Scandinavian Journal of Metallurgy 

About: Scandinavian Journal of Metallurgy is an academic journal. The journal publishes majorly in the area(s): Slag & Steelmaking. It has an ISSN identifier of 0371-0459. Over the lifetime, 584 publications have been published receiving 6037 citations.

The rôle of vanadium in microalloyed steels

Abstract: The overall objective of the present paper is to review the role of V in microalloyed steels with a particular address as to how it affects microstructural evolution and mechanical properties. Its role in thermomechanical controlled processing (TMCP) is emphasised. The review is largely based on work carried out at the Swedish Institute for Metals Research (SIMR) during the last 25 years, but also includes reference to other relevant, published work. A specific aim is to demonstrate the present scientific knowledge of the subject. Therefore the understanding and interpretation of essential phenomena related to microstructure formation and properties are thoroughly examined, ranging from the influence of microalloying on prevention of austenite grain growth and recrystallisation, to precipitation in ferrite and its effect on strength. Within the well-known thermodynamic database, Thermocalc, a special microalloy database has been developed at SIMR, allowing reliable predictions of phase equilibria and thermodynamic functions for phase transformations in microalloyed steels. A comprehensive account is given of the role of V in the most important processing steps that the microalloyed steels are subjected to, viz. TMCP, continuous casting and welding. Compared to the other microalloying elements, Nb and Ti, V exhibits essential differences. In particular, the solubility of its carbonitrides is much larger and the solubility of its nitride is about 2 orders of magnitude smaller than its carbide, contrary to Nb but similar to Ti. For optimal alloy design and thermomechanical processing, proper allowance must be made for these differences. To reach the maximum ferrite grain refinement, ∼4 μm, repeated recrystallisation in a series of rolling reductions is used in TMCP of V-microalloyed steels, so-called Recrystallisation-Controlled-Rolling (RCR), as opposed to traditional controlled rolling of Nb-steels where heavy rolling at low temperatures in the non-recrystallisation regime is the means of attaining grain refinement. RCR presents some important advantages, in particular a more economical hot rolling practice by allowing low reheating and high finishing temperatures. As compared to Nb, V has certain further advantages as a microalloying element due to its greater solubility in austenite. The tendency for hot cracking of cast slabs is much less pronounced and dissolution of coarse V(C,N) compounds is more easily achieved prior to hot rolling than for the corresponding NbC. It is demonstrated that the relatively large solubility of V(C,N) and the much lower solubility of VN than VC makes V an eminent choice for strong and easily controllable precipitation strengthening. A corollary of the difference in VN and VC solubilities is that N becomes an essential microalloying element in V-steels, because it largely determines the density of V(C,N) precipitation and thereby the degree of precipitation strengthening. Moreover, since pure ferrite dissolves more N than C, the total N-content of the steel is normally dissolved in the ferrite before V(C,N) precipitation, whereas only a fraction of the C-content, given by the austenite/ferrite or ferrite/ cementite equilibrium, is dissolved in ferrite. Hence, by precise additions of N, this circumstance facilitates the control of V(C,N) precipitation strengthening.

Dynamic studies of the tensile deformation and fracture of pearlite using high-resolution 200-KV sem

Abstract: Dynamic studies of the tensile deformation and fracture of pearlite using high-resolution 200-KV sem

Thermophysical properties of solid and liquidInconel 718 Alloy

Abstract: Enthalpy, resistivity, density, specific heat capacity, and normal spectral emissivity as a function of temperature of Inconel 718 alloy were measured by a fast resistive pulse heating technique up into the liquid phase, thus obtaining data on thermal conductivity and thermal diffusivity. The high-speed measurements are compared with results of quasistatic measurements of specific heat obtained by differential-scanning calorimetry and expansion measurements by dilatometry.

A thermodynamic database for Ni‐base superalloys

Abstract: A thermodynamic database has been developed for Ni-base superalloys. Following the CALPHAD procedure, it is based on the assessment of thermodynamic behaviour of the relevant constituting sub-syste ...

The assessment of thermodynamic parameters in the Al2O3‐Y2O3 system and phase relations in the Y‐Al‐O system

Abstract: Thermodynamic parameters for solid and liquid phases in the Al 2 O 3 -Y 2 O 3 system are assessed using new calorimetric measurement for the YAG (Y 3 Al 5 O 12 ), YAP (YAlO 3 ) and YAM (Y 4 Al 2 O 9 ) phases. The calculated phase diagram of the Al 2 O 3 -Y 2 O 3 system is in reasonable agreement with experimental data. According to the calculations, the YAP phase melts congruently and is stable down to the low temperatures, while the YAM phase disproportionates to a mixture of YAP and Y 2 O 3 phases at temperatures below 1385 K. The calculated entropy of the YAG phase 300.1 J/(mol.K) is between 2 experimentally determined values 284.8 and 349.1 J/(mol K). However, the difference between calculated and experimental values exceeds uncertainty limits of adiabatic calorimetry data. The enthalpies of melting for the YAG and YAP phases calculated in this study are in reasonable agreement with DTA measurements. The calculated enthalpy of melting for the YAG phase is not consistent with estimates based on solution calorimetric data. New independent measurement of the standard entropy and enthalpy of melting are desirable for the YAG, YAM and YAP phases. The liquidus surface and isothermal section at 2000 K for ternary Al-Y-O system are calculated in this study.