Secondary Austenite
Mostrando 1-11 de 11 artigos, teses e dissertações.
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1. Effect of Sigma Phase Precipitated at 850 °C on Corrosion Behaviour of UNS S82441 Duplex Stainless Steel
ABSTRACT Duplex stainless steels (DSS) are alloys with binary microstructure consisting of ferrite (δ) and austenite (γ), combining high mechanical properties and corrosion resistance by pitting and stress corrosion, due to the two phases austenite/ferrite. However, the formation of secondary and intermetallic phases, during solidification processes, heat
Matéria (Rio J.). Publicado em: 16/09/2019
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2. Effect of Nitrogen Addition to Shielding Gas on Cooling Rates and in the Microstructure of Thin Sheets of Duplex Stainless Steel Welded by Pulsed Gas Tungsten Arc Welding Process
The effect of the nitrogen content in the shielding gas and its effect on temperature distributions at the welded zone of thin sheets of duplex stainless steel have been evaluated. The duplex stainless steels have many features due to unique microstructural combination of austenite and ferrite grains. The phase balance can be easily shifted depending on the
Mat. Res.. Publicado em: 26/08/2019
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3. Sigma Phase in Superduplex Stainless Steel: Formation, Kinetics and Microstructural Path
The superduplex stainless steels (SDSS) are widely used in chemical, oil and gas industries, to pipelines and storage material facilities. In welding process or working in temperature elevated, secondary phases may appear in the form of precipitates, as the sigma phase (σ) which is an intermetallic compound. This compound is harmful to the properties of ste
Mat. Res.. Publicado em: 09/01/2017
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4. Influence of Deleterious Phases Precipitation in the Corrosion Resistance Measured by Double Loop Electrochemical Polarization Reactivation Test in Superduplex Stainless Steel
This work investigates the influence of deleterious phases precipitation on the corrosion resistance of two wrought superduplex stainless steels UNS S32750 with similar composition, but different grain sizes. Isothermal treatments were carried out to introduce different amounts of deleterious phases, such as chi (χ), sigma (σ) and secondary austenite (γ2)
Mat. Res.. Publicado em: 2015-08
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5. Deleterious phases precipitation on superduplex stainless steel UNS S32750: characterization by light optical and scanning electron microscopy
Deleterious phases precipitation in superduplex stainless steels is the main concern in fabrication by welding and hot forming of this class of material. Sigma, chi and secondary austenite phases are considered deleterious phases because they produce negative effects on corrosion resistance. Besides, sigma and chi phases also promote strong decrease of tough
Materials Research. Publicado em: 2010-09
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6. Estudo da influência das temperaturas de austenitização nas propriedades mecânicas do ferro nodular austemperado a partir da zona crítica
In the present work the influence of austenitizing temperature on mechanical properties Austempered Ductile Iron from intercritical austenitizing temperature ranges was investigated. A heat treatment for development of material with improved mechanical properties for application in suspension parts is shown. Samples of alloyed ductile iron with a fully ferri
Publicado em: 2009
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7. Influência dos tratamentos térmicos e tratamentos criogênicos na tenacidade do aço rápido AISI M2. / Influence of the heat treatments and cryogenic treatments on the toughness of the AISI M2 high speed steel.
In this work the toughness of the AISI M2 high speed steel heat treated by conventional and cryogenic routes has been evaluated. The toughness was evaluated through un-notched impact samples and 3 points bending cylindrical samples. The heat treatments were carried out in a vacuum furnace using nitrogen quenching with 6 bar of pressure. The conventional rout
Publicado em: 2008
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8. The influence of chemical composition of high-speed steels on the wear during cutting and erosion tests
The paper presents the results of investigations of the 5% cobalt and 2% molybdenum additions in the W-Mo-V and W-V high-speed steels of the 9-2-2, 11-2-2 and 11-0-2 types with economically designed chemical composition on the wear mechanism during cutting and erosion tests. The 5% cobalt addition results in increasing the secondary hardness effect by 1.6 to
Journal of the Brazilian Society of Mechanical Sciences and Engineering. Publicado em: 2003-04
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9. Precipitação de fases intermetálicas e austenita secundária na ZAC de soldagens multipasse de aços inoxidáveis duplex. / Intermetallic phases and secondary austenite precipitation at the multipass welding HAZ of duplex stainless steels.
Duplex stainless steels (DSS) have excellent mechanical and corrosion properties. Many researches have been developed regarding the weldability of these alloys. There are some phase transformations that take place during the welding process, which may impair the welded joint behavior. High temperature heat-affected zone (HTHAZ) microstructures were simulated
Publicado em: 2001
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10. Efeito do tamanho do grão austenítico na cinética e na morfologia do produto da reação bainítica de um ferro fundido nodular austemperado. / Effect of austenite grain size on the morphology and kinetics of the bainitic reaction of an austempered ductile iron.
The effect of austenite grain size on the kinetics and the morphology of the bainitic reaction in an austempered ductile iron (ADI) has been investigated, Three austenite grain sizes were produced: GG (coarse grain), GH (medium grain) and GR (fine grain), The GR condition was obtained by the rapid austenitization of martensitic microstructures The secondary
Publicado em: 1991
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11. Efeitos de carbono, cromo e molibdenio na solidificação de ferros fundidos brancos com alto teor de cromo
The ternary Fe-Cr-C diagrams, as applied to the of high Cr white Cast Iron, were reviewed. Solidification A model was proposed for the solidification sequence .and for the main microconstituints characteristics of these alloys containing or not molybdenun.Solidification experiments were performed on 30 mm diameter samples. The austenite and eutectic arrest t
Publicado em: 1986