Metallographic diagram of 18Cr2Ni4WA (quenching and tempering after carburizing at 880°C)

Microstructure of 18Cr2Ni4WA (after Quenching and Tempering at 880℃)

18Cr2Ni4WA (18Cr2Ni4WA) is an austenitic stainless steel alloy. It is a type of stainless steel alloy which has the high strength, excellent corrosive resistance and formability. It is used in oil and gas piping systems, chemical plants, and food processing industries. The microstructure of this steel is studied after quenching and tempering at 880°C.

The microstructure of 18Cr2Ni4WA after quenching and tempering at 880°C is made up of retained austenite and ferrite grains. The grains formed by tempering show a distinctive feature of 18Cr2Ni4WA. At the quenching temperature, retained austenite is the primary form of the tempered steel, but the ferrite grains become more evident after tempering. The average ferrite grain size is approximately 11.2 microns.

The retained austenite grains are Cr-rich, having higher chromium content than the ferrite grains. The retained austenite grains have much higher hardness than the ferrite grains, as the amount of chromium present in the alloy is responsible for the high strength of the steel. Moreover, the residual stress to martensite transformation is low, making the alloy resistant to distortion after quenching. The average retained austenite grain size is approximately 8.8 microns.

The microstructure of 18Cr2Ni4WA exhibits a dynamically formed microstructure that reveals a unique character of the alloy. Due to the high austenite content, the alloy exhibits excellent strength and toughness. The chromium provides an excellent corrosion resistance and the alloy is formable even after quenching and tempering. Moreover, the chromium also gives the alloy an excellent wear resistance, making it suitable to use in applications that require wear-resistant and hard steel alloys.

The microstructure of 18Cr2Ni4WA after quenching and tempering at 880℃ is an interesting character of the alloy. With its ability to retain higher chromium content, it is highly wear-resistant, strong, and formable. This alloy is widely used in many applications, especially those which require strength and corrosion resistance. The microstructure of 18Cr2Ni4WA reveals a unique character of this alloy, and its dynamic character explains the dramatic difference between the strength, corrosion resistance and formability of this alloy and other stainless steel alloys.

The 20Cr2Ni4WA steel is a low-alloy steel with carbon content of 0.18 % and is used for manufacturing powertrain, transmission, and drive components. It is precipitation hardened and used for high-temperature applications.

The microstructure of the 20Cr2Ni4WA steel after carburizing and heat treatment (quenching and tempering) consists of a ferrite matrix with a small amount of pearlite, and a minute amount of hard martensite and retained austenite.

The typical microstructure of the 20Cr2Ni4WA steel after carburizing at 880°C and heat treatment consists of a ferrite matrix with a small amount of pearlite, and a discrete network of martensite laths embedded within a martensite matrix. This martensite matrix contains a very small amount of retained austenite, which results in an increase in the hardness of the steel.

The 20Cr2Ni4WA steel has good low-temperature impact toughness, due to its high residual austenite content. The tempering temperature has great influence on the impact toughness. It increases with increasing tempering temperature and reaches a maximum at around 680°C, after which it gradually decreases.

The 20Cr2Ni4WA steel also has good wear resistance. The wear resistance increases at elevated temperatures. The maximum wear resistance is achieved with a hardness of 37 HRC, or upon tempering at 730°C.

The 20Cr2Ni4WA steel has a good combination of strength, toughness and wear resistance. It is ideal for use in the manufacture of automotive components, such as transmission, powertrain, and drive components. The 20Cr2Ni4WA steel can also be used in applications requiring high wear resistance.