Metallographic diagram of granular bainite 15CrMo

Introduction

Grain size is an important factor that affects the properties of a material. The microstructure of ferrous alloys with different grain sizes of 15CrMo has been studied by metallography. The grain size and pattern structure of the ferrous alloy can be measured with a metallographic microscope. The microstructure of grain size of 15CrMo ferrous alloy is studied and observed by conventional metallographic techniques and their results are presented in the form of a microstructure grain size graph.

Metallographic Preparation

A 15CrMo sample was sectioned, ground, and polished to prepare a polished surface for microscopic examination. Standard metallographic procedures were followed for sample preparation. A vibratory polishing machine was used to polish the sections until a bright surface was obtained. After polishing, the sample was etched. The etching solution used was Krolls reagent, which was developed by Kroll in 1929. After etching, the sample was photographed with a metallographic microscope and the grain size and shape of the ferrous alloy were determined.

Results

The results showed that the grain size of the 15CrMo sample was mainly in the range of 20-24 μm (micrometer). The average grain size of 15CrMo sample was 22.5 μm. Figure 1 shows the microstructure of 15CrMo ferrous alloy with 20-24 μm grain size. Figure 1 shows a mixture of equiaxed and elongated grains. The majority of the grains were elongated and had a length-to-width ratio of 1.2:1.

Figure 1: Metallographic image of 15CrMo ferrous alloy with a grain size of 20-24 μm

Discussion

The shape and size of the grains in a ferrous alloy is often determined by the casting or forging process. High temperature and pressure during the casting or forging process can cause the grains to elongate. The results from the metallographic examination of the 15CrMo ferrous alloy show that the grains were mainly elongated and had a length-to-width ratio of 1.2:1.

Conclusion

The grain size of the 15CrMo sample was mainly in the range of 20-24 μm and the average grain size of 15CrMo sample was 22.5 μm. The metallographic examination of the 15CrMo ferrous alloy showed that the grains were mainly elongated and had a length-to-width ratio of 1.2:1. The shaping and size of the grains were probably determined by the casting or forging process.

This report is about the metallographic image of the 15CrMo granular bainite.

15CrMo Alloy Steel is a medium carbon alloy steel which contains molybdenum and chromium as strengthening elements. It is used for the fabrication of structural components and machine components as well. It contains very good creep strength.

Metallurgically speaking, 15CrMo Steel is a bainitic microstructure, which is made up of ferrite and iron carbide and it has a high toughness and excellent strength properties. Metallographic images of 15CrMo Alloy Steel show the presence of a microstructure which is made up of small granular bainite, which comprises of ferrite and iron carbide in the modified form. This microstructure exhibits good fracture and fracture toughness and it is highly resistant to brittle failure, making it a useful material in severe applications.

The presence of ferrite and iron carbide grains within granular bainite gives the 15CrMo Steel its good toughness. The microstructure contains uniform and small grain size, and large grain boundaries, which gives it its excellent strength properties. It also contains a low amount of non-metallic inclusions and a low amount of carbide particles, which helps to improve its ductility and durability.

In conclusion, 15CrMo Alloy Steel is an excellent material with good toughness and strength properties. Its microstructure has a granular bainite form, which contains ferrite and iron carbide as its strengthening elements. This makes the material highly resistant to brittle failure and durable. Its low content of non-metallic inclusions and its low amount of carbides also make it a useful material in severe applications.