Expansion Coefficient Of Heat-resistant Steel
Apr 20, 2025
15.5 x 10^-6/°C (X15CrNiSi25-20) / 16.5 x 10^-6/°C (F304H) / 16-17 μm/m·K (321 stainless steel)
The following is a detailed description of the thermal expansion coefficient of several common heat-resistant steels:
X15CrNiSi25-20 (German DIN standard 1.4841)
Thermal expansion coefficient (20~200°C): 15.5 x 10^-6/°C
It is an austenitic heat-resistant steel with a high chromium and nickel content (Cr 24-26%, Ni 19-21%), suitable for high-temperature environments such as chemical reactors, nuclear reactor components, etc.
F304H (American Standard Austenitic Heat Resistant Steel)
Thermal Expansion Coefficient: 16.5 x 10^-6/°C
The chromium and nickel content is low (Cr 18%, Ni 8%), but it still has good heat resistance and is often used in petroleum and chemical equipment pipelines.
321 Stainless Steel (Austenitic Stainless Steel)
Thermal Expansion Coefficient: 16 to 17 μm/m·K (i.e. 16-17 x 10^-6/°C)
Contains titanium stabilizing elements and is suitable for high temperature corrosive environments, but the specific data source is not detailed.
Summary: The difference in expansion coefficients of different heat-resistant steels is mainly due to chemical composition (such as chromium and nickel content) and crystal structure (austenite stability). If you need accurate data, it is recommended to refer to the standard test report of the specific material.
