17 documents found, page 1 of 2
Application of low Ms temperature consumable to dissimilar welded joint
Saraiva, Daniel Lucena; Béreš, Miloslav; Silva, Cleiton Carvalho; Nunes, Cristiana dos Santos; Silva, Jean Jefferson Moraes daThe welding of dissimilar joints is very common in systems used in oil exploration and production in deep sea waters. Commonly involves welding of low carbon steel pipes with low alloy steel forgings both with inner Inconel clad. The forged steel part undergoes a process of buttering with Inconel or carbon steel electrode before the weld of the joint. The buttering process is followed by a process of residual s...
An assessment of biomedical CoCrMo alloy fabricated by direct metal laser sinte...
Girão, Daniel de Castro; Béreš, Miloslav; Jardini, André Luiz; Maciel Filho, Rubens; Silva, Cleiton Carvalho; Siervo, Abner deCoCrMo alloys have been used for several decades in implantable devices due to their favourable mechanical properties, low wear rate in addition to good biocompatibility and high corrosion resistance. These alloys are conventionally produced via casting and/or forging route, however additive manufacturing techniques being recently employed in their fabrication. In this work, CoCrMo samples were produced by dire...
Simulations in multipass welds using low transformation temperature filler mate...
Novotný, Ladislav; Abreu, Hamilton Ferreira Gomes de; Miranda, Hélio Cordeiro de; Béreš, MiloslavTransient thermal and residual stress fields in flux-cored arc welds were examined using a finite element (FE) model. Experimental multipass welds were produced using both conventional and low transformation temperature (LTT) filler metals. Temperature-dependent material properties and both convective and radiant heat loss boundary condition have been considered in the FE model. The effects of the transformatio...
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...
Deformation-induced martensitic transformation in Co-28Cr-6Mo alloy produced by...
Antunes, Luiz Henrique Martinez; Quintero, John Jairo Hoyos; Andrade, Tathiane Caminha; Sarvezuk, Paulo Willian Carvalho; Wu, Leonardo; Ávila, J.A.The wear resistance of the biomedical low-carbon Co-28Cr-6Mo (wt.-%) alloy is primarily determined by the onset and magnitude of the face-centered cubic to hexagonal close-packed deformation-induced martensitic phase transformation. In metal-on-metal joint bearings, local plastic deformation occurs on the surface and in the subsurface regions. This can cause deformation-assisted structural changes in the materi...
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....
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...
Hydrogen embrittlement of ultra high strength 300 grade maraging steel
Santos, Luis Paulo Mourão dos; Béreš, Miloslav; Bastos, Ivan Napoleão; Tavares, S.S.M.; Abreu, Hamilton Ferreira Gomes de; Silva, M.J. Gomes daSlow strain rate tests were conducted in air and aqueous 0.6 M NaCl at −1.2 VSCE environments to investigate hydrogen embrittlement (HE) of ultra high strength 300 grade maraging steel. The results showed that the samples were susceptible to HE in different levels after submitted to heat treatments. Moreover, the over-aged samples were more resistant to HE than the peak-aged ones. Reverted austenite contained o...
Application of low Ms temperature consumable to dissimilar welded joint
Saraiva, Daniel Lucena; Béreš, Miloslav; Silva, C. C.; Nunes, C. S.; Silva, J. J. M.; Abreu, Hamilton Ferreira Gomes deThe welding of dissimilar joints is very common in systems used in oil exploration and production in deep sea waters. Commonly involves welding of low carbon steel pipes with low alloy steel forgings both with inner Inconel clad. The forged steel part undergoes a process of buttering with Inconel or carbon steel electrode before the weld of the joint. The buttering process is followed by a process of residual s...