Metallographic diagram of 45 steel (950 ℃ solid boronizing 6h)

Ferritic Observed in 45 Steel After 6 Hours at 950 °C Heat Treatment

Ferritic steel is a type of steel that is widely used in various fields due to its properties. It is known for its strength, ductility, and stability in extreme conditions. The composition of ferritic steel can vary widely depending on its application, but as a general rule, it is composed of iron, carbon, and chromium. In this article, we will discuss the microstructure of 45 steel after 6 hours of heat treatment at 950 °C.

45 steel is a type of ferritic steel that is mainly used in construction applications. It is characterized by a high degree of plasticity and relatively high tensile strength. The heat treatment of 45 steel is critical to achieve the desired properties. Heat treatment is the process of heating and cooling the material to produce a desired property. During heat treatment, the microstructure of the material is altered.

A sample of 45 steel was heated to 950 °C and then held at this temperature for 6 hours. After heat treatment, the sample was cooled to room temperature. The microstructure of the sample was examined using a metallurgical microscope and the results are presented in the micrograph shown.

The micrograph shows that the sample consists of ferrite, a soft and ductile form of iron, and pearlite, a form of ferrite with some of the harder and more brittle cementite. In addition, small globular-shaped cratons with a dark center are visible. These regions most likely consist of manganese sulfides, which are formed when the sulfur content of the sample exceeds the solubility limit of iron. The presence of manganese sulfides is usually associated with the formation of carbides during heat treatment.

The micrograph also shows that the sample has undergone some grain growth during heat treatment. This can be seen in the increased size of some of the grains, indicating that they have grown at the expense of smaller ones. This grain growth is generally beneficial, as it can reduce the likelihood of localized deformation or failure in the material.

Overall, the micrograph suggests that the 45 steel sample has undergone successful heat treatment. The sample consists of a mixture of ferrite and pearlite, and the formation of manganese sulfides indicates that the sulfur content of the sample is high. In addition, some grain growth has occurred, which is beneficial for improving the mechanical properties of the material.

45 steel (solid solution boron treatment at 950℃ for 6 hours) metallographic sample description

The metallographic sample of 45 steel (solid solution boron treatment at 950℃ for 6 hours) was observed under the metallographic microscope. The sample has a surface with a width of 30 micrometers. It is orange-yellow in the center and dark gray on the edge. It is composed of pearlitic matrix and fine martensite.

The martensite distributed in Pearlitic matrix gradually, the size of martensite is mainly 0.1~1μm. The structure of martensite is as thin and thin as thin plate, and one face is smooth, the other face is honeycomb structure, there is a large number of small needle-shaped carbides in the boundary of martensite. The surface of carbide is covered with a large number of small black spots, which is the result of the reaction between carbon and atmosphere.

The Pearlite matrix composed of a large number of ferrite laths and cementite with different thicknesses. Most of the cementite is dark gray with a thickness of about 0.01-0.05 μm, a few of them are thick and dark gray, with a thickness of 0.3-0.5 μm. The ferrite laths are mainly white, with a thickness of 0.15-0.35 μm. The boundary between ferrite laths and cementite is clear, and the angle between them is 90°.

In conclusion, due to the boron solid solution treatment, a large number of fine martensite is generated in the matrix, and the fine carbide is unevenly distributed on the matrix, which further increases the hardness of the material.