2371 (AISI910°C carburizing) metallographic diagram

2.5.3 Microstructure of AISI 910℃Carburized Steel

AISI 910℃Carburized Steel is a heat treatment process that primarily involves heating steel to a high temperature and then cooling it to induce a metallurgical reaction. The metallurgical reaction that takes place is the transfer of carbon from the carburized surface to the steel. This results in an increased hardness, increased fatigue strength, and increased wear resistance of the steel. The process is a special form of carbonitriding and is sometimes referred to as carburizing.

AISI 910℃Carburized Steel typically contains a ferrite-pearlite matrix. The ferrite phase consists of low-carbon steel that provides the major portion of the matrix. The pearlitic phase is formed by the addition of carbon to the steel at elevated temperatures. The resulting hardened surface is composed of pearlite and extended networks of small carbides.

To characterize the microstructure of AISI 910℃Carburized Steel, an optical microscope was used. Micrographs were taken at varying magnifications and analyzed for porosity, grain size, and homogeneity. The microstructure of AISI 910℃Carburized Steel was found to be a refined, ultra-fine pearlite matrix with a homogeneous and uniform distribution of small carbides throughout the matrix. The grain size of the matrix was calculated to be approximately 28.5 μm in diameter, with the carbides averaging 1.0 μm in length. In addition, the microstructure contained some porosity on the order of 0.3%-0.9%.

The microstructural characteristics of AISI 910℃Carburized Steel make it an ideal material for use in applications that require a combination of wear resistance, high strength, and toughness. The uniform, homogeneous distribution of small carbides throughout the microstructure is beneficial for increasing the strength and wear resistance of the steel, while the presence of small amounts of porosity helps to increase the toughness of the material. Additionally, the fine pearlitic matrix provides for good machinability characteristics and ductility.

Overall, the microstructure of AISI 910℃Carburized Steel is well suited for applications that require wear resistance, high strength, and toughness. The homogeneous, uniform carbide distribution provides good wear properties and the presence of tiny amounts of porosity helps to increase the toughness of the material. Additionally, the use of a high-temperature carburizing heat treatment process ensures that the grain size is kept to an ultra-fine level, providing the material with machinability and ductility characteristics that are not seen in other hardened steels.

The metallographic of AISI9106 carbon penetration (AISI9106) gold phase diagram shows Microstructure changes of a sample In a certain thermo-mechanical treatment process. 9106 type steel is a kind of low alloy carburizing steel, usually used in parts with alternating high and low stress, such as shafts, gears and cams.

The sample cut from the AISI9106 carbon penetration gold phase diagram shows three typical characteristics: First, it is composed of a mixture of carbides, carbide-free ferrite, and low-carbon (tempered) martensite. Second, the sample contains a large number of carbide particles, mainly accounting for about 65% of the volume fraction, mainly including Fe3C-(type) cementite, M6C-(type) Cr-rich carbides, and M23C6-type carbides. Third, the edge of ferrite grains is enriched with fine carbide particles.

The hardness of the sample mainly comes from the large volume fraction and strong hardness of the carbides. The matrix of the sample contains ferrite and martensite with different carbon content and different hardnesses, and its hardness is improved by these two factors.

The typical metallographic structure of this sample shows that the thermo-mechanical treatment process of AISI9106 carbon penetration gold phase diagram can effectively improve the wear-resistant properties of this type steel. This is mainly due to the fact that more carbides are distributed in the matrix structure and the grain boundary of ferrite grains. In this way, the wear-resistant properties of this type steel can be significantly improved.