Thermal conductivity is the process by which thermal energy is transported through matter, giving the material the ability to conduct heat. Conductivity, or conduction, is normally measured in watts per kelvin per meter. A watt is a unit of power, typically defined either as volts time’s amps or as joules of energy per second. Kelvin is an absolute unit of temperature, where zero kelvins is absolute zero.
Materials with good thermal conductivity, such as certain metals, transmit large quantities of heat quickly. For instance, the copper bottom of a cooking pot heats up quickly and disperses that heat through the rest of the pot. Poor thermal conductors carry heat slowly, which can be advantageous in building materials.
Thermal Conductivity in Certain Metals
Metals contain electrons that are primarily responsible for conducting heat. The highest thermal conductivities are present in the purest of metals in their annealed state. Metals commonly encountered in low temperature work include stainless steel, carbon steel, and aluminum.
In some metals, the thermal conductivity is a strong function of the purity and the condition of the metal. For cryogenic (cold producing) applications, copper and aluminum are used where good thermal conductivity is required. Stainless steel is used in applications where a relatively poor thermal conductivity is suitable. This would be applicable to infrastructure for things like structural framing members.
Conductivity in Aluminum
Pure aluminum has a thermal conductivity of about 235 watts per kelvin per meter. Aluminum alloys tend to have much lower conductivity. However, this is rarely as low as iron and steel. Aluminum is often used in electronic heat sinks due to the metal’s good thermal conductivity.
Conductivity in Carbon Steel
The thermal conductivity of carbon steel is much lower than that of aluminum. Its thermal conductivity is around 45 watts per kelvin per meter. This material is a good and economical choice for building structural components.
Conductivity in Stainless Steel
Stainless steel has an even lower conductivity than carbon steel at about 15 watts per kelvin per meter. Stainless steel is an ideal material for structures in corrosive environments or for Architecturally Exposed Structural Steel (AESS) applications.
Benefits of Stainless Steel
Materials with low thermal conductivity prevent heat transmission. This can result in better energy efficiency and stability of the material. Stainless steel’s lower thermal conductivity makes it a good material for building facades, glass applications and curtain wall systems. Stainless steel also remains stable when in contact with heat, such as during a manufacturing process or in food processing equipment such as ovens and conveyors.
Producing Profiles for Your Needs
Stainless Structurals is a worldwide leader in the production of stainless steel structural shapes and custom profiles, including sharp cornered profiles. We use a variety of manufacturing technologies to provide our customers with the highest quality components for many different applications. Our Laser Fusion technology is especially impressive. Please contact us for more in depth information about our products and innovative manufacturing processes.