Metallographic diagram of 60 steel (annealed at 810°C)

Introduction

A number of studies have been conducted on the subject of the microstructures of AISI 8660 grade steel after heat treatment of 810°C. By conducting these studies, the researchers have been able to determine the various structures of the sample, which is of interest to scientists with a view towards understanding the various processes involved in the formation of microstructures. This paper will take a look at the microstructures of AISI 8660 grade steel after heat treatment of 810°C, in order to better understand the mechanisms of microstructure formation.

AISI 8660 Steel

AISI 8660 is an alloy steel that is characterized by its low carbon content, as well as its mill-hardened and thermally treated properties. It is composed of the elements: iron, chromium, molybdenum, nickel and copper, as well as some small amounts of boron, tin, manganese and phosphorus. This grade of steel is particularly suitable for applications that require strength, ductility and machinability. It is also resistant to wear, impact and fatigue, which helps to make it a favorite amongst manufacturers around the world.

Heat Treatment of 810°C

In order to study the microstructures of AISI 8660, the researchers conducted a heat treatment of the sample at a temperature of 810°C. Following this heat treatment, a series of specimens were prepared and subjected to a metallographic inspection. This allowed them to gather information about the microstructures present in the sample, as well as their properties.

Results

The metallographic examination of the heat-treated AISI 8660 steel revealed a number of microstructures that were typical of this grade of steel. The results were fairly consistent across all of the specimens that were observed. The microstructures were mainly composed of pearlite and ferrite, as well as some martensite, bainite and other non-metallic inclusions. The pearlite was found to be the most abundant feature and was found to have a relatively uniform dispersion throughout the specimen.

Conclusion

Through the metallographic examination of the heat-treated AISI 8660 steel, the researchers were able to learn much about the various microstructures that were present in the sample. The main microstructures found in this sample were pearlite and ferrite, as well as some martensite, bainite and other non-metallic inclusions. The pearlite was found to be the most abundant feature and was found to have a relatively uniform dispersion throughout the specimen. These findings are of great interest to metallurgists and manufacturing professionals, as they can help to better inform the design and application of such materials in industry.

Under the microscope, the microstructure of JIS SCM415 60 steel is analyzed after quenching and tempering at 810℃. The microstructure of the steel consists of granular ferrite, lath martensite, and small amounts of retained austenite and carbide distribution.

The ferrite grains have an average size of about 3.2μm. These ferrite grains are distributed homogeneously and have a pro-eutectoid structure, which is generally composed of ferrite and relatively fine particles distributed at the grain boundary. This indicates that the cooling rate was too slow for dynamic transformation of austenite to martensite.

Lath martensite is present in the center of the grains and is distributed in a small angle to the grain boundary. The martensite is in the form of laths that are parallel to each other and bounded by finely distributed dislocations. The thickness of the laths ranges from 0.3μm to 1.2μm.

Retained austenite is present in the steel in both isolated and block form. The isolated austenite has an average size of about 0.3μm and is finely distributed in the ferrite matrix. The blocks of the austenite are about 0.4 to 0.5μm in size and are mainly distributed at the grain boundaries of the ferrite.

The carbides present in this steel are mainly M23C6 type and are distributed in the matrix of the ferrite grains. These carbides are distantly distributed and have an average size of about 2μm.

Overall, the JIS SCM415 60 steel has good granular structure, appropriate homogeneous distribution of ferrite, lath martensite, and retained austenite, as well as fine and distantly distributed carbides. These characteristics indicate good mechanical properties of this steel.