers use the published values at the mean metal temperature when calculating heat exchanger area and wall temperatures.

High-Temperature Limits

SUS316 maintains useful strength and corrosion resistance at high temperatures. It can be used intermittently up to about 870 degrees C and continuously up to about 925 degrees C in oxidizing atmospheres, although for long-term strength above 500 degrees C the high-carbon variant 316H is recommended. The low coefficient of thermal expansion of austenitic steel helps prevent deformation and leakage in high-temperature systems.

Applications in Heat Transfer

SUS316 tubes are used in heat exchanger tubes, boiler tubes, steam pipes, hot and cold circulation systems, and food-grade hot water systems. The smooth inner wall reduces flow resistance and improves thermal efficiency, and the molybdenum content maintains long-term stability in chlorinated, acidic, or seawater environments.

SUS316 versus SUS304 for Heat Transfer

There is no significant difference in heat transfer performance between SUS316 and SUS304. However, because SUS316 offers superior corrosion resistance, it is the better choice for high-temperature applications where corrosion is a significant factor.

Frequently Asked Questions

Q: What is the thermal conductivity of SUS316?

A: About 16.2 W per meter per Kelvin at 20 degrees C, rising to 21.5 at 500 degrees C.

Q: Why is stainless steel conductivity low?

A: The austenitic structure and alloying elements scatter heat-conducting vibrations.

Q: Is SUS316 better than 304 for heat transfer?

A: No, conductivity is similar; 316 is preferred for corrosion resistance.

Q: What is the temperature limit of SUS316?

A: Intermittent use to about 870 degrees C and continuous use to about 925 degrees C.

Q: What applications use SUS316 tubes?

A: Heat exchangers, boiler tubes, steam pipes, and hot water systems.

Q: What grade is recommended above 500 degrees C?

A: 316H for long-term high-temperature strength.

Contact us for SUS316 pipes and tubes with certified thermal and mechanical property data for your heat transfer project.