Nitrieren und Nitrocarburieren∗

Spies, H.‐J.

doi:10.3139/105.110182

Cited by 19 publications

(4 citation statements)

References 7 publications

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“…However, current industrial implementations of the PNC technology still are limited in their variation of the carburizing potential as the carbon content within the process is regulated using carbon-containing admixtures to the feed gas. This can lead to oversaturation of the process atmosphere, in turn causing soot production and generation of cementite in the compound layer [3]. So far, process control in industrial applications is based on the operator's empirical experience.…”

Section: Introductionmentioning

confidence: 99%

Spectroscopic study of plasma nitrocarburizing processes with an industrial-scale carbon active screen

Puth

Kusýn

Pipa

et al. 2020

Plasma Sources Sci. Technol.

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The active screen plasma nitrocarburizing technology is an improvement of conventional plasma nitrocarburizing by providing a homogeneous temperature distribution within the workload and reducing soot formation. In this study, an industrial-scale active screen (AS) made of carbon-fibre-reinforced carbon serves as the cathode as well as the carbon source for the plasma-chemical processes taking place. The pulsed dc discharge was maintained at a few mbar of pressure while simultaneously being fed with a mixed gas flow of hydrogen and nitrogen ranging from 10 to 100 slh. Using in situ infrared laser absorption spectroscopy with lead salt tuneable diode lasers and external-cavity quantum cascade lasers, the temperatures and concentrations of HCN, NH3, CH4, C2H2, and CO have been monitored as a function of pressure and total gas flow. To simulate industrial treatment conditions the temperature of the sample workload in the centre of the reactor volume was kept at 773 K by varying the plasma power at the AS between 6 and 8.5 kW. The resulting spectroscopically measured temperatures in the plasma agreed well with this value. Concentrations of the various species ranged from 6 × 1013 to 1 × 1016 cm−3 with HCN being the most abundant species.

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Section: Introductionmentioning

confidence: 99%

Spectroscopic study of plasma nitrocarburizing processes with an industrial-scale carbon active screen

Puth

Kusýn

Pipa

et al. 2020

Plasma Sources Sci. Technol.

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“…Assisted by pulsed dc discharges, plasma nitriding and plasma nitrocarburizing have been employed as surface engineering methods to improve the tribological properties of metal surfaces for several decades. In a variety of applications, the traditional conventional plasma nitriding technique (CPN) has become an industrial standard approach for surface hardening and surface modification [1][2][3][4][5]. These methods are based on thermochemical diffusion processes.…”

Section: Introductionmentioning

confidence: 99%

“…In CPN technology, the standard method is the control of the mass flow of the carbon-containing gases based on traditional recipes combined with the operator's experience. Therefore, even for a low percentage of additional carboncontaining gases, the risk of soot production and cementite precipitation in the compound layer is high [1].…”

Section: Introductionmentioning

confidence: 99%

Spectroscopic investigations of plasma nitrocarburizing processes using an active screen made of carbon in a model reactor

Puth¹,

Hamann²,

Kusýn³

et al. 2018

Plasma Sources Sci. Technol.

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The active screen plasma nitrocarburizing technology significantly reduces the risk of cementite precipitation in the compound layer of nitrocarburized materials and of soot production compared to conventional plasma nitrocarburizing. In a laboratory-scaled plasma nitriding monitoring reactor, PLANIMOR, using an active screen made of carbon, low-pressure pulsed dc N 2 -H 2 plasmas have been studied by infrared laser absorption spectroscopy (IRLAS) techniques. Applying IRLAS, using tunable diode lasers (TDL) and a quantum cascade laser (QCL) as radiation sources, the evolution of the concentrations of eight stable molecular reaction products, C 2 H 2 , C 2 H 4 , CH 4 , HCN, NH 3 , CO, C 2 H 6 , and C 2 N 2 , and of the CH 3 radical, have been monitored. By using the line ratio method, the rotational temperatures of HCN and CO could be determined in a range of 300-400 K and 300-500 K, respectively. Analysing the profile of the CH 3 Q(3-3) absorption line, the gas temperature of this radical, i.e. the temperature in the vicinity of the plasma zone, has been found to range between 400-800 K. The concentrations of the detected molecular reaction products were found to be in the range of 10 12 -10 16 molecules cm −3 with HCN and NH 3 as the most abundant reaction products. Additionally, the respective conversion efficiencies to the product molecules (R C ≈5×10 12 -2×10 16 molecules J −1 ) have been determined for different mixing ratios of N 2 :H 2 in the feed gas and plasma power values. Taking into account the concentrations of all carbon-containing species, a maximum of the carbon combustion of the screen material of up to 96 mg h −1 has been found for a N 2 -H 2 ratio of 1:1 and the highest plasma power of the screen of P screen =106 W.

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“…Bauteile sind oft komplexen tribologischen und korrosiven Beanspruchungen ausgesetzt. Um derartigen Anforderungen gerecht zu werden, kommen für Stähle Kombinationen verschiedener Randschichtbehandlungsverfahren zur Anwendung [22,23]. Zur Kombinationsbehandlung von Gusseisen sind der-zeit nur einzelne Forschungsergebnisse bekannt, wie z.…”

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Potenziale von ausgewählten Randschichtbehandlungsverfahren sowie deren Kombinationen zur Verbesserung des Verschleiß- und Korrosionsverhaltens von Gusseisenwerkstoffen

Buchwalder

Zenker

Fritzsch

et al. 2015

Mat.-wiss. u. Werkstofftech

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Die typischen hohen C-und Si-Gehalte von Gusseisenwerkstoffen und der weiche Graphit limitieren die Behandel-und Beanspruchbarkeit nach dem Nitrieren und der Hartstoffbeschichtung. Wenn die Gusseisenoberfläche vor den genannten Randschichtbehandlungen mittels Elektronstrahls umgeschmolzen wird (Kombinationsbehandlung) und eine harte, graphitfreie ledeburitische Randschicht gebildet wird, dient diese als Stützschicht für die harte und dünne Verbindungs-bzw. Hartstoffschicht.Vergleichende Verschleißtests (Stift-Scheibe) zeigten, dass bei geringen Lasten die Verschleißrate aller Einzel-und Kombinationsbehandlungen auf einem vergleichbar niedrigen Niveau wie der unbehandelte und beschichtete Grundwerkstoff liegen. Bei höheren Lasten kommt das überragende Verschleißverhalten der Kombinationsbehandlungen gegenüber den Einzelbehandlungen voll zum Tragen. Die Bildung defektfreier Randschichten nach der Kombinationsbehandlung resultiert außerdem in einer deutlichen Verbesserung der Korrosionsbeständigkeit in chloridhaltiger Lösung. Im Vergleich zum Grundwerkstoff und den Einzelbehandlungen wurden die relevanten Potenziale zu deutlich positiveren Werten verschoben.The typically high contents of carbon and silicon in cast irons as well as their soft graphite limit their treatability and load-bearing capacity for nitriding and hard coating. If an electron beam remelting process is carried out before these surface treatments, a hard ledeburitic surface layer free of graphite is produced, and serves as a supporting layer for the hard and typically thin compound layer or PA-CVD coating after combined treatments.Comparative wear tests (pin-on-disc) have shown that, especially for low loads, the wear rates of all single and duplex treatments are comparable, though considerably better than for the untreated base material. For higher loads, the superiority of Korrespondenzautor:

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Nitrieren und Nitrocarburieren∗

Cited by 19 publications

References 7 publications

Spectroscopic study of plasma nitrocarburizing processes with an industrial-scale carbon active screen

Spectroscopic study of plasma nitrocarburizing processes with an industrial-scale carbon active screen

Spectroscopic investigations of plasma nitrocarburizing processes using an active screen made of carbon in a model reactor

Potenziale von ausgewählten Randschichtbehandlungsverfahren sowie deren Kombinationen zur Verbesserung des Verschleiß- und Korrosionsverhaltens von Gusseisenwerkstoffen

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