Chemical Composition of Martensitic Stainless Steel S45990 9Cr18Mo

Chemical Composition of 9Cr18Mo S45990 Martensitic Stainless Steel

9Cr18Mo stainless steel grade is a martensitic type stainless steel grade belonging to the S45990 martensitic stainless steel family, which is commonly used in the manufacture of components and parts that require high strength and corrosion resistance. The 9Cr18Mo steel grade is composed of 9% chromium and other essential elements, including 18% molybdenum, 3.2% nickel, 0.5% nitrogen, 0.5% manganese, 0.5% silicon, 0.2% phosphorus, and 0.35% sulfur. 9Cr18Mo steel is known for its combination of excellent corrosion resistance, wear resistance, and toughness.

The 9Cr18Mo steel grade is commonly used for parts and components in the structural engineering and construction industries, as well as automotive and aerospace fields. The corrosion resistance of the 9Cr18Mo stainless steel grade is due to its relatively high chromium content, while the high molybdenum content endows the steel with enhanced pitting and crevice corrosion resistance. The 9Cr18Mo stainless steel grade is also able to effectively resist stress-corrosion cracking in chloride-containing environments.

The mechanical properties of 9Cr18Mo stainless steel are good, and include a high yield strength, tensile strength, and elongation. For martensitic stainless steel grades in particular, 9Cr18Mo is noted for its very high impact toughness, owing to its high silicon and molybdenum content. At elevated temperatures, the 9Cr18Mo stainless steel grade displays excellent oxidation characteristics and can maintain a good degree of creep strength.

Finally, 9Cr18Mo stainless steel is relatively easy to join using welding or brazing processes. Notably, the presence of nickel does pose a risk of hydrogen embrittlement, and so particular care should be taken to ensure that corrosion-resistant coatings, sealants, and vacuum brazing processes are employed when welding 9Cr18Mo steel.

In conclusion, the 9Cr18Mo S45990 martensitic stainless steel grade is a corrosion and wear resistant steel grade that can be used in a variety of structural engineering, construction, automotive, and aerospace applications. The 9Cr18Mo stainless steel grade is characterised by good strength, cracking resistance and excellent impact toughness, as well as being relatively easy to weld.

Chemical Composition of the Martensitic 9Cr18Mo Stainless Steel S45990

Martensitic stainless steel 9Cr18Mo (S45990) is an alloy of chromium, nickel, and molybdenum. Its main chemical composition is as follows:

Carbon (C): 0.10-0.20%.

Manganese (Mn): 0.70-1.20%.

Phosphorus (P): 0.010-0.040%.

Sulphur (S): 0.020-0.040%.

Silicon (Si): 0.50-1.00%.

Chromium (Cr): 17.00-20.00%.

Nickel (Ni): 1.00-2.00%.

Molybdenum (Mo): 1.50-2.00%.

Martensitic stainless steel S45990 has excellent mechanical properties, corrosion resistance and toughness. It has a high strength and a delicate and good wear resistance. The steel is suitable for use in many highly corrosive environments such as chemical and petrochemical industries, power plants and offshore structures. It is also suitable for making turbine blades and has been widely used in oil and gas, nuclear and marine industries.

Due to its high content of chromium and molybdenum, martensitic stainless steel S45990 offers good formability and can be formed by cold drawing, hammering, pressing and other methods. The steel also has good magnetic properties and is non-magnetic.

With a high mechanical strength and excellent corrosion resistance, martensitic stainless steel S45990 is a highly desirable material for many applications. Its high chrome and molybdenum content provides excellent protection against heat and oxidation, making it a great choice for many industrial and commercial applications.