Structural modifications of M35 steel submitted to thermal gradients in plasma reactor

Galvão, Nierlly Karinni de Almeida Maribondo; Costa, B.L.S.; Mendes, Marcio W.D.; Brito, R.A. de; Jr., Caubi Ferreira De Souza; Alves, Clodomiro

doi:10.1016/j.jmatprotec.2007.08.058

Cited by 6 publications

(11 citation statements)

References 6 publications

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“…Following the experimental characterization of the pulsed plasma process and the nitrided austenitic stainless steel AISI 316 samples, the following conclusions have been made: 1) The HPPGDP process was shown to be able to ionize gaseous species to generate argon ions, nitrogen ions and their excited neutrals when the input power was increased to 2.5 -4.5 kW. 16 2) The HPPGDP process was found to result in denseenergetic ion bombardment on the high potential biased samples that contributed to forming of high concentration of nitrogen at the sample surface and pronounced plasma induced heating as the same sample surface to create a mechanism for fast nitrogen diffusion into the treated sublayer. 3) At the applied input power of 3.0 kW, Ar to N2flow ratio of 1:2 and total pressure of 1.33 Pa, the steel surface temperature rose with increase time before it stabilized at 420 0 C. Fast plasma nitriding of > 10 µm/hour was achieved for either the one hour nitriding process during which it was started at room temperature, or the three hour nitriding process during which it was also started at room temperature but stabilized at about 420 0 C after one hour.…”

Section: Discussionmentioning

confidence: 99%

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Effect of Nitriding Time on the Structural Evolution and Properties of Austenitic Stainless Steel Nitrided Using High Power Pulsed DC Glow Discharge Ar/N2 Plasma

Yang

Kitchen

Luo

et al. 2016

J. Coat. Sci. Technol.

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A high power pulsed DC glow discharge plasma (HPPGDP) system was employed to perform fast nitriding of AISI 316 austenitic stainless steel in Ar and N2 atmosphere. In-situ optical emission spectroscopy and Infrared pyrometer measurements were used during the plasma nitriding to investigate the effect of dynamic plasma on the nitriding behaviour. SEM and EDX, XRD, Knoop indentation, and tribo-tests were used to characterize microstructures and properties of the nitrided austenitic stainless steel samples.HPPGDP produced high ionization of both Ar and N2in the plasma that corresponded to dense ion bombardment on the biases steel samples to induce effective plasma surface heating and to form high nitrogen concentration on the biased steel surfaces, and therefore fast nitriding (> 10µm/hour) was achieved. Various phases were identified on the nitrided stainless steel samples formed from a predominantly a single phase of nitrogen supersaturated austenite toa multi-phase structure comprising chromium nitride, iron nitride and ferrite dependent on the nitriding time. All the nitrided AISI 316 austenitic stainless steel samples were evaluated with high hardness (up to 17.3 GPa) and exceptional wear resistance sliding to against hardened steel balls and tungsten carbide balls.

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Section: Discussionmentioning

confidence: 99%

“…These can be exploited to ensurethe treated surfaces havespecific properties and microstructures. Another role, plasma surface heating ,has also been widely recognised [14][15][16][17] , buthas not been studied as extensivelyin the history of plasma surface engineering.…”

Section: Introductionmentioning

confidence: 99%

Effect of Nitriding Time on the Structural Evolution and Properties of Austenitic Stainless Steel Nitrided Using High Power Pulsed DC Glow Discharge Ar/N2 Plasma

Yang

Kitchen

Luo

et al. 2016

J. Coat. Sci. Technol.

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“…A explicação dada para esse fenômeno foi a fusão local de partícula do pó, produzida pelos picos térmicos gerados, e a consequente percolação nos poros internos, aumentando assim a porosidade na superfície. A literatura mostra que, dependendo da configuração do plasma, o efeito de gradiente térmico pode ser mais acentuado 5 . Quando a característica geométrica de uma descarga luminescente convencional (configuração cátodo planar) é modificada para configuração de cátodo oco, a taxa de ionização é aumentada em mais de 100 vezes, gerando um plasma com alta taxa de colisão 6 .…”

Section: Introductionunclassified

Novo método para determinação da temperatura de corpos imersos em plasma

Leal¹,

Souza²,

Alves³

2014

RBAV

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RESUMOQuando um sólido é imerso em plasma, dois tipos diferentes de transferência de energia ocorrem: por radiação e por colisão de partículas. No primeiro caso, a energia é transferida de maneira uniforme e paralela à superfície. No segundo caso, ela é transferida para as vizinhanças das micro-regiões onde os picos térmicos são ABSTRACTWhen a solid is immersed in plasma, two different types of energy transfer occurs: by radiation and collision of particles. In the first case, the energy is transferred evenly and parallel to the surface.In the latter case , it is transferred to the neighborhood of micro areas where thermal spikes are generated. In order to study these two effects , discs parallel to the samples made of AISI M35, whose hardness values are strongly temperature sensitive, were used as micro thermal sensors. By correlating hardness to temperature, it was possible to obtain the thermal profile of AISI M35 steel discs treated by plasma. It has been found that parallel disks with layers quenched by plasma had both surfaces (internal and external) of the containment that were not present in the furnace tempering resistive discs. Furthermore, it was found that discs with higher thermal gradients in plasma when annealed, were treated in the hollow cathode configuration with a pressure of 2 mbar and thermocouple at 550°C as the reference.

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“…Os picos térmicos por sua vez, provocarão aquecimentos pontuais de alta intensidade modificando localmente a estrutura do material (6) . Tem-se que a intensidade da porosidade na superfície do material varia de acordo com os parâmetros dos sistemas tais como pressão e configuração de eletrodos (7) . A camada do material afetada por bombardeamento foi denominada como zona de afetada pelo bombardeamento -ZAB (7) .…”

Section: Introductionunclassified

“…Tem-se que a intensidade da porosidade na superfície do material varia de acordo com os parâmetros dos sistemas tais como pressão e configuração de eletrodos (7) . A camada do material afetada por bombardeamento foi denominada como zona de afetada pelo bombardeamento -ZAB (7) . Em tratamentos térmicos de materiais maciços a ZAB apresenta-se como uma microestrutura distinta do resto da amostra, e na sinterização de materiais porosos essa camada apresenta-se com uma porosidade maior que o resto da estrutura do material (7) .…”

Section: Introductionunclassified

Sinterização por plasma de arcabouços porosos da liga Ti-Sn-Nb2O5

Macêdo

Daudt

et al. 2014

RBAV

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Structural modifications of M35 steel submitted to thermal gradients in plasma reactor

Cited by 6 publications

References 6 publications

Effect of Nitriding Time on the Structural Evolution and Properties of Austenitic Stainless Steel Nitrided Using High Power Pulsed DC Glow Discharge Ar/N2 Plasma

Effect of Nitriding Time on the Structural Evolution and Properties of Austenitic Stainless Steel Nitrided Using High Power Pulsed DC Glow Discharge Ar/N2 Plasma

Novo método para determinação da temperatura de corpos imersos em plasma

Sinterização por plasma de arcabouços porosos da liga Ti-Sn-Nb2O5

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