An Investigation of the Microstructure of 1Cr5Mo Steel
The 1Cr5Mo steel is a low-alloy martensitic steel. It has a combination of excellent mechanical properties, weldability, and resistance to oxidation and carburization. This has made it one of the most widely used low-alloy steels. In this paper, we present our investigation of the microstructure of 1Cr5Mo after being subjected to a normalizing heat treatment. The material was examined through optical microscopy, focused ion beam scanning electron microscopy, and X-ray diffraction.
Optical examination of the microstructure of the 1Cr5Mo steel by using a light microscope revealed a typical microstructure of ferrite and pearlite. The ferrite had a lamellar structure, with primary and secondary ferrite grains present in the microstructure. The pearlite had a globular structure, with a high percentage of primary ferrite grains present. Mill scale and other precipitates were also found in the microstructure.
Focused ion beam scanning electron microscopy revealed that 1Cr5Mo steel microstructure underwent a significant change during normalizing heat treatment. The primary ferrite grains decreased in size and changed in shape, while the secondary ferrite grains increased in size. The addition of the precipitates increased the interlamellar spacing, which further reduced the size of the primary ferrite grains.
X-ray diffraction revealed that the precursor phases in the 1Cr5Mo steel microstructure changed upon normalizing heat treatment. The ferrite and pearlite phases transformed to carbides and oxides, which were present in large clusters in the microstructure.
The findings of our investigation show that normalizing heat treatment significantly affects the microstructure of 1Cr5Mo steel. The ferrite and pearlite phases changed in size and shape, while precipitates were formed throughout the microstructure. The transformation of the precursor phases to carbides and oxides further contributed to the changes observed. We expect that further study of 1Cr5Mo steel and its microstructure should lead to a better understanding of its properties and behavior.