19 documents found, page 1 of 2
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...
Determination of the sensitized zone extension in welded AISI 304 stainless ste...
Lima Neto, Pedro de; Farias, Jesualdo Pereira; Herculano, Luís Flávio Gaspar; Miranda, Hélio Cordeiro de; Araújo, Walney Silva; Jorcin, Jean-BaptisteExtension of sensitized zone (SZ) in welded AISI 304 stainless steel was determined by two non-destructive electrochemical tests: double loop electrochemical potentiokinetic reactivation technique (DLEPR) and local electrochemical impedance spectroscopy (LEIS). Welding was carried out using the shielded metal arc with two selected welding energies: the first one (0.7kJmm¡1) does not promote the sensitization of...
Kinetics of reverted austenite in 18 wt.% Ni Grade 300 Maraging steel: an in-si...
Santos, Luis Paulo Mourão dos; Béreš, Miloslav; Castro, Mirela Oliveira de; Sarvezuk, Paulo Willian Carvalho; Wu, LeonardoIn this study, we investigated the transformation kinetics of martensite fi reverted austenite in 18 wt.% grade 300 Ni maraging steel. The kinetics was evaluated based on the in situ synchrotron x-ray diffraction data collected during isothermal heat treatment at 570C. The onset of transformation martensite fi reverted austenite was detected after 5 min of aging. The austenite fraction increased as a function o...
Microstructure and Crystallographic texture changes under torsion loading of pe...
Masoumi, Mohammad; Béreš, Miloslav; Herculano, Luís Flávio Gaspar; Loureiro, Rodrigo de Carvalho Paes; Abreu, Hamilton Ferreira Gomes deCold-drawn pearlitic steel strips exhibit a great combination of strength and ductility and are widely used in many engineering applications. Some of these applications require further mechanical conformation for the final use. An analysis of the microstructure and the change in crystallographic texture when strips are subjected to torsion processes necessary for some applications was made in the current study....
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 ...
EBSD study of early fractured phenomena in a 350 grade Maraging steel elbows ex...
Masoumi, Mohammad; Abreu, Hamilton Ferreira Gomes de; Herculano, Luís Flávio Gaspar; Pardal, Juan Manuel; Tavares, Sérgio S.M.; Silva, Marcelo J.G.The effect of grain orientations, boundary characteristics, and crystal effects on the crack formation of a 350 high strength Maraging steel elbows exposed to hydrofluoric acid was investigated in the present research. Tempered low tetragonal martensite and fresh martensite were characterized by scanning electron microcopy. Moreover, no segregation zone and precipitates were found near the crack path. Detail an...
New approach to evaluate a non-grain oriented electrical steel electromagnetic ...
Rebouças Filho, Pedro Pedrosa; Santos, José Ciro dos; Freitas, Francisco Nélio Costa; Rodrigues, Douglas de Araújo; Ivo, Roberto FernandesThe growing global demand for energy makes it necessary to adopt measures ranging from the exploration of new energy sources to the development of technology for machinery and equipment with greater energy efficiency. Non-grain oriented electrical steels are widely used in the construction of rotors and stators that form the core of electric motors, and their microstructures are directly related to its electrom...
Study and classification of the Crystallographic Orientation Distribution Funct...
Ivo, Roberto Fernandes; Rodrigues, Douglas de Araújo; Santos, José Ciro dos; Freitas, Francisco Nélio Costa; Herculano, Luís Flávio GasparThis article discusses a fast and efficient classification of non-grain oriented electrical steel and its electromagnetic efficiency based on the analysis of the images of the Crystalline Orientation Distribution Function (CODF). The study was carried out on samples of a non-grain oriented electrical steel, semi-processed with 1.28% silicon, cold rolled with thickness reductions of 50.0% and 70.0%, and annealed...
Texture study across thickness of API X70 steel after hot deformation and diffe...
Masoumi, Mohammad; Herculano, Luís Flávio Gaspar; Almeida, Arthur Araújo; Béreš, Miloslav; Abreu, Hamilton Ferreira Gomes deIn the present study, the texture heterogeneity across the thickness of API X70 steel subjected to hot deformation and different posttreatments was investigated. X-ray diffraction and electron backscattered diffraction were used to analyze crystallographic orientation and grain boundary distributions at the center and surface layers of specimens. The initial material was rolled at 1000C to 67% reduction; then o...