Oxidation Resistance of Low Chromium Ferritic Stainless Steel 0Cr11Ti(AISI409), 00Cr11Ti(AISI409L)

Low-chromium ferritic stainless steel 0Cr11Ti (AISI 409) and 00Cr11Ti (AISI 409L) are two commonly used stainless steel grades with low carbon content (0.08-0.13 wt%). Due to the low chromium content, these steels are prone to localized corrosion and oxidation, so it is important to know the oxidation resistance of these materials for their potential applications. It is known that low-chromium ferritic stainless steels are susceptible to chloride stress corrosion cracking and hydrogen embrittlement, and for this reason, their oxidation resistance is often considered as an important factor.

The oxidation resistance of 0Cr11Ti and 00Cr11Ti materials is usually studied through tests such as the cyclic oxidation test, the isothermal oxidation test, or the accelerated oxidation test, which involve the exposure of the material to an oxidizing environment at elevated temperatures. The oxidation rate is then evaluated by measuring the mass gain of the oxidation products by gravimetric analysis and/or calculating the thickness of the oxide layer. Results from these studies have shown that 0Cr11Ti and 00Cr11Ti stainless steels exhibit moderate oxidation resistance, with an oxidation rate of approximately 0.2 to 1.5 micron/year. These results are comparable with those of higher chromium ferritic grades such as AISI 441, which exhibits an oxidation rate of up to 4.0 micron/year.

The oxidation resistance of the 0Cr11Ti and 00Cr11Ti stainless steel can be further improved by forming oxide-rich layers on the surface of the material to provide a protective layer. In this process, a coat of compositions such as silica, alumina, tungsten, chromium and titanium are deposited on the surface. These layers provide an effective barrier against attack by oxygen, and can also act as a diffusion barrier to slow down the oxidation process.

In conclusion, the oxidation resistance of 0Cr11Ti and 00Cr11Ti stainless steel is moderate and can be improved by forming an oxidant resistant coating. Despite the low chromium content, these steels are suitable for certain applications where oxidation resistance is not a primary concern. Thermal cycling and thermal shock tests have demonstrated their mechanical and corrosion resistance, making them an attractive material for use in certain applications.

Low Chromium Ferritic Stainless Steel 0Cr11Ti(AISI409) and 00Cr11Ti(AISI409L) possess good anti-corrosion properties, excellent formability and weldability. This is due to the presence of their low-chromium ferritic composition which provide an increased durability and resistance to oxidation. The corrosion resistance of 0Cr11Ti(AISI409) and 00Cr11Ti(AISI409L) is due to their low-chromium and ferritic compositions, which creates a layer of active oxide film on the surface of the steel. This oxide film offers protection form corrosion and can also be used as a sacrificial layer.

Due to its electrical resistivity, 0Cr11Ti(AISI409) and 00Cr11Ti(AISI409L) are commonly used in environments where corrosion resistance, heat resistance and formability are necessary. Owing to their lower chromium content, the ferritic stainless steels are significantly more economical than their more popular Chormium-Nickel-Molybdenum stainless steel counterparts. They also provide superior formability and weldability.

The anti-oxidation properties of 0Cr11Ti(AISI409) and 00Cr11Ti(AISI409L) are also very good, as they contain some chromium which helps protect the steel from oxidation when exposed to high temperatures or harsh environments. This makes these low-chromium ferritic stainless steels an ideal choice for applications where oxidation resistance and durability are critical factors.

To further improve the properties of 0Cr11Ti(AISI409) and 00Cr11Ti(AISI409L), the addition of small quantities of molybdenum and nitrogen can be advantageous. The addition of molybdenum increases the corrosion resistance, while the addition of nitrogen can further improve the anti-oxidation characteristics of the steel.

In conclusion, 0Cr11Ti(AISI409) and 00Cr11Ti(AISI409L) possess excellent anti-corrosion properties as well as good formability and weldability. The presence of the low-chromium and ferritic composition make this stainless steel more economical and less prone to oxidation when exposed to harsh environments. Small additions of molybdenum & nitrogen can further enhance these anti-corrosion properties and make them more oxidation-resistant.