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Analysis of Deformation Induced Martensite in an AISI 301L Stainless Steel: Mic...
Abreu, Hamilton Ferreira Gomes de; Silva, Marcelo José Gomes da; Herculano, Luís Flávio Gaspar; Bhadeshia, HarryExperiments have been conducted to study the strain induced transformation from austenite to martensite in a metastable AISI 301LN austenitic stainless steel, deformed by uniaxial tension applied along rolling direction. Samples deformed 10 and 20% have shown the presence of α´ martensite phase. Measured pole figures of martensite phase were compared to calculated ones, assuming no variant selection and selecti...
The effect of prior austenite grain size on hydrogen embrittlement of Cocontain...
Silva, Marcelo José Gomes da; Cardoso, Jorge Luiz; Carvalho, Dayane de Sousa; Santos, Luis Paulo Mourão dos; Herculano, Luís Flávio GasparThe effects of the prior austenite grain sizes in hydrogen embrittlement of Co-containing 18Ni 300 maraging steel were studied employing Slow Strain Rate Testing (SSRT) in 0.6 M NaCl electrolyte under simultaneuos cathodic polarization. The material was susceptible to hydrogen embrittlement in all investigated conditions. In addition, the examination of the fractured surface revealed that the presence of hydrog...
Microstructural characterization of grade 300 and grade 350 maraging steels and...
Flórez, Mauro Andrés Cerra; Pereira, Úrsula Cid; Cardoso, Jorge Luiz; Oliveira, Francisco José dos Santos; Araújo, Walney Silva; Ribas, Gemma FargasThe electrochemical behavior of solution-annealed grade 300 and grade 350 maraging steels subjected to two different aging temperatures in an aqueous hydrofluoric acid (HF) medium was evaluated. The microstructural and hardness studies showed the effects of the chemical composition and heat treatments on the material properties. Although it is not possible to observe them, the fine intermetallic composites depo...
Oxidation behavior of Maraging 300 Alloy exposed to nitrogen/water vapor atmosp...
Flórez, Mauro Andrés Cerra; Ribas, Gemma Fargas; Cardoso, Jorge Luiz; García, Antonio Manuel Mateo; Rovira, Joan Josep Roa; Bastos Neto, MoisésAging heat treatments in maraging steels are fundamental to achieve the excellent mechanical properties required in several industries, i.e., nuclear, automotive, etc. In this research, samples of maraging 300 alloy were aged using a novel procedure that combines different steps with two atmospheres (nitrogen and water vapor) for several hours. The oxidized surface layer was chemical, microstructural and microm...
Corrosion behavior of austenitic stainless steels in CO2-saturated synthetic oi...
Cardoso, Jorge Luiz; Mandel, Marcel; Krüger, Lutz; Herculano, Luís Flávio Gaspar; Lima Neto, Pedro de; Silva, Marcelo José Gomes daThe corrosion behavior of austenitic and superaustenitic stainless steels was investigated in carbon dioxide-saturated synthetic oil field formation water using cyclic polarization tests. In order to measure the effect of carbon dioxide pressure, the samples were also exposed in a pressurized medium containing carbon dioxide and synthetic air. For this purpose, tests were performed for long exposure time at 80 ...
The role of microstructure and grain orientations on intergranular cracking sus...
Masoumi, Mohammad; Tavares, Sérgio Souto Maior; Pardal, Juan Manuel; Martins, Tabatta Regihna Brito; Silva, Marcelo José Gomes daThe aim of this work was to investigate the role of crystallographic orientations and grain boundary characteristics as a new approach to controlling the intergranular cracking (IGC) susceptibility. In this respect, hydrogen cathodic charging under two different current densities was carried out on 17–4 pH steel (H900 condition) in order to search for correlations between intergranular corrosion and microstruct...
Influence of reverted austenite on the texture and magnetic properties of 350 m...
Abreu, Hamilton Ferreira Gomes de; Silva, Jean J.; Silva, Manoel Ribeiro da; Silva, Marcelo José Gomes daThe aging temperature to improve magnetic properties in Maraging-350 steel (Mar-350) is limited by the onset of austenite reversion. The traditional process of cooling after aging is to remove the piece from the oven and then to air cool it. The purpose of this research was to characterize the reverted austenite and to investigate the effect of cooling below the martensite start temperature (Ms) on the magnetic...
Texture analysis of deformation induced martensite in an AISI 301L stainless st...
Abreu, Hamilton Ferreira Gomes de; Silva, Marcelo José Gomes da; Herculano, Luís Flávio Gaspar; Bhadeshia, HarryExperiments have been conducted to study the strain induced transformation from austenite to martensite in a metastable AISI 301LN austenitic stainless steel, deformed by uniaxial tension applied along rolling direction. Samples deformed 10 and 20% have shown the presence of α´ martensite phase. Measured pole figures of martensite phase were compared to calculated ones, assuming no variant selection and selecti...
Role of lattice strain and texture in hydrogen embrittlement of 18Ni (300) mara...
Béreš, Miloslav; Wu, Leonardo; Santos, Luis Paulo Mourão dos; Masoumi, Mohammad; Rocha Filho, Francisco Alberto Marreiros da; Silva, C.C. daHydrogen embrittlement causes engineering components to fail unexpectedly. Maraging 300 steel was hydrogen charged and subjected to slow strain rate tensile test until fracture.Electron backscatter diffraction analysis of fractured specimen revealed that cracks initially propagated intergranulary along prior-austenite grain boundaries. When cracks faced martensitic f111ga planes parallel to normal direction (ND...
Efeito da adição de boro na resistência mecânica da liga modelo de aço superfer...
Paiva, Daniele Morais; Silva, Marcelo José Gomes daAços inoxidáveis são ligas metálicas baseadas nos sistemas ferro-cromo e ferro-cromo-níquel, mas podem conter adições de outros elementos de liga tais como molibdênio, manganês, silício, cobre, titânio, nióbio, vanádio e nitrogênio, que alteram as suas microestruturas e propriedades.O aumento do desempenho dos aços inoxidáveis ferríticos é conseguido com teores de Cr acima de 12% e adições de Mo que melhoram a ...