Cleiton Silva

The oil and gas industry often faces the need to halt the transportation and production of its products for repair operations or to bypass flowlines, resulting in unwanted costs. These costs can be avoided by employing a specialized welding procedure performed during service. However, executing such a technique requires great care due to the presen...

In-situ synchrotron X-ray diffraction experiments were conducted on the pearlitic steel sample with a carbon content of 0.74% by weight. Specimens were subjected to uniaxial loading that induced shear deformation and two-dimensional diffraction patterns were acquired. The evolution of the lattice microstrain and the strain-resolved crystallographic...

In this study, a new method for welding an API 5L X65 steel pipe that is internally clad with Alloy 625 cladding using Alloy 22 and AWS ER100S-G steel was developed. The first and second weld passes were made using Alloy 22 to provide excellent corrosion resistance for the Alloy 625 cladding region. The remaining weld passes were made using 100S-G...

The FSW process parameters for dissimilar welding of AISI 410S and 304L stainless steels were meticulously varied to achieve a combination of excellent surface finish, zero voids, and complete tool penetration. These crucial findings have far-reaching practical implications, providing valuable guidance for the welding industry to attain optimal res...

The FSW process parameters for dissimilar welding of AISI 410S and 304L steels were varied to provide a combination of good surface finish, no voids, and complete tool penetration. These findings have practical implications, as they can guide the welding industry in achieving optimal results. Preliminary tests were performed to analyse the proper p...

Stainless steels are widely used in industry due to their corrosion resistance properties. Ferritic stainless steels are cheaper than austenitic steels because the former do not contain nickel, an expensive alloying element. However, when ferritic stainless steels are used in manufacturing industries, they undergo microstructure transformations tha...

Presenting a low Ductile–Brittle transition temperature compared to other body-centered cubic structural steels, lath martensitic steels, such as 9Ni steels, are the most prominent high-strength steels proposed for low-temperature and cryogenic services. In the past couple of decades, broad access to tools and instrumentation required to map comple...

O presente trabalho avaliou o comportamento microquímico e microestrutural da Zona de Alta Diluição (ZAD) da interface dissimilar de tubos de aço 9Ni soldados, pelo processo MIG/MAG, com a liga Inconel 625. Estes materiais são utilizados em Unidades de Injeção de CO2 (UI-CO2), em reservatórios de petróleo. Para as análises, foram aplicadas técnicas...

9Ni steels have been recently adopted in supercritical CO2 injection systems in deepwater oil fields. The manufacture of these reinjection systems involves multi-pass welding procedures, which produce an Heat-Affected Zone (HAZ) with a high heterogeneity level regarding the microstructural features and the local mechanical properties. An extensive...

Resumen Neste trabalho foi investigada a influência do metal de adição e do tempo de tratamento térmico de envelhecimento sobre a susceptibilidade ao trincamento por corrosão sob tensão (CST) de juntas soldadas do aço inoxidável austenítico AISI 317L em solução aquosa de MgCl2 (43%). Dois tipos de metais de adição (ASW ER317L e AWS ER2209) foram us...

The present work investigated the influence of heat input and aging time on the microstructural characteristics and the mechanical properties of dissimilar AISI 317L austenitic stainless steel welded joints. The AWS ER2209 wire-electrode was used as filler metal, and two different heat input levels were applied (4 and 8 kJ/cm), aiming to verify the...

Friction stir welding (FSW) has been successfully used to join dissimilar materials with advantages such as incipient chemical mixing and positive recrystallization of the microstructure. However, to understand how welding parameters affect the thermal cycle and the material flow around the tool is essential to produce joints without defects. In th...

After continuous annealing process (CAP) at 790°C, 85% of the coils of 50% cold-rolled low carbon microalloyed (LCM) steel did not exhibit yield-strength (YS) on the target range, while the 70% cold-reduced LCM coils did. In this context, the non-isothermal recrystallisation kinetics of ferrite for the above two full-hard LCM steel were investigate...

Friction stir welding (FSW) has been successfully used to join dissimilar materials with advantages such as incipient chemical mixing and positive recrystallization of the microstructure. However, to understand how welding parameters affect the thermal cycle and the material flow around the tool is essential to produce joints without defects. In th...

This study aims to evaluate the weldability of dissimilar welds with the Inconel 625 and the Hastelloy C-276 nickel-based alloys deposited on ASTM A36 and AISI 1045 carbon steel plates. The welds were carried out by the GMAW process and evaluated by the Trans-Varestraint test. The test results were statistically evaluated, and Fusion Zone solidific...

The friction stir weld (FSW) method was developed in 1991 by The Welding Institute (TWI) and is very useful for manufacturing components with low fusion weldability. The success of this relatively new technique is due, in part, to an appropriate combination of some parameters. In order to understand the influence of the parameters such as rotation...

Friction stir welding (FSW) is a solid-state process, where a tool that consists of a shoulder and a pin rotates between the plates to be welded by plastic deformation. This process involves several physical phenomena. To better understand this complex phenomenon, simulations have been performed for a range of maximum viscosity values. The viscosit...

In this study, we investigated the transformation kinetics of martensite → 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 570°C. The onset of transformation martensite → reverted austenite was detected after ~...

The present study discusses the use of the Tandem GMAW process as a technology capable of postponement manufacturing in the production of specific alloys, using different commercially available alloys. The results show that the Tandem GMAW process can be successful applied to produce in-situ alloys for specific purposes by combining different alloy...

In this work, the effect of heat input and aging treatment on the microstructural characteristics and mechanical properties of similar AISI 317L austenitic stainless steel weldments used in the petroleum industry was investigated. The filler metal used was the AWS ER317L electrode at two different heat input levels (4 and 8 kJ/cm) in order to verif...

Resumo Neste trabalho foi investigado da energia de soldagem e do envelhecimento térmico sobre a microestrutura e as propriedades mecânicas de juntas soldadas do aço inoxidável austenítico AISI 317L usado na indústria de petróleo. O metal de adição usado foi o eletrodo AWS ER317L em dois diferentes níveis de energia (4 e 8 kJ/cm). As amostras foram...

CoCrMo 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...

This study aimed to investigate the susceptibility of AISI 410S ferritic stainless steel to intergranular corrosion when friction stir welded (FSW) using the double-loop electrochemical potentiokinetic reactivation (DL-EPR) test. The highest values obtained for the ratio between the reactivation current (I r ) and the activation current (I a ) were...

The welding of dissimilar joints is very common in systems used in oil exploration and production in deep waters. This commonly involves welding low carbon steel pipes with valves, pumps or other pipes, all of them made of alloy steel. Inconel has been used in such welding as filler material; however, this welding is preceded by a process of butter...

It is believed that texture, as the preferred crystallographic orientation of microstructuralfeatures, causes plastic anisotropy, leading to a decrease in formability. Thus, promotingrecrystallization and randomizing crystallographic texture have been the main methodsof increasing formability. The aim of the current study was to improve the tensile...

One of the possibilities of variation of the Tandem GMAW process is the use of out-of -phase current pulse, with the aim of giving greater stability to the voltaic arcs. In some works available in the literature, the authors found results that showed that this effect of out-of -phase current pulse was not significant. Another aspect that is also wi...

The Friction Stir Welding process parameters were varied to provide a combination of an acceptable surface finish, absence of cracks, and full tool penetration. Two levels of rotation speed and axial forces from 10 to 30 kN were applied, whilst keeping the welding speed constant at 1 mm/s. One of the defects analyzed was the production of flashes....

The aim of this work was to evaluate the different phases formed during solidification and after thermal aging of the as-welded 625 nickel-based alloy, as well as the influence of microstructural changes on the mechanical properties. The experiments addressed aging temperatures of 650 and 950 o34 C for 10, 100 and 200 h. The samples were analyzed b...

A commercial API 5L X70 steel plate was subjected to different thermomechanical processes to propose a novel thermomechanical rolling path to achieve improved mechanical properties. Scanning electron microscopy, electron backscatter diffraction, and x-ray texture analysis were employed for microstructural characterization. The results showed that s...

Biomedical cobalt-chromium-molybdenum (Co-Cr-Mo) alloys have been used in the cast or wrought form as prosthetic implant materials for more than five decades. Recently, additive manufacturing techniques are employed to produce parts directly from metal precursor powder with a composition suitable for biomedical applications. In the work present, we...

Dilution is an event that has a great influence on the microstructure and, consequently, in the properties of weld claddings. The present study evaluated the effect of dilution level on the microstructure of the fusion zone of alloy Inconel 686 weld claddings. The claddings were welded by the TIG cold wire feed process. The dilution was calculated...

Quantitative analyses produce important information concerning the microstructural characteristics of materials, which are reflected in the main properties of the materials. The secondary and backscattered electron modes represent the two main techniques most used in scanning electron microscopy, to produce images and, consequently, realize a quant...

Hydrogen 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...

Hydrogen-induced cracking (HIC) causes considerable economic losses in a wide range of steels exposed to corrosive environments. The effect of crystallographic texture and grain boundary distributions tailored by rolling at 850 °C in three different steels with a body-centered cube structure was investigated on HIC resistance. The x-ray and electro...

The microstructural and textural evolution was analyzed during rolling at room temperature to obtain detailed information about the failure behavior in HSLA grade-420 steel. Electron backscatter diffraction measurements were carried out in both non-cracked and cracked areas after cold rolling to find a correlation between microstructural parameters...

In order to improve the mechanical properties of API X70 pipeline steel, a rolling schedule in the recrystallization temperature region associated with a post heat treatment was proposed. Optical and scanning electron microscopy, electron backscattered diffraction, hardness, and tensile tests were carried out to show the effects of microstructure a...

The aim of this work is to evaluate the welding residual stress profile in ASTM A106 Gr. B steel pipes with 4′ diameter and to correlate this profile with the microstructure and hardness of the joint. The results showed that the residual stresses are more uniform for a lower welding heat input. Higher welding heat input causes not only a non-unifor...

The purpose of this work was to improve the resistance of hydrogen-induced cracking in API 5L X70 steel by engineering the crystallographic texture and grain boundary distributions via different rolling temperatures. Hydrogen-induced cracking and electrochemical hydrogen charging tests were carried out in two different conditions: commercially prod...

Dilution and microsegregation are phenomena inherent to claddings, which, in turn, directly affect their main properties. This study evaluated microsegregation in the fusion zone with different dilution levels. The overlays were welded by the TIG cold wire feed process. Dilution was calculated from the geometric characteristics of the claddings and...

The dilution is an event that have a high influence on the microstructure and, consequently, in the properties of weld claddings. The present study evaluated the effect of dilution level on the microstructure of the fusion zone of alloy Inconel 686 weld claddings. The claddings were welded by the TIG cold wire feed process. The dilution was calcula...

Weld overlay with Ni-based superalloys is an important option for industrial applications. New alloys have been developed to assure desirable characteristics such as corrosion resistance. The Inconel 686 superalloy was developed with a higher Cr and Mo content in order to improve its resistance to corrosion. However, information in the literature a...

The objective of the present work was to evaluate the influence of the welding parameters in the formation of defects in weld overlays with nickel-based alloys, and its possible elimination through the correct adjustment of the welding parameters. Coatings were deposited with the nickel-based alloy types Inconel 625, Hastelloy C276 and Inconel 686...

Resumo O presente trabalho visa investigar a microestrutura formada na soldagem dissimilar entre chapas de aços inoxidáveis ferríticos AISI 410S e aços inoxidáveis austeníticos AISI 304L pelo processo friction stir welding. A soldagem foi realizada com o ajuste dos seguintes parâmetros: rotação 450 rpm; velocidade de soldagem de 1,0 mm/s; e força a...

This work aimed to evaluate the mechanical properties of AISI 410S ferritic stainless steel welded by friction stir welding process (FSW), through bending tests, microhardness and tensile. The variation of the parameters was carried out seeking conditions that would result in a combination of acceptable surface finish, absence of cracks and good pe...

This study aimed to investigate the similar welding of AISI 444 ferritic stainless steel by the friction stir welding process (FSW), evaluating axial force for the production of joints without defects. The variation of the parameters was carried out seeking conditions which would determine a combination of acceptable surface finish, absence of crac...

Texture measurements were carried out on API 5L X70 was deformed by cold rolling at room temperature in order to obtain information about a possible crack formation. Special attention was paid to the crack initiation and propagation. Textures were determined by X-ray diffraction (XRD) and electron backscatter diffraction (EBSD), which presented mac...

Secondary phases, such as laves and carbides, are formed during the final solidification stages of nickel-based superalloy coatings deposited during the gas tungsten arc welding cold wire process. However, when aged at high temperatures, other phases can precipitate in the microstructure, like the γ” and δ phases. This work presents an evaluation o...

Este trabalho tem por objetivo estudar a influência do tecimento na soldagem TIG com alimentação de arame frio em único passe visando à aplicação futura em revestimento de ligas de níquel, considerando a análise das características geométricas e diluição, de forma a adequar estes revestimentos para as indústrias do Setor de Petróleo e Gás Natural....

O objetivo do presente trabalho foi avaliar a influência dos parâmetros de soldagem na formação de defeitos na soldagem de revestimentos com ligas à base de níquel, e sua possível eliminação através do correto ajuste dos referidos parâmetros. Para tanto, foram depositados revestimentos com as ligas à base de Ni do tipo Inconel 625, Hastelloy C276 e...

The 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 joi...

The purpose of this study is to evaluate the effectiveness in the contribution of the interpass welding in the microstructures and properties of the dissimilar fusion zones produced with an alloy 625 and API 5L X65 steel pipes. Three multipass welded joints with v-groove, were made under the same welding parameters, therefore, changing only the int...

The aim of this study is to evaluate the microstructure and properties, resulting from the dissimilar welding of Ni-based alloys like Hastelloy C276 and Inconel 625 with ASTM A516 Gr 60 steel, through the deposition of overlays by the TIG welding process with cold wire feed. The results showed that it is feasible to produce coatings with low diluti...

Ni-based alloys are a special class of engineering material with excellent corrosion resistance in harsh environments. However, microstructural changes due to the solidification, may result in solidification cracks and reduction in the corrosion resistance. Knowing the microchemical and microstructural evolutions during the solidification of these...

Secondary phases such as Laves and carbides are formed during the final solidification stages of nickel based superalloy coatings deposited during the gas tungsten arc welding cold wire process. However, when aged at high temperatures, other phases can precipitate in the microstructure, like the γ″ and δ phases. This work presents a new application...

The current study presents some fundamental observations on the effects of the welding heat input in the chemical composition, microstructure, hardness and petroleum corrosion resistance of the fusion zone, formed by the AWS E309MoL austenitic stainless steel covered electrode and the AISI 410S ferritic stainless steel, being a dissimilar welding p...

To extend the life and reliability of pipes and equipment in oil & gas production and processing settings is a continuous demand. These aspects are essentially dependent on corrosion resistant alloys used. In this context, the weld overlay with Ni-based superalloys is a great interesting alternative, since improve the corrosion resistance without i...

The objective of this work was to optimize the operational conditions aiming to deposit weld overlays with a minimal dilution and iron content as low as possible, and a thickness of weld higher than 3 mm just in a single layer. The alloys studied were Inconel 625, Hastelloy C276 and Inconel 686. The ASTM A516 Gr 60 steel was used as substrate. The...

Dissimilar metal welds have large applications in various industrial sectors like oil & gas and nuclear for both joining and overlay. In this sense, the fusion boundary microstructure plays an important role to ensure the integrity of weld overlays. The present investigation aims to evaluate the differences in chemical composition and crystallograp...

Nickel based alloys are a special class of materials for engineering with excellent corrosion resistance for harsh environments and are used in various industries. Among several types of applications, its use like coatings is very interesting due to a significant cost reduction. However, microstructural changes in interface can produce heterogeneou...

Secondary phases such as Laves and carbides are formed during the final stages of solidification of the nickel based superalloy Inconel 625 coatings deposited during the gas tungsten arc welding (GTAW) cold wire process. However, when aged at high temperatures, other phases can precipitate in the microstructure, like the gamma '' and delta phases....

The main objective of this work was to evaluate the combined effect of welding parameters on the level of precipitation of topologically closed-packed phases in Ni-Cr-Mo weld overlays deposited by welding on the C-Mn steel plates. The Taguchi method was employed to planning the experiments. The welds were carried out by GTAW cold wire feed process...

This study evaluated the behavior of different types of austenitic stainless weld metals deposited by electrodes AWS Class E 309, subject to rapid aging, with respect to susceptibility to intergranular corrosion. After welding the samples were subjected to rapid aging at a temperature of 700 ° C with times 1/2h, 1h, 5h and 10h. Later were conventio...

The aim this work is to evaluate the influence of multipass welding heat input on the microstructure and mechanical properties of the heat affected zone (HAZ) of UNS S31803 duplex stainless steel multipass welded joints. The shielded metal arc welding process using as filler metal the AWS E2209-17 covered electrode were employed had been carried th...

The presence of precipitates in metallic materials affects its durability, resistance and mechanical properties. Hence, its automatic identification by image processing and machine learning techniques may lead to reliable and efficient assessments on the materials. In this paper, we introduce four widely used supervised pattern recognition techniqu...

Resumo O presente trabalho avalia a migração de elementos químicos, especialmente o molibdênio, na interface matriz/ precipitado de revestimentos de ligas Ni-Cr-MoW , depositados sobre substrato de aço C-Mn. A caracterização microestrutural foi realizada empregando-se as técnicas de microscopia eletrônica de varredura (MEV), microscopia eletrônica...

Resumo O objetivo deste trabalho foi investigar a influência da preparação metalográfica e das condições do processo de aquisição de imagens sobre a quantificação de fases secundárias através de uma rede neural do tipo perceptron multicamadas. As imagens foram obtidas por microscopia eletrônica de varredura (MEV) a partir de revestimentos de superl...

Duplex and superduplex stainless steels are class of materials of a high importance for engineering purposes, since they have good mechanical properties combination and also are very resistant to corrosion. It is known as well that the chemical composition of such steels is very important to maintain some desired properties. In the past years, some...

Quantitative metallography is a technique to determine and correlate the microstructures of materials with their properties and behavior. Generic commercial image processing and analysis software packages have been used to quantify material phases from metallographic images. However, these all-purpose solutions also have some drawbacks, particularl...