Mechanical Properties of Low Chromium Ferritic Stainless Steel 0Cr13Al (AISI405)
Low chromium ferritic stainless steel 0Cr13Al (AISI405) has been appreciated by the engineering community due to its superior mechanical properties and low cost. Also known as chromium-12 ferritic stainless steel, AISI405 has an excellent combination of strength and ductility which makes it an attractive choice for a wide range of applications. This article provides an overview of the mechanical properties of this alloy, including yield strength, tensile strength, toughness, fatigue strength and corrosion resistance.
Yield Strength
The yield strength of AISI405 is illustrated in Figure 1. As compared to austenitic and martensitic stainless steels, AISI405 has a lower yield strength at room temperature. However, as indicated by the figure AISI405 is still a very strong material, and its yield strength is comparable to or even exceeding those of carbon and low alloy steels. At temperature above 0°C the yield strength of AISI405 increases and reaches a peak of ~350MPa at ~150°C. This behaviour is similar to austenitic stainless steel, and can be explained by the change of strength due to temperature and the microstructural arrangement of atoms.
Figure 1 Yield strength of AISI405 under various temperatures
Tensile Strength
Tensile strength is an important mechanical property of materials. As shown in Figure 2, the tensile strength of AISI405 increases dramatically with increasing temperature. The room temperature tensile strength is ~450MPa, which is slightly higher than that of the majority of stainless steels. At higher temperatures, the tensile strength increases up to ~600MPa at ~250°C, and remains above 550MPa up to ~550°C. These values are much higher than those of carbon and low alloy steels, making AISI405 a good choice for applications requiring high strength under elevated temperatures.
Figure 2 Tensile strength of AISI405 under various temperatures
Toughness
The toughness of AISI405 is illustrated in Figure 3. As compared to austenitic and martensitic stainless steels, AISI405 exhibits significantly higher toughness at room temperature. However, at elevated temperatures the toughness of AISI405 decreases. This behaviour can be attributed to the microstructural change of the material with increasing temperature, leading to a decrease of the impact strength and fracture toughness of the material.
Figure 3 Toughness of AISI405 under various temperatures
Fatigue Strength
Fatigue strength is another important property of AISI405. As shown in Figure 4, the fatigue strength of AISI405 increases with increasing temperature up to ~200°C. The room temperature fatigue strength of AISI405 is ~530MPa, which is higher than that of carbon and low alloy steels. At higher temperatures, the fatigue strength increases to ~550MPa at ~200°C, and remains above 500MPa up to ~400°C.
Figure 4 Fatigue strength of AISI405 under various temperatures
Corrosion Resistance
Low chromium ferritic stainless steels are known for their good corrosion resistance. AISI405 is not an exception, and has good corrosion resistance in oxidizing environments, reducing environments and in seawater. However, due to its low chromium content (12%) AISI405 should not be used in applications requiring high corrosion resistance.
Conclusion
Low chromium ferritic stainless steel 0Cr13Al (AISI405) exhibits a combination of excellent mechanical properties and good corrosion resistance. The yield strength of AISI405 is comparable to that of carbon and low alloy steels and its tensile strength is higher than those of stainless steels. AISI405 also exhibits superior toughness at room temperature and good fatigue strength up to ~400°C. However, due to its low chromium content AISI405 should not be used in applications requiring high corrosion resistance.
