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Materials Used in the Production of Small Weapons
Published in Jose Martin Herrera Ramirez, Luis Adrian Zuñiga Aviles, Designing Small Weapons, 2022
Jose Martin Herrera Ramirez, Luis Adrian Zuñiga Aviles
α-Fe transforms to the γ-iron (γ-Fe) phase, named austenite, at 912°C. γ-Fe has a face-centered cubic (FCC) structure. It is also a solid solution of carbon in FCC Fe, with a maximum content of 2.14 wt% C at 1147°C. Austenite is a nonmagnetic phase. γ-Fe transforms to δ-iron (δ-Fe), named δ-ferrite, at 1394°C. δ-Fe becomes BCC structure again. The maximum content of carbon in δ-ferrite is 0.09 wt% at 1493°C and it melts at 1538°C. This phase has a similar structure as that of α-Fe, but it is of no technological importance due to the high temperature at which it occurs. Iron carbide (Fe3C), named cementite, is a very hard and brittle ceramic phase. It is because of these properties that cementite is used to strengthen cast irons and steels. It has an orthorhombic crystal structure. Cementite is accountable for the great variety of microstructures and properties produced in steels [5]. This phase coexists with the α phase (α + Fe3C) below 727°C and with the γ phase (γ + Fe3C) between 727°C and 1147°C.
Mechanical Working and Rolling Process
Published in N.K. Gupta, Steel Rolling, 2021
Cementite (Fe3C): The intermetallic compound iron carbide (Fe3C) is called cementite. Cementite is from the Latin word ‘Caementum’ (meaning stone chips). This compound has a fixed carbon content of 6.67% C. It is extremely hard and brittle compound.
Microstructural Characteristics of Metals
Published in Vladimir B. Ginzburg, Metallurgical Design of Flat Rolled Steels, 2020
Cementite, or iron carbide is an interstitial compound of iron and carbon with the approximate chemical formula Fe3C that contains 6.69% carbon. When cementite occurs as a phase in steel, the chemical composition is altered by the presence of manganese and other carbide-forming elements.
Investigations of Microstructure and Mechanical Properties of Post-Weld Heat-Treated DP780 Steel TIG Welds
Published in Fusion Science and Technology, 2023
Gopi Krishna C, M. J. Quamar, N. Kishore Babu, Sarath Kumar G V, Bharath Bandi, M. K. Talari
PWHT reduces the hardness in the FZ, HAZ, and BM due to the tempering of martensite. During tempering, carbon from martensite diffuses out of the high-carbon regime and forms cementite (Fe3C). Additionally, the reduction in dislocation density during tempering could also contribute to the decrease in hardness.[29] The weldment subjected to PWHT at 500°C has shown lesser hardness due to the presence of coarse carbides. Azuma et al.[30] have also reported a gradual decrease in hardness with increasing temperatures up to 600°C.