X10CrAlSi18 Introduction
X10CrAlSi18 is a chromium-aluminum stainless steel alloy that is ideal for applications requiring excellent corrosion and oxidation resistance. This alloy also features good ductility and strength up to approximately 1000°C (1831°F). Applications for X10CrAlSi18 include aircraft power turbines, industrial boilers, combustion systems, and exhaust systems.
Chemical Composition of X10CrAlSi18
The chemical composition of X10CrAlSi18 alloy is outlined in the following table.
Element Content (%)
Iron, Fe Balance
Chromium, Cr 10.0 - 11.0
Aluminum, Al 6.0 - 7.0
Silicon, Si 0.7 - 1.2
Carbon, C 0.03 - 0.08
Manganese, Mn 0.15 – 0.40
Phosphorous, P 0.035
Sulfur, S 0.030
Molybdenum, Mo 0.5 - 2.0
Nickel, Ni 0.5 - 2.0
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Mechanical Properties of X10CrAlSi18
The mechanical properties of X10CrAlSi18 can vary depending on the heat treatment and age. Typical values for tensile strength, yield strength and elongation are given in the following table, based on a hot-rolled (forgings) condition.
Tensile Strength, σts (MPa)
minimum 760
Yield Strength 0.2%, σ0.2 (MPa)
minimum 440
Elongation, ε (%)
minimum 20
Applications
The excellent oxidization and corrosion resistance of X10CrAlSi18 alloy make it a useful alloy for applications where these properties are important. Examples of applications include:
• Aircraft power turbines - X10CrAlSi18 is used as a flame-resistant material in turbines due to its high temperature strength and good thermal stability.
• Industrial boilers - X10CrAlSi18 is an ideal choice for boiler components that require corrosion and abrasion resistance. It can also be used as an insulation material.
• Combustion systems - X10CrAlSi18 resists oxidation, carburization, sulfur attack, and erosion caused by high-velocity fuel and air mixtures.
• Exhaust systems - X10CrAlSi18 has good resistance against hot gas corrosion and its high temperature strength makes it ideal for use in exhaust systems.
• Other applications - X10CrAlSi18 is often used for thermocouple sheaths and welding wire, as well as for springs and fasteners.
Heat Treatments
X10CrAlSi18 can be heat treated for improved strength and ductility. Typically, this alloy should be heated to a temperature between 975 and 1050°C (1776-1922°F) and held for a sufficient time before quenching in oil. This treatment helps to reduce the amount of retained austenite, making the material more resistant to embrittlement over time.
It is important to note that the alloy should not be overheated, as this can cause excessive grain growth and reduce the corrosion-resistance of the material. It is also important to ensure even heating of the material during the heat treatment process.
Conclusion
X10CrAlSi18 is an excellent chromium-aluminum stainless steel alloy that is ideal for applications requiring excellent oxidization and corrosion resistance. The alloy can be heat treated to improve its mechanical properties and is commonly used for applications such as aircraft power turbines, industrial boilers, combustion systems, and exhaust systems.
