Simultaneous plasma nitriding and ageing treatments of precipitation hardenable plastic mould steel

Oliveira, Sandro D.; Tschiptschin, André Paulo; Pinedo, Carlos Eduardo

doi:10.1016/j.matdes.2006.03.011

Cited by 41 publications

(22 citation statements)

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“…5 present a shift to higher, noble potential (E corr ) values and lower corrosion currents (i corr ), considering the Tafel slopes of the nitrided pieces compared with those untreated (see Table II) calculated with the software incorporated into the work station. It should be noted that the better electrochemical performance obtained in sample (1) is due to a higher content of the ε phase compared to other nitrided samples according to [7]. These gures are in good agreement, though, to these published about 4140 low alloy steel [13].…”

Section: Resultssupporting

confidence: 82%

“…The thin monophase γ -Fe 4 N compound layer * corresponding author; e-mail: regulo.lopez@inin.gob.mx becomes more wear resistant compared to the ε-Fe 2−3 N monophase one because of its ductility [6]. However, the situation is reversed when corrosion is an issue showing the ε-Fe 2−3 N is more corrosion resistant than γ -Fe 4 N as a consequence of its crystalline structure and higher nitrogen content [7]. The eects of a maximised content of nitrides have also been studied [2].…”

Section: Introductionmentioning

confidence: 99%

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Nitriding of 4140 Annealed Low Alloy Steel in RF Plasma

et al. 2013

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The annealed low alloy 4140 steel samples have been nitrided for dierent treatment periods (16 h) in an RF inductive plasma discharge with very low bias voltage (≈ 400 V). The resulting nitrided layer has been observed by means of an optical microscope whereas the nitride phases have been characterised by X-ray analysis. The corrosion response, assessed by the potentiodynamic tests in the 3.5% NaCl solution, presents both higher noble potential values and lower corrosion rates when compared with the untreated sample. The Vickers microhardness tests values show an appreciable increment compared to that of the untreated sample. The process is characterized by a high overall eciency because similar average Vickers tests values were obtained, no matter for how long the treatment was extended. Likewise, the scanning electron micrographs conrmed no appreciable size evolution of the compound layer microstructure at dierent times of treatment.

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Section: Resultssupporting

confidence: 82%

Section: Introductionmentioning

confidence: 99%

Nitriding of 4140 Annealed Low Alloy Steel in RF Plasma

et al. 2013

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“…15,16) In another work, Öztürk et al 17) reported an effectiveness of plasma nitriding conditions in improving the tribological and corrosion properties of X36CrMo17 injection mold steel. Oliveira et al 18) indicated the nitriding and aging of precipitation hardening plastic mold steel can be achieved simultaneously in the same treatment cycle and found that the corrosion resistance was enhanced after nitriding. However, for a deeper understanding of precipitation hardening tool steels the effects of plasma nitriding on erosion by solid particle and erosioncorrosion by slurry are essential, but very little work has been done on these aspects.…”

Section: )mentioning

confidence: 99%

Improving the Erosion and Erosion–Corrosion Properties of Precipitation Hardening Mold Steel by Plasma Nitriding

Lan

Wen

2012

Mater. Trans.

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In this study plasma nitriding of precipitation hardening mold steel has been carried out at 470, 500 and 530°C for 12 h in order to achieve good erosion and erosioncorrosion resistance. The microstructure, phase present and microhardness profiles of unnitrided and nitrided layers were examined. The influence of plasma nitriding on the erosion and erosioncorrosion resistance of the tested steel was investigated using a jet solid particle erosion tester and a rotated slurry erosioncorrosion tester.The results indicate that the surface properties of the plasma nitrided layers in terms of hardness, erosion wear, and erosioncorrosion resistance are highly dependent on nitriding temperature, and all three plasma surface treatments can significantly improve the surface hardness and effective enhance their erosion resistance under dry erosion. The erosioncorrosion resistance in 20 mass% SiC particles/3.5% NaCl slurry can be effectively improved 48, 65 and 68% by plasma nitrided at 470, 500 and 530°C, respectively. The erosion rate decreases with increasing surface hardness and obeys a power function ( _ E / H Àn ) with exponent of 1.047. However, the correlation between erosioncorrosion rate and hardness does not obey any power functions of the exponent in the range of 11.5 due to the complexity of the interaction between erosion and corrosion.

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“…Assim, o uso do endurecimento superficial de Nitretação é uma opção de uso corrente [3][4][5] e tem sido estudada amplamente para diferentes aços inoxidáveis [6], incluindo os aços inoxidáveis PH [7][8][9]. Levando em consideração que a nitretação é aplicada em componentes envelhecidos para os quais a resistência mecânica é fundamental para o seu desempenho, a nitretação não deve alterar as propriedades do substrato, sob pena de inviabilizar a posterior utilização de um componente, mesmo que sua superfície esteja com dureza elevada [10]. É sabido que a nitretação sob plasma DC possui restrições para a obtenção de uma camada homogênea em decorrência dos efeitos de borda ou de sombra.…”

Section: Introductionunclassified

Nitretação Sob Plasma Por Tela Ativa E Plasma Direto/Dc Do Aço Inoxidável Endurecível Por Precipitação Tipo 17-4 Ph

Vitoi¹,

Magnabosco²,

Pinedo³

et al. 2018

ABM Proceedings

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ResumoA nitretação do aço inoxidável endurecível por precipitação do tipo 17-4PH foi estudada comparativamente pelos processos de Plasma-DC e de Tela Ativa. Os resultados mostram que os dois processos são eficientes em promover a formação da camada nitretada de elevada dureza superficial, cerca de 1300 HV0,025. Entretanto, diferenças importantes são observadas. No processo de Plasma-DC a camada nitretada é composta, além da martensita acicular saturada em nitrogênio, de nitretos de ferro e cromo precipitados pela supersaturação. No processo de Tela Ativa a precipitação de nitretos de cromo é praticamente suprimida e predominando os nitretos de ferro. Esta diferença na sequência de precipitação de nitretos é inferida como sendo causada pela oferta de nitrogênio. Em Plasma-DC a oferta de nitrogênio é suficiente para a precipitação do nitreto de cromo, o que não ocorre em Tela Ativa. A maior profundidade de camada e de endurecimento transversal confirma a maior difusão de nitrogênio em Plasma-DC. Ainda, em ambos os processos a dureza de partida do substrato envelhecido é preservada após o ciclo de nitretação. Palavras-chave: Aço 17-4 PH; Nitretação sob plasma; Tela ativa; Endurecimento. DC-DIRECT AND ACTIVE SCREEN PLASMA NITRIDING OF 17-4 PH STAINLESS STEEL AbstractPlasma nitriding of 17-4PH was studied by DC-Plasma and Active Screen processes. Both processes are effective for increasing the surface hardness up to 1300 HV0.025. However, differences in the nitrided case characteristics are observed. In the Plasma-DC process the diffusion zone has iron and chromium nitrides precipitation while in the Active Screen process massive iron nitride precipitation is observed. Such difference in the precipitation behavior is a consequence of the nitrogen inlet rate. For the Plasma-DC the nitrogen inlet rate is higher than for the Active Screen, and enough to allow chromium nitride precipitation. Nitriding depth is higher on DC-Plasma compared to Active Screen. For both processes the aged substrate hardness is not impaired after the surface treatment.

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Simultaneous plasma nitriding and ageing treatments of precipitation hardenable plastic mould steel

Cited by 41 publications

References 4 publications

Nitriding of 4140 Annealed Low Alloy Steel in RF Plasma

Nitriding of 4140 Annealed Low Alloy Steel in RF Plasma

Improving the Erosion and Erosion–Corrosion Properties of Precipitation Hardening Mold Steel by Plasma Nitriding

Nitretação Sob Plasma Por Tela Ativa E Plasma Direto/Dc Do Aço Inoxidável Endurecível Por Precipitação Tipo 17-4 Ph

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Simultaneous plasma nitriding and ageing treatments of precipitation hardenable plastic mould steel

Cited by 41 publications

References 4 publications

Nitriding of 4140 Annealed Low Alloy Steel in RF Plasma

Nitriding of 4140 Annealed Low Alloy Steel in RF Plasma

Improving the Erosion and Erosion&ndash;Corrosion Properties of Precipitation Hardening Mold Steel by Plasma Nitriding

Nitretação Sob Plasma Por Tela Ativa E Plasma Direto/Dc Do Aço Inoxidável Endurecível Por Precipitação Tipo 17-4 Ph

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Improving the Erosion and Erosion–Corrosion Properties of Precipitation Hardening Mold Steel by Plasma Nitriding