HVOF thermal spray process produces coatings with low porosity and oxide content, as well high substrate adhesion. Small variations on the parameters of can generate different characteristics properties, which also is chemical composition depended alloy. FeMnCrSi alloy a cavitation resistant class material great potential for deposition use. The main goal this article to study influence some deposition, standoff distance, powder feed rate carrier gas pressure three alloys. experimental...

Abstract: Hydraulic runners are susceptible to failures by cracks or wear erosion, corrosion, cavitation. The modern fabricated in carbon steel and martensitic stainless steel. Arc welding processes normally do the repair of eroded areas, cracked parts. Each material type needs specific criteria, procedures, precautions guarantee their success prevent future issues, like recurrence reduction useful life runner modifications original material. Wear-resistant coatings applied thermal spray...

Several techniques can be used to improve surface properties. These involve changes on the chemical composition (such as alloying and welding processes) or microstructure, such hardening melting. In present work melting with a 3kW CO2 cw laser was done alter features of an AISI 304 stainless steel. Microstructure characterisation by optical scanning electron microscopy. Vickers Knoop microhardness tests evaluated mechanical after Phase transformation during rapid solidification is analysed discussed.

Thermally sprayed coatings are employed for many purposes, as corrosion protection, wear resistance improvement, to high temperatures, and others. The coating performance depends on its morphology, which is composed by splats, pores, oxide inclusions, entrapped unmelted or resolidified particles. In arc spray process (ASP), the heat source electric obtained from contact of two consumable metallic wires with different potentials, carrier gas compressed air. velocity, dimensions, thermal...

The necessity to reduce time and maintenance costs in electrical energy generation turbines promotes the development of new materials processes recover cavitated areas. Nowadays, different automated welding process have been studied, mainly plasma-transferred arc (PTA) substitution fluxed core (FCAW). PTA presents as its main advantages: low dilution, a narrow heat-affected zone excellent stability; however, few cavitation resistant alloys are developed for this process. This paper aims...

The present study aimed to produce and characterize FeNbC coatings deposited on AISI 1020 steel using flame spray process (FS) evaluating the influence of powder granulometry, standoff distance, feed rate substrate preheating. FS parameters variations with different properties. Taguchi experimental design based in L9 orthogonal array ANOVA statistical analysis were performed. Coating morphology was evaluated scanning electron microscopy (SEM) energy dispersive spectroscopy (EDS), phases...

ASTM A743-CA6NM é um aço inoxidável martensítico muito utilizado na fabricação de turbinas hidráulicas devido a sua elevada tenacidade, entretanto apresenta restrições com relação à regiões recuperadas por soldagem. Diferentes técnicas deposição tem sido aplicadas o intuito reduzir ou eliminar tensão residual. A revestimentos resistentes cavitação outra forma importante aumentar vida útil destes componentes. O objetivo deste trabalho avaliar influência do tipo e intensidade corrente refusão...

Thermally sprayed coatings rely on mechanical anchoring as the main bond mechanism, which depends previous surface preparation of substrate. In this work, alumina grit was used and reused to blast surfaces in order evaluate its influence granulometry, roughness, cleanliness, coating adhesion strength upon reuse. SEM images illustrate difference grain sizes EDS quantify contamination abrasive with substrate elements after each Different parameters roughness were chosen for characterisation...

A necessidade de diminuição dos tempos parada e custos manutenção turbinas geradoras energia elétrica tem motivado o desenvolvimento novos materiais processos recuperação áreas cavitadas. Atualmente diferentes automatizados soldagem vêm sendo estudados, principalmente a por plasma arco transferido, PTA (plasma transferred arc), em substituição à FCAW (flux cored arc welding). O processo apresenta como principais vantagens baixa diluição, estreita zona termicamente afetada, excelente...

RESUMO A oxidação de parte dos elementos químicos que compõem o aço inoxidável duplex durante a aplicação como revestimento pelo processo aspersão térmica chama arame altera relação entre os equivalentes cromo e níquel, modo se torna dificultada previsão da microestrutura final do utilizando-se diagramas constitucionais existentes Schaeffler. O pré-aquecimento substrato favorece deposição camada para as partículas aspergidas, mas também pode contribuir alteração Creq./Nieq.. Este trabalho...

A ferrita delta é considerada uma fase indesejável na microestrutura dos aços inoxidáveis martensíticos haja vista a mesma poder influenciar no desempenho da resistência à fadiga, tenacidade e corrosão sob-tensão. Sendo assim, o objetivo deste trabalho foi investigar efeito soldagem plasma pulsada sobre distribuição quantidade de em um aço inoxidável supermartensítico. Para tal foram obtidos cordões por meio fusão superficial amostra supermartensítico alta liga utilizando corrente...

Abstract Cavitation erosion is a common phenomenon that occurs in hydraulic turbine blades and result mass loss. Welding the most technique used to recover geometrical profile of these cavitation eroded blades, however it known tensile residual stress can develop. The development manufacture process could reduce or eliminate level will contribute for longer service life this component. It aimed study evaluate mechanism Fe- Mn-Cr-Si-Ni arc thermally sprayed coating. Coatings were analyzed by...

O pentóxido nióbio (Nb2O5), com o seu ponto alto de fusão pode ser uma escolha para aplicação em ambientes temperaturas elevadas que são propícias à corrosão, e, quando misturado alumínio podem trazer alternativas redução da corrosão e desgaste ou degradação a altas dos materiais metálicos. Este trabalho teve por objetivo avaliar os revestimentos aço galvanizado aspersão térmica pelo processo chama pó nióbio/alumínio proporções diferentes posteriormente aplicá-los ensaio polarização...

It is known that application areas of plastics can be enlarged by imparting special features such as higher electrical and thermal conductivity surface metallization these materials. Still, there are very limited studies on the metal deposition polymeric substrates spray process due to various limitations problems associated with this aspect, although some reports available fabrication characterization bonding layers using low melt temperature With background, study was taken up objectives...

AbstractDelta ferrite is considered an undesirable phase in the microstructure of martensitic stainless steels, given its power to influence performance fatigue strength, toughness and corrosion under stress. This study aimed investigate effect pulsed plasma welding on distribution amount delta a supermartensitic steel (SMSS). Weld beads were obtained by surface melting sample SMSS alloy using conventional current. Then, microstructural characterization was performed, particular via...