Plasma Carburizing of Sintered Pure Iron at Low Temperature

Lamim, Thiago de Souza; Bernardelli, Euclides Alexandre; Binder, Cristiano; Klein, Aloı́sio Nelmo; Maliska, A.M.

doi:10.1590/1516-1439.306514

Cited by 10 publications

(7 citation statements)

References 23 publications

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“…A imagem de MEV para esta amostra mostra a presença de uma camada com 0,45 µm + 0,02 µm que de acordo com o resultado de DRX é formada por cementita. Esse resultado também foi observado por [4] em seus estudos sobre a cementação de amostras de ferro puro sinterizadas sob as mesmas condições. A formação dessa fina camada de cementita deve estar relacionada a baixa solubilidade do carbono no ferro alfa que é cerca de 0,0025% em peso a 500 °C.…”

Section: Resultados De Mev E Drxunclassified

“…A análise de prova de hipótese e estimativa de variâncias entre as durezas de topo da amostra base e da amostra CE nos faz aceitar que ambas são estatisticamente idênticas com 95% de probabilidade. Este resultado já foi observado por [4] e segundo [9] acredita-se que isto seja proveniente do fato de se tratar de uma camada muito fina de cementita (0,45 µm + 0,02 µm), que é um composto muito duro, sobre um substrato dúctil, o que levaria à quebra da camada cementada e à ocultação da sua dureza pela dureza do substrato. Para eliminar os efeitos do substrato na medição de dureza, determinou-se que a razão entre a profundidade de indentação e a espessura da camada da amostra deve estar dentro de uma faixa de valor critico que varia de 0,07 a 0,2 [9].…”

Section: Resultados De Microdurezaunclassified

“…O uso de descargas elétricas para o tratamento superficial apresenta vantagens em relação aos métodos convencionais como a redução do consumo de gás e energia, maior uniformidade da camada depositada e a redução do tempo de tratamento. A temperatura na qual foram realizados os tratamentos de cementação (500 o C) também dão continuidade a trabalhos realizados por [4] Lamim, o qual estudou a cementação em ferro puro sinterizado em baixas temperaturas visando aplicações onde perdas dimensionais deveriam ser evitadas. Este trabalho tem como objetivo principal avaliar modificações estruturais e microestruturais das camadas obtidas no aço AISI 1005 submetido a diferentes tratamentos de superfícies.…”

Section: Introductionunclassified

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Tratamentos Termoquímicos De Superfície Por Plasma No Aço Aisi 1005

Damin¹,

Maliska²,

Binder³

et al. 2018

ABM Proceedings

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ResumoEste trabalho apresenta uma nova abordagem sobre o emprego sequencial dos tratamentos termoquímicos de superfície utilizando a tecnologia de plasma. No trabalho são avaliados tratamentos de superfície, individuais e sequenciais, de nitretação/cementação. Os tratamentos foram realizados no campo ferrítico com o objetivo de manter as tolerâncias dimensionais. Amostras de aços AISI 1005 foram tratadas em descarga luminescente anormal sendo realizados ciclos únicos de cementação e nitretação e também ciclos conjuntos de nitretação + cementação. Todos os tratamentos foram realizados a 500°C com um tempo de patamar de 3 horas para cada tratamento. A composição da mistura gasosa variou de acordo com o tratamento: nitretação -5%N 2 + 95%H 2 ou 3%N 2 + 97%H 2 ; cementação -5%CH 4 + 95%H 2 . A caracterização microestrutural das amostras foi realizada por microscopia óptica e MEV além de difração de raios-X. Análises de microdureza também foram realizadas. As analises de raios-X mostraram que ocorre a estabilização de uma camada de cementita nos tratamentos de cementação. Nas amostras nitretadas em atmosfera contendo 5% de N 2 foi observada a presença de camada de compostos. Já em atmosferas contendo 3% de N 2 não houve a formação da camada de compostos. A maior profundidade de endurecimento foi obtida para a amostra nitretada + cementada. Palavras-chave: Tratamentos termoquímicos sequenciais; Plasma; Caracterização microestrutural. SURFACE THERMOCHEMICAL TREATMENTS BY PLASMA IN AISI 1005 STEEL AbstractThis paper presents a new approach on the sequential use of surface thermochemical treatments by plasma technology. Single and sequential treatments of nitriding/carburizing are evaluated in this work. The treatments were performed in the ferritic field with the objective of maintaining the dimensional tolerances. AISI 1005 steel samples were treated in an abnormal glow discharge being carried out only carburizing, nitriding, ferritic nitrocarburizing cycles and also sequential cycles of nitriding + carburizing. All treatments were conducted at 500 ° C with a hold time of 3 hours for each treatment. The composition of the gas mixture varied with the treatment: nitriding -5%N 2 + 95%H 2 or 3%N 2 + 97%H 2 ; carburizing -5%CH 4 + 95%H 2 . The microstructural characterization of the samples was carried out by optical and scanning electron microscopy in addition to X-ray diffraction. Microhardness tests were also performed. The X-ray analysis showed the stabilization of a cementite layer in carburizing treatment. In the nitrided samples in atmosphere containing 5% N 2 , it was observed the presence of a compound layer. Already in atmosphere containing 3% N 2 was no formation of a compound layer. The greater depth of hardening was obtained in samples nitrided + carburized.

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Section: Resultados De Mev E Drxunclassified

Section: Resultados De Microdurezaunclassified

Section: Introductionunclassified

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Tratamentos Termoquímicos De Superfície Por Plasma No Aço Aisi 1005

Damin¹,

Maliska²,

Binder³

et al. 2018

ABM Proceedings

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“…Generally, for carbon steels, this treatment occurs normally above 900 °C. However, for pieces that require high dimensional and geometric controls, the use of the high temperatures used in the carburizing treatment becomes a problem, as it leads to a loss of dimensional control 9 . Carburizing treatments at low temperatures has been developed, as described in [10][11][12][13] , for stainless steels to avoid sensitization above 450 °C in these materials, and also for sintered pure iron and automobile gears, again, both to ensure dimensional control 9,14 .…”

Section: Introductionmentioning

confidence: 99%

“…However, for pieces that require high dimensional and geometric controls, the use of the high temperatures used in the carburizing treatment becomes a problem, as it leads to a loss of dimensional control 9 . Carburizing treatments at low temperatures has been developed, as described in [10][11][12][13] , for stainless steels to avoid sensitization above 450 °C in these materials, and also for sintered pure iron and automobile gears, again, both to ensure dimensional control 9,14 . Furthermore, the literature contains some studies describing plasma carburizing at low temperatures as a method to produce surface layers of pure cementite [15][16][17][18] .…”

Section: Introductionmentioning

confidence: 99%

AISI 1005 Steel Plasma Treated by Different Thermochemical Surface Treatments

et al. 2016

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To modify the surface structure of AISI 1005 steel and its properties without any dimensional loss, different plasma surface treatments were performed at low temperatures (500 °C) in this study. The samples were subjected to single plasma treatments including: nitriding (N5% and N3%), carburizing (CE) and ferritic nitrocarburizing (NC) and to duplex treatments of nitriding followed by carburizing (N5%+CE and N3%+CE) and ferritic nitrocarburizing followed by carburizing (NC+CE). The gas mixture used for these treatments was varied as follows: nitriding (5%N 2 +95%H 2 and 3%N 2 +97%H 2 ), carburizing (5%CH 4 +95%H 2 ) and ferritic nitrocarburizing (5%N 2 +1.5%CH 4 +93.5%H 2 ). A microstructural characterization of the samples was carried out using optical and scanning electron microscopy in addition to XRD analysis. Microhardness testing was also performed. The XRD analysis showed a stabilization of the outermost cementite layer for all of the carburizing treatments. The results show that a greater hardness increase was achieved for the nitriding treatment as well as a more regular compound layer. However, a greater depth of hardening was obtained in samples with NC+CE and N5%+CE, which extended to the hardened depth to 800 μm.

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Tribologically induced nanostructural evolution of carbon materials: A new perspective

Neves,

Araya,

Salvaro

et al. 2023

Friction

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Carbon-based solid lubricants are excellent options to reduce friction and wear, especially with the carbon capability to adopt different allotropes forms. On the macroscale, these materials are sheared on the contact along with debris and contaminants to form tribolayers that govern the tribosystem performance. Using a recently developed advanced Raman analysis on the tribolayers, it was possible to quantify the contact-induced defects in the crystalline structure of a wide range of allotropes of carbon-based solid lubricants, from graphite and carbide-derived carbon particles to multi-layer graphene and carbon nanotubes. In addition, these materials were tested under various dry sliding conditions, with different geometries, topographies, and solid-lubricant application strategies. Regardless of the initial tribosystem conditions and allotrope level of atomic ordering, there is a remarkable trend of increasing the point and line defects density until a specific saturation limit in the same order of magnitude for all the materials tested.

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Plasma Carburizing of Sintered Pure Iron at Low Temperature

Cited by 10 publications

References 23 publications

Tratamentos Termoquímicos De Superfície Por Plasma No Aço Aisi 1005

Tratamentos Termoquímicos De Superfície Por Plasma No Aço Aisi 1005

AISI 1005 Steel Plasma Treated by Different Thermochemical Surface Treatments

Tribologically induced nanostructural evolution of carbon materials: A new perspective

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