Microscopic modelling of simultaneous two-phase precipitation: application to carbide precipitation in low-carbon steels
نویسندگان
چکیده
A thermodynamically-based precipitation model, employing the classical nucleation and growth theories, has been adapted to deal with simultaneous precipitation of metastable and stable phases. This model gives an estimation of the precipitation kinetics (time evolution of radius and density of precipitates for both phases, as well as the evolution of solute fraction) in a wide range of temperature. Results were successfully compared with an experimental isothermal precipitation diagram (Time /TemperatureTransformation, TTT) from the literature for the precipitation of e carbide and Fe3C in low-carbon steels. # 2003 Elsevier B.V. All rights reserved.
منابع مشابه
Precipitation of molybdenum carbide in steel: multicomponent diffusion and multicomponent capillary effects
Many steels contain substitutional solutes which have a strong affinity for carbon or nitrogen. Such steels can be hardened by heat treatment which induces the precipitation of fine alloy carbides. Examples of such carbides include MX, 2 73 , 6 and 236 , where M stands for a mixture of iron and substitutional solute atoms and X stands for interstitial solute atoms. In practice, the heat treatme...
متن کاملStrengthening of Low-Alloy Hot-Forging Steel with Nano- sized Precipitation
3 IMR KINKEN Research Highlights 2012 IMR KINKEN Research Highlights 2012 To reduce the fuel consumption by automobiles, medium carbon steels for forging parts, such as shafts and connecting rods, must be further strengthened. When carbide-forming elements such as Ti, Nb, and V, are alloyed with carbon steels, a fine dispersion of alloy carbides and large precipitation hardening can be achieved...
متن کاملEffect of NbMo Addition on the Precipitation Behaviour of V Microalloyed Steel during Intercritical Annealing
This paper reports on the precipitation behaviour and microstructural evolution in ~20% cold rolled NbMoV and V single microalloyed low carbon steels during intercritical annealing. The microstructure and precipitation behaviour were studied by optical and scanning/transmission electron microscopy and microanalysis, X-ray diffraction technique and Vickers hardness testing. After intercritical a...
متن کاملAn Analytical Electron Microscopy Study of Paraequilibrium Cementite Precipitation in Ultra-High-Strength Steel
To support quantitative design of ultra-high-strength (UHS) secondary-hardening steels, the precipitation of cementite prior to the precipitation of the M2C phase is investigated using a model alloy. The microstructure of cementite is investigated by transmission electron microscopy (TEM) techniques. Consistent with earlier studies on tempering of Fe-C martensite, lattice imaging of cementite s...
متن کاملInfluence of Tempering on the Microstructure & Properties of Martensite and Bainite developed in a Low-C High-Si Steel
Martensitic and bainitic steels are two types of widely used steels with excellent mechanical behaviors in automatic industry. It’s universally acknowledged that asquenched martensite possesses poor ductility and impact toughness, which should be tempered before putting into application. During tempering, as-quenched martensite changes from a hard and brittle microstructure to more ductile and ...
متن کامل