Chemical Composition and Microstructure of 00Cr22Ni5Mo3N Steel

Invar 36 Steel（FeNi36）

Invar 36 steel, also known as FE Ni 36, is a nickel-iron alloy known for its unique characteristics that make it ideal for many applications. It offers superior temperature stability, superior thermal conductivity, excellent electrical conductivity and a low coefficient of thermal expansion, making it an excellent choice for a variety of industrial, medical and specialized applications. Invar 36 is also known as NILO 36, Pyromet 36 and UNS K93600.

Chemical Composition

Invar 36 steel is composed of iron (Fe), nickel (Ni), and a small amount of carbon (C). The chemical composition of Invar 36 is as follows:

• Nickel: 36%

• Iron: 64%

• Carbon: 0.02%-0.15%

• Manganese: 0.50%-1.00%

• Silicon: 0.20%-0.50%

• Chromium: 0.30%-0.75%

• Molybdenum: 0.25%-1.00%

• Copper: 0.20%-0.50%

• Phosphorus: 0.04%-0.35%

• Sulphur: 0.02%-0.20%

• Nitrogen: Less than 0.10%

• Aluminium: 0.15%-0.50%

• Titanium: Less than 0.15%

• Cobalt: 0.15%-0.50%

Microstructure

Invar 36 steel is an austenitic type of stainless steel and has an FCC Crystal structure. Its microstructure is composed of c-ferrite and austinite. The austinite phase makes up 70%-90% of the microstructure, while the c-ferrite phase makes up 10%-30%.

The austinite phase contributes to the stability of Invar 36 steel and also to its corrosion resistance. This is because austinite grains exhibit a high degree of stability and have fewer impurities than c-ferrite grains. The c-ferrite phase, on the other hand, contributes to the strength of the steel and makes it more resilient to mechanical shock.

The microstructure of Invar 36 steel is also characterized by a very small grain size and is quite homogenous. This ensures that the steel has an even and consistent grain structure, which in turn helps to improve the properties of the steel.

Conclusion

In conclusion, Invar 36 is an ideal steel for many applications because of its unique properties. It has a low coefficient of thermal expansion, excellent electrical and thermal conductivity, and excellent temperature stability. Invar 36 steel is also characterized by a homogenous grain structure and a small grain size, which helps to improve its properties and performance.

(0Cr22Ni5Mo3N) Steel

(0Cr22Ni5Mo3N) steel is a special stainless austenitic steel, which has high resistance to intergranular corrosion and pitting corrosion.

Chemical Composition

The chemical composition of (0Cr22Ni5Mo3N) steel consists of the following elements, in weight percentage:

Carbon (C) : ≤0.08;

Chromium (Cr) : 22%;

Nickel (Ni) : 5%;

Molybdenum (Mo) : 3%;

Nitrogen (N) : 0.20-0.40%.

Microstructure

The microstructure of (0Cr22Ni5Mo3N) steel consists of austenite or austenite-ferrite structure, which can be divided into polygonal ferrite, perpendicular ferrite, acicular ferrite, transgranular and intergranular ferrite. The austenite grain size can reach ASTM 4 or 5. The carbide particles formed in steel are mostly distributed along the junction of the grain boundary, and the shape of the carbide particles is mainly flake shape. In the welding zone, a large number of remnants of grains are present, and there are many ferrite inclusion particles and coarse carbide particles.

Conclusion

In summary, (0Cr22Ni5Mo3N) steel is a special stainless austenitic steel that has excellent resistance to intergranular corrosion and pitting corrosion. It has a chemical composition that contains 0.08% of carbon, 22% of chromium, 5% of nickel, 3% of molybdenum,and 0.20-0.40% of nitrogen. Its microstructure consists of austenite or austenite-ferrite structure with polygonal ferrite, perpendicular ferrite, acicular ferrite, transgranular and intergranular ferrite. Its austenite grain size can reach ASTM 4 or 5, and there are plenty of carbide particles distributed along the junction of the grain boundary.