23 documents found, page 1 of 3
The effect of pearlite morphology and crystallographic texture on environmental...
Loureiro, Rodrigo de Carvalho Paes; Béreš, Miloslav; Masoumi, Mohammad; Abreu, Hamilton Ferreira Gomes deMechanism of failure by environmentally assisted cracking was extensively investigated in the present work to find the effect of pearlite morphology and crystallographic texture on crack nucleation and propagation sites. The macrotexture analysis revealed that (001) crystallographic texture components parallel to the normal direction was predominant in the investigated sample. Crack nucleated at surface pits an...
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....
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...
Microstructural variations at different distance from the surface in forged 18 ...
Figueiredo, Nathália Cândido; Oliveira, Carlos Augusto Silva de; Masoumi, Mohammad; Abreu, Hamilton Ferreira Gomes deMicrostructure and microtexture of forged 18 Ni C300 maraging steel at different solution annealed temperatures were studied to show strain distribution associated with forged surface distance. Samples were examined by Electron Back-Scattered Diffraction to characterize the microstructural parameters such as grain sizes, grain orientation and boundary characteristics throughout the forged samples at the surface...
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...
Texture and grain boundary study in high strength Fe–18Ni–Co steel related to h...
Masoumi, Mohammad; Santos, Luis Paulo Mourão dos; Bastos, Ivan Napoleão; Tavares, Sergio S.M.; Silva, Marcello J.G. daCrystallographic texture and grain–boundary distribution are introduced as a new method of reducing susceptibility to crack formation and propagation. In this work, slow strain rate tests (SSRT) were performed on fully martensitic ultra-high strength Fe–18Ni–Co steel in 0.6 M NaCl atmosphere at −1.2 VSCE to investigate hydrogen embrittlement (HE). Micro and meso-texture in both crack stricken and crack free reg...
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...
Effect of microstructure and crystallographic texture on the Charpy impact test...
Masoumi, Mohammad; Barros, Isabel Ferreira de; Herculano, Luís Flávio Gaspar; Coelho, Hana Livia Frota; Abreu, Hamilton Ferreira Gomes deThe effect of different solution annealing temperatures on the hardness, impact toughness and crystallographic orientation of high strength martensitic 300 grade maraging steel was investigated. The results showed that the solution annealing temperature has a significant influence on the impact toughness energy because of the engineering of the crystallographic textures. The impact toughness improved with incre...
Study of texture and microstructure evaluation of steel API 5L X70 under variou...
Masoumi, Mohammad; Herculano, Luís Flávio Gaspar; Abreu, Hamilton Ferreira Gomes deThis work studies the influence of different thermomechanical paths on the microstructure and crystallographic texture across the thickness of API 5L X70 pipeline steel manufactured via hot rolling using X-ray diffraction (XRD), scanning electron microscope (SEM), and electron backscattered diffraction (EBSD). The starting materials were controlled hot-rolled at 1000 1C to 44% and 67% reductions and subsequentl...