As molten iron cools past its freezing point of 1538 °C, it crystallizes into its δ allotrope, which has a body-centered cubic (bcc) crystal structure. As it cools further to 1394 °C, it changes to its γ-iron allotrope, a face-centered cubic (fcc) crystal structure, or austenite....
It is significant that the sides of the face-centred cube, or the distances between neighbouring lattices in the fcc arrangement, are about 25 percent larger than in the bcc arrangement; this means that there is more space in the fcc than in the bcc structure to keep foreign (i.e., ...
23 properties of iron and their changes during the bcc–fcc transition have been calculated. The calculations show that the properties, such as: the Grüneisen parameter, the thermal expansion coefficient, and the specific heat are only slightly changed during the bcc–fcc transition. The modulus ...
J. ( 1981c ) Magnetic properties and microstructures associated with the shock induced transformation of fcc iron to bcc iron . In Shock Waves and High-Strain-Rate Phenomena in Metals (eds. M. A.Meyers and L. E.Murr ), pp. 779 – 793 . Plenum Publishing Corp., New York, New York,...
8e). These relatively wide Ni-poor lamellae are bounded by thin, Ni-rich fcc γ-Fe (taenite). The solid-state nucleation and diffusive growth process by which kamacite grew at slow cooling rates from taenite previously nucleated from melt is quite well understood. The 1-atm Fe-Ni phase...
(fcc) at 1394 °C, when it is known as γ-iron, or austenite. At 912 °C the crystal structure again becomes bcc as α-iron, or ferrite, is formed, and at 770 °C (the Curie point, Tc) the iron becomes magnetic. As the iron passes through the Curie temperature there is no ...
(BCC)crystalstructure.Asitcoolsfurtheritscrystalstructurechangestofacecentrecubic(FCC)at1394°C,whenitisknownasgamma-iron,oraustenite.At912°CthecrystalstructureagainbecomesBCCasalpha-ironalsoknownasferrite,isformed,andat770°C(theCuriepoint(http:\/\/en.wikipedia\/...
Pure iron exists in two crystal forms, one body-centred cubic (bcc) (α-iron, ferrite) which remains stable from low temperatures up to 910°C (the A3 point), when it transforms to a face-centred cubic (fcc) form (γ-iron, austenite). The γ-iron on remains stable until 1390°C,...
First-principles calculations of the local magnetic moments for 4d impurities in bcc and fcc iron hosts are performed. The molecular cluster discrete variational method (DVM) is used to obtain the electronic structure in spin-polarized calculations in the framework of the local approximation of the ...
We also apply the MSLP to study the magnetic effect of mesoscopic scale dislocation loops in iron at finite temperature, which cannot be achieved using DFT and MD, or using other available machine-learned spin-lattice potentials. Results Magnetic states in BCC and FCC structures Table 1 The ...