Austenite
Mostrando 1-12 de 145 artigos, teses e dissertações.
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1. Characterization of Austenite Decomposition in Steels with Different Chemical Concepts and High Potential to Manufacture Seamed Pipes for Oil and Gas Industry
This work presents the characterization of austenite decomposition kinetics in two steels during continuous cooling considering non-deformed austenite grains. Two different chemical concepts of steels were evaluated: low carbon - high manganese and a relatively new concept based on low carbon - low manganese - high niobium contents. Dilatometric experiments,
Mat. Res.. Publicado em: 21/10/2019
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2. Proposição de um Modelo Empírico para Determinação das Temperaturas Críticas Durante Resfriamento Contínuo em Zonas Termicamente Afetadas de Aços IF Soldados pelo Processo TIG
Resumo Aços IF são amplamente empregados na indústria automobilística. No decorrer das aplicações de soldagem, eles passam pela transformação de fase austenita (γ) → ferrita (α) que ocorre por nucleação e crescimento de grão e, em condições isotérmicas, é descrita pela equação JMAK. Todavia, as transformações de fases pós-soldagem ac
Soldag. insp.. Publicado em: 23/09/2019
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3. 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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4. Análise comparativa entre a têmpera e partição versus a têmpera e revenimento para o aço SAE 4340
RESUMO Um novo tratamento térmico tem sido pesquisado recentemente, cuja denominação é têmpera e partição (T&P), com o intuito de criar aços com austenita estável em sua microestrutura. Inicialmente, esse tratamento foi realizado em aços de alto silício, não obstante, seu potencial alcança outros diversos materiais como os de baixa liga contendo
Matéria (Rio J.). Publicado em: 16/09/2019
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5. Avaliação da susceptibilidade de precipitação da fase sigma na soldagem do aço inoxidável duplex SAF2205
RESUMO A soldagem de aços inoxidáveis duplex é uma operação crítica, devido aos ciclos térmicos aos quais o material é submetido, que podem favorecer a precipitação de fases deletérias. Nesse contexto, objetivo dessa pesquisa é analisar a influência da energia de soldagem na susceptibilidade à formação de fase sigma no aço duplex SAF2205. As
Matéria (Rio J.). Publicado em: 16/09/2019
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6. 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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7. Behaviors of Embrittlement and Softening in Heat Affected Zone of High Strength X90 Pipeline Steels
Abstract The embrittlement and softening behaviors in heat affected zone of X90 pipeline steel were studied, and the influence of weld thermal cycle on microstructure and mechanical properties were discussed by combining the effect of peak temperature on the phase transition point (Ar3). Results show that there are embrittlement and softening zones existed i
Soldag. insp.. Publicado em: 15/08/2019
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8. Microstructural Evolution Due to One Thermal Cycle in a Superduplex Stainless Steel ASTM A890/A890M - Grade 6A in the As-Weld and Post-Weld Heat Treatment Conditions
During welding of the superduplex stainless steels are exposed to thermal cycles, allowing precipitation of deleterious phases as well as unbalance as the ferrite and austenite phases. This work analyzed the microstructural changes taking place on a plate ASTM A890/A890M - grade 6A steel submitted to arc welding one welding of pass conducted on a flat surfac
Mat. Res.. Publicado em: 08/08/2019
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9. Effect Of The Application Of Constant And Variable Temperatures at the Overaging Stage in the Mechanical Properties of Trip780 Steel
The effect of the application of constant temperatures (isothermal plateau) and variables (cooling ramp) during the overaging (OA) stage of the continuous annealing cycle in the microstructural characteristics and mechanical properties of a TRIP steel of the class of 780 MPa was investigated. It was simulated six overaging conditions in the equipment Gleeble
Mat. Res.. Publicado em: 15/07/2019
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10. Influence of the Gas Pressure of Plasma Nitriding on the Structural, Mechanical and Tribological Surface Properties of AISI 316L
In this paper, the influence of gas nitriding (80% H2-20% N2) pressure (between 3 and 7 Torr) on the modification of surface properties of AISI 316L stainless steel is examined. The structural, mechanical, tribological and electrochemical properties of the layer produced in disk samples were studied. The samples’ characteristics were determined by scanning
Mat. Res.. Publicado em: 15/07/2019
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11. Effects of Cold Rolling Deformation on Microstructure and Damping Capacity of a Fe-Mn-Cr-Co-Si Alloy
The microstructure evolution of Fe-19Mn-8Cr-1Co-0.2Si (wt.%) alloy and Fe-19Mn (wt.%) alloy during cold rolling and its effect on the damping capacity of the two alloys were investigated. It was shown that the damping capacity of the two alloys was enhanced significantly owing to the deformation-induced ε-martensite and stacking faults. The Fe-19Mn-8Cr-1Co-
Mat. Res.. Publicado em: 11/07/2019
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12. Nitretação a plasma da junta soldada do aço inoxidável super duplex SAF 2507
RESUMO Os aços inoxidáveis superduplex (AISD) apresentam em sua microestrutura as fases ferrita e austenita, de modo a conciliar boas propriedades mecânicas e de resistência à corrosão. Estes materiais possuem grande aplicação na indústria de extração de petróleo e na petroquímica. Quando estão sujeitos a estas aplicações, os dutos de AISD so
Matéria (Rio J.). Publicado em: 20/05/2019