Corrosion Resistance of Chromium-Nickel Austenitic Stainless Steel 00Cr18Ni18Mo5

Corrosion Resistance of 00Cr18Ni18Mo5 Austenitic Stainless Steel

Introduction

00Cr18Ni18Mo5 is an austenitic stainless steel which has a high resistance to both general and localized corrosion including stress corrosion cracking. The alloy is designated as 00Cr18Ni18Mo5 according to the International Standardization Organization (ISO) system and is produced in the form of plates, bars and pipes. 00Cr18Ni18Mo5 is often used for making large and complex parts due to its high content of alloying elements and its capability to undergo deformation without cracking.

Composition

00Cr18Ni18Mo5 is composed of 18 – 19% chromium, 17 – 18% nickel and 5 – 6 % molybdenum. Additional elements in the alloy are manganese, silicon and nitrogen. The addition of molybdenum helps to enhance the corrosion resistance of the alloy and this element is mostly present in the form of carbides in the solution annealed condition.

Forms of Corrosion

00Cr18Ni18Mo5 has a very good resistance to a wide range of corrosive media due to its high chromium and nickel content and the presence of molybdenum. The alloy has a good resistance to general corrosion and is also resistant to pitting and crevice corrosion in a wide range of corrosive media. It is also resistant to both intergranular and stress corrosion cracking. However, the alloy is susceptible to chloride stress corrosion cracking and it is important to select suitable material when this kind of environment is present.

Structure

The structure of 00Cr18Ni18Mo5 is ferrite and austenite which is stabilized by the addition of nitrogen and/or by means of low nitrogen alloys which contain titanium and/or niobium. This structure has a significant influence on the corrosion resistance of the alloy. A higher nitrogen content in the alloy allows for a higher corrosion resistance as the chromium and nickel which are present in the alloy will have increased solubility in the matrix.

Testing

The corrosion resistance of 00Cr18Ni18Mo5 can be tested in variety of ways, including the use of corrosion coupons, exposure test panels and exposure testing. Corrosion coupons can be exposed to corrosive environments and the degree of corrosion can then be assessed by measuring the weight loss or the amount of corrosion products on the coupon. Exposure test panels can be used to assess the corrosion resistance of the alloy and how it performs in different environments and exposure tests can be used to determine service conditions.

Conclusion

00Cr18Ni18Mo5 is an austenitic stainless steel which has a high resistance to both general and localized corrosion including stress corrosion cracking and pitting corrosion. The alloy contains 18-19% chromium, 17-18% nickel and 5-6% molybdenum, which are the main elements that contribute to its high corrosion resistance. The alloy has a ferrite and austenite structure which is stabilized by the addition of nitrogen, titanium and niobium. The corrosion resistance of 00Cr18Ni18Mo5 can be tested using corrosion coupons, exposure test panels and exposure testing in order to determine service conditions.

00Cr18Ni18Mo5 austenitic stainless steel is a stainless steel alloy commonly used in many industrial settings. Its composition is comprised of approximately 18% chromium (Cr), 18% nickel (Ni) and 5% molybdenum (Mo). This chromium-nickel-molybdenum combination provides this alloy with good ductility, formability, weldability and corrosion resistance.

00Cr18Ni18Mo5 is a ferritic stainless steel alloy and has a microstructure made up predominantly of low-carbon martensite. This alloy can be hardened through cold working due to its martensitic structure.

00Cr18Ni18Mo5 is a very corrosion-resistant stainless steel alloy and can be used in a wide variety of environments. It exhibits outstanding resistance to general corrosion and pitting in mild to moderately aggressive chemical environments, reducing acids and neutral chloride-containing environments. This alloy also shows good oxidation and crevice corrosion resistance and is suitable for applications exposed to high temperatures.

00Cr18Ni18Mo5 has a number of uses including the chemical industry, oil refineries, and food processing equipment. It can also be used to make chemical and petrochemical storage tanks and piping systems and ships, as it has excellent resistance to chloride ion stress corrosion cracking.

Overall, 00Cr18Ni18Mo5 austenitic stainless steel is an excellent stainless steel alloy due to its wide range of excellent properties. These include good formability, welding, ductility, hardenability and corrosion resistance, making it suitable for a wide range of industrial applications.