scholarly journals Kappa Carbide Precipitation in Duplex Fe-Al-Mn-Ni-C Low-Density Steel

Crystals ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 1261
Author(s):  
Jaka Burja ◽  
Barbara Šetina Batič ◽  
Tilen Balaško
Keyword(s):  
Induction Furnace ◽  
Carbide Precipitation ◽  
Vacuum Induction Furnace ◽  
Low Density ◽  
Transportation Industry ◽  
Cast State ◽  
Cast Sample ◽  
B2 Phase ◽  
Increasing Temperature ◽  
Kappa Carbide

The microstructural evolution of a Fe-Mn-Al-Ni-C low-density steel was studied. The lightweight low-density steels are a promising material for the transportation industry, due to their good mechanical properties and low density. The base microstructure of the investigated steel consists of ferrite and austenite. Thermo-Calc calculations showed the formation of an ordered BCC (body-centred cubic) B2 phase below 1181 °C and kappa carbides below 864 °C. The steel was produced in a vacuum induction furnace, cast into ingots and hot forged into bars. The forged bars were solution annealed and then isothermally annealed at 350, 450, 550, 650, 750, and 850 °C. The microstructure of the as-cast state, the hot forged state, solution annealed, and isothermally annealed were investigated by optical microscopy and scanning electron microscopy. The results showed the formation of kappa carbides and the ordered B2 phase. The kappa carbides appeared in the as-cast sample and at the grain boundaries of the isothermally annealed samples. At 550 °C, the kappa carbides began to form in the austenite phase and coarsened with increasing temperature.

scholarly journals Evolution of Microstructure during Isothermal Treatments of a Duplex-Austenitic 0.66C11.4Mn.9.9Al Low-Density Forging Steel and Effect on the Mechanical Properties

Metals ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 214
Author(s):  
Idurre Kaltzakorta ◽  
Teresa Gutierrez ◽  
Roberto Elvira ◽  
Pello Jimbert ◽  
Teresa Guraya
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Mechanical Strength ◽  
Grain Boundaries ◽  
Automotive Industry ◽  
Carbide Precipitation ◽  
Water Quenching ◽  
Low Density ◽  
Evolution Of Microstructure ◽  
Kappa Carbide

In the last decades, low-density steels for forging have increasing interest in the automotive industry, and good mechanical properties are required for their real application. This paper describes the results obtained for a 0.66C11.4Mn9.9Al duplex austenitic low-density steel after applying a set of isothermal treatments at different combinations of time and temperature, aimed to promote kappa carbide precipitation, and improve the mechanical properties obtained with a water quenching treatment. The effects of the different isothermal treatments on the microstructure and on the mechanical properties have been analyzed and compared to those obtained from a quenching heat treatment. We found that isothermal treatments in the range temperature between 550–750 °C promoted the profuse precipitation of coarse kappa carbides at grain boundaries, which dramatically reduced the ductility of the alloy, whereas a traditional quenching treatment resulted in a better combination of ductility and mechanical strength.

On the Mechanical Milling of the AlCuFe Icosahedral Phase with Water

2014 ◽  
Vol 793 ◽  
pp. 23-27
Author(s):  
C. Patiño-Carachure ◽  
J. Luis López-Miranda ◽  
F. de la Rosa ◽  
M. Abatal ◽  
R. Pérez ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Milling Time ◽  
Induction Furnace ◽  
Icosahedral Phase ◽  
Quasicrystalline Phase ◽  
X Ray Diffraction ◽  
Cast Sample ◽  
X Ray ◽  
Transmission Electron ◽  
Icosahedral Quasicrystalline

In this investigation the Al64Cu24Fe12 alloy was melted in an induction furnace and solidified under normal casting conditions. The as-cast sample was subject to a heat treatment at 700 oC under argon atmosphere in order to obtain the icosahedral quasicrystalline phase in a monophase region. Subsequently, the icosahedral phase was milled for different times and water added conditions. The pre-alloyed and milled powders were characterized using scanning electron microscopy, X-Ray diffraction, and transmission electron microscopy. The experimental results showed that the icosahedral phase is sensitive to the reaction between water and aluminum of the quasicrystalline alloy to generate hydrogen. As the milling time and the amount of water are increased, the embrittlement reaction of the alloy is accentuated releasing more hydrogen.

Utilization of scrap for production of steel 000Kh18N12 in the vacuum induction furnace

Metallurgist ◽  
1974 ◽  
Vol 18 (7) ◽  
pp. 526-527
Author(s):  
N. P. Pozdeev ◽  
Al. G. Shalimov ◽  
A. B. Sergeev ◽  
R. F. Maksutov ◽  
I. V. Khalyakin
Keyword(s):  
Induction Furnace ◽  
Vacuum Induction Furnace

Obtaining of Ni Base Intermetallic Alloys by Solidification Control

2007 ◽  
Vol 23 ◽  
pp. 283-386
Author(s):  
Mariana Lucaci ◽  
Radu L. Orban ◽  
M. Lazarescu ◽  
Stefania Gavriliu ◽  
Magdalena Lungu ◽  
...  
Keyword(s):  
Chemical Composition ◽  
Directional Solidification ◽  
Induction Furnace ◽  
Vacuum Induction Furnace ◽  
Surface Chemical ◽  
Intermetallic Alloys ◽  
Surface Chemical Composition ◽  
Master Alloys ◽  
Solidification Control ◽  
Cylindrical Samples

Directional solidification techniques have been applied to produce Ni based intermetallic alloys with preferentially oriented columnar crystals extended along the complete length and parallel to the solidification direction. Enhanced ductility is expected from such alloys. In this paper we present the research results concerning the application of this technique to some complex Ni3Al- Fe-B alloys obtained from compacted mixtures of elemental powders. The corresponding master alloys have been obtained in a vacuum induction furnace by the known Exo-Melt process [1]. The directional solidification of these alloys was subsequently performed on cylindrical samples, at two solidification rates, 30 and 15 mm/h. The influence of the rate and composition used on the dimensional variations, densities, microstructure, constituent phases and lattice parameters, as well as on the surface chemical composition have been documented and are presented in the paper.

scholarly journals An Atom Probe Study of Kappa Carbide Precipitation and the Effect of Silicon Addition

2014 ◽  
Vol 45 (5) ◽  
pp. 2421-2435 ◽  
Author(s):  
Laura N. Bartlett ◽  
David C. Van Aken ◽  
Julia Medvedeva ◽  
Dieter Isheim ◽  
Nadezhda I. Medvedeva ◽  
...  
Keyword(s):  
Atom Probe ◽  
Carbide Precipitation ◽  
Silicon Addition ◽  
Kappa Carbide

Research on Smelting Vanadium Steel by Silicothermic Reduction Direct Alloying with V2O5

2012 ◽  
Vol 476-478 ◽  
pp. 164-169
Author(s):  
Wei Xiang Wang ◽  
Zheng Liang Xue ◽  
Sheng Qiang Song ◽  
Ping Li ◽  
Zhi Chao Chen
Keyword(s):  
High Temperature ◽  
Thermodynamic Analysis ◽  
Induction Furnace ◽  
Tube Furnace ◽  
Vacuum Induction Furnace ◽  
Medium Frequency ◽  
Carbon Tube ◽  
Silicothermic Reduction ◽  
Direct Alloying

The basic thermodynamic analysis of silicothermic reduction during direct alloying to smelting vanadium steel with V2O5 was discussed in this paper. The high-temperature carbon tube furnace and medium frequency vacuum induction furnace were used to study the phase compositions of the reduction products and the change law of the yield of vanadium when V2O5 was reduced by ferrosilicon. The research shows that the main phases of the silicothermic reduction products were VSi2、FeVO4 and Ca2SiO4 under the condition of using CaO to restrain the volatile of V2O5. Yield of vanadium was gradually improved with the increase of ferrosilicon during the direct alloying. The yield of vanadium in the steel is as high as 95.25% when the addition of ferrosilicon is 35%.

Fabrication, Thermo-Mechanical Processing and Characterization of a Ti-6% Al-1.5% V-1.0 Mo-0.5% Zr-0.1% C Alloy with Addition of Ru and Modifications of Small Amounts of V and Mo

MRS Advances ◽  
2019 ◽  
Vol 4 (57-58) ◽  
pp. 3097-3104
Author(s):  
Bayron Santoveña ◽  
Arnoldo Bedolla-Jacuinde ◽  
Francisco V. Guerra
Keyword(s):  
Mechanical Characteristics ◽  
Induction Furnace ◽  
Small Variation ◽  
Critical Conditions ◽  
Protective Atmosphere ◽  
Vacuum Induction Furnace ◽  
Micro Hardness ◽  
Microstructure Modification ◽  
Corrosive Environments

ABSTRACTPseudo-α or near-α titanium alloys are being widely used in the power generation industry due to their stability at high temperature service, good mechanical characteristics and corrosion resistance. Particularly Ti-6% Al-1.5% V-1.0Mo-0.5% Zr-0.1% C alloy is mainly used in turbines components, heat exchangers and pipes for steam conduction, among others; these are subjected to critical conditions of temperature, abrasion and corrosive environments. A good performance of such devices depends on the chemistry and of the material processing story.Effects on microstructure and wear resistance with the addition of Ru and small variation of V and Mo amounts in the Ti-6% Al-1.5% V-1.0Mo-0.5% Zr-0.1% C alloy were analyzed. Three different alloys were melted in a vacuum induction furnace with a cooled copper skull under an argon protective atmosphere for this studyFour alloys were melted “Alloy 1” Ti-6% Al-1.5% V-1.0Mo-0.5% Zr-0.1% C-0.3% Ru, “Alloy 2” Ti-6%Al-0.5%V-1.6%Mo-0.5%Zr-0.1% C-0.3% Ru, “Alloy 3” Ti-6%Al-2.2%V-0.5%Mo-0.5%Zr-0.1%C-0.3%Ru. After melting, all alloys were homogenized at 1200°C for two hours, followed by hot rolling above β transition temperature with a reduction of 50% in thickness.All alloys were analyzed by using scanning electron microscopy (SEM) and Vickers Micro hardness (HV). Results shown that Mo and V variations modified the micro hardness by microstructure refinement. In contrast, the addition of Ru showed no microstructure modification.

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