High-Pressure Gas Nitriding of Steels

Герасимов, С. А.; Golikov, V. A.; Gress, M. A.; Mukhin, G. G.; Snop, V. I.

doi:10.1023/b:msat.0000043107.19600.2c

Cited by 5 publications

(3 citation statements)

References 1 publication

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“…Additionally, conventional controlled gas nitriding process have also been realized in order to compare the structure of the Fe Armco surface layer and determine the advisability of applying a short time to this type of nitriding process (4 hours -1 I stage + 3 II stage). It is known that the time of conventional controlled gas nitriding in industrial conditions ranges from few to several hours, and the generated diffusion layers are between few microns to even a few milimetres [14]. Furthermore authors based on their earlier research have determined that the use of plasma nitriding is favorable up to about 12 hours and considering active screen method, the applications of times of about 10 h for austenitic materials, and up to about 8 hours for ferritic materials is mentioned [15][16][17][18].…”

Section: Resultsmentioning

confidence: 99%

Archives of Metallurgy and Materials

Jasiński¹,

Sitarz²,

Frączek³

et al. 2018

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The paper presents a comparison of the nitrided layer structure and morphology formed with a conventional controlled gas method, widely use in industrial applications and a layer formed with cathode plasma nitriding (CPN) and active screen plasma nitriding (ASPN). Nitriding processes were realized at 793K for different times and altering parameters, depending on the nitriding process technique. Research have been realized on the Fe Armco material using light microscopy (LM), scanning electron microscopy (SEM, SEM/EBSD), X-ray diffraction (XRD-GID) and atomic force microscopy (AFM). Analysis of the results has confirmed that the structure of the nitrided layer depends mainly on process methodology. In addition Authors has also analyzed kinetics of the process which varies and depends mainly from the surface layer saturation mechanism and nitriding parameters. Acquired knowledge on the structural components of the nitrided layer made it possible to optimize the nitriding parameters in order to reduce or even eliminate the usually unfavorable, brittle compounds and porous zones and of the nitrided layer in the aspect of exploitation properties improvement of the metallic materials.

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Section: Resultsmentioning

confidence: 99%

Archives of Metallurgy and Materials

Jasiński¹,

Sitarz²,

Frączek³

et al. 2018

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“…The nitriding process conditions (temperature, chemical composition of the nitriding medium, ammonia dissociation degree, nitriding time), have been chosen so that the proportion of fragile phases in the nitrided layer is as low as possible (ideally zero). If they occur, however, measures can be taken to reduce them later, or from the start the atmosphere can be diluted with gases to ensure a change in nitrogen potential, as they showed Kogan, 1976, 1982;Minkevici, 1965;Lahtin et al, 1991;Slycke et al, 2015;Gerasimov et al, 2020;Winter, 2009;Iurghenson, 1962;Kutschmann et al, 2019;Zâsik et al, 1980;Korecka et al, 2018;Gerasimov et al, 2004;Edenhofer et al, 2008). The performances obtained by nitriding are limited and depend very much on the chemical composition of the steel, so on the type, and proportion of nitrides generated by thermochemical processing.…”

Section: Introductionmentioning

confidence: 99%

Nitriding in ammonia-nitrogen gaseous mixtures, after the simultaneous saturation with Ti and Al

Cotruț¹,

Ghinea²,

Brânzei³

et al. 2022

IJSURFSE

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The paper addresses aspects of nitriding in ammonia-nitrogen gaseous mixtures, after simultaneous saturation with Ti and Al using solid powdery media. The effects quantification of the nitriding conditions variation, i.e., temperature, the ammonia dissociation degree and dilution degree with nitrogen, on the layer's growth kinetics, simultaneous saturated with Ti and Al and subsequently nitrided, in the case of two metallic materials, Fe-ARMCO and 34CrAlMo5 steel, could be ensured using the second-order non-compositional experimental programming method. It was concluded that, in the case of ammonia dilution with nitrogen, the variation of the ammonia dissociation degree in the range 20÷70%, in the context of simultaneous dilution of ammonia with nitrogen, statistically significantly influences the layers growth kinetics with increasing nitriding temperature. On the other hand, for a dilution degree of ammonia with about 30% nitrogen and an ammonia dissociation degree of about 45%, the most intense layers growth kinetics was highlighted if the nitrided layer has been previously saturated simultaneously with Ti and Al.

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“…The working tool works under the conditions of high temperatures, intensive sliding speeds, and considerable specific pressure that causes the necessity of using highalloyed heat-resistant instrument steel as material so that it has increased viscosity and durability [2].…”

Section: Introductionmentioning

confidence: 99%

Carbonitration of a Tool for Pressing Stainless Steel Pipes

Иванов

Mohylenets²,

Dumenko³

et al. 2020

JES

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To upgrade the operational stability of the tool at LLC “Karbaz”, Sumy, Ukraine, carbonation of tools and samples for research in melts of salts of cyanates and carbonates of alkali metals at 570–580 °C was carried out to obtain a layer thickness of 0.15–0.25 mm and a hardness of 1000–1150 НV. Tests of the tool in real operating conditions were carried out at the press station at LLC “VO Oscar”, Dnipro, Ukraine. The purpose of the test is to evaluate the feasibility of carbonitriding of thermo-strengthened matrix rings and needle-mandrels to improve their stability, hardness, heat resistance, and endurance. If the stability of matrix rings after conventional heat setting varies around 4–6 presses, the rings additionally subjected to chemical-thermal treatment (carbonitration) demonstrated the stability of 7–9 presses due to higher hardness, heat resistance, the formation of a special structure on the surface due to carbonitration in salt melts cyanates and carbonates. Nitrogen and carbon present in the carbonitrided layer slowed down the processes of transformation of solid solutions and coagulation of carbonitride phases. The high hardness of the carbonitrified layer is maintained up to temperatures above 650 °C. If the stability of the needle-mandrels after conventional heat treatment varies between 50–80 presses, the needles, additionally subjected to chemical-thermal treatment (carbonitration) showed the stability of 100–130 presses due to higher hardness, wear resistance, heat resistance, the formation of a special surface structure due to carbonitration in melts of salts of cyanates and carbonates. Keywords: needle-mandrel, matrix ring, pressing, heat treatment, carbonitration.

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High-Pressure Gas Nitriding of Steels

Cited by 5 publications

References 1 publication

Archives of Metallurgy and Materials

Archives of Metallurgy and Materials

Nitriding in ammonia-nitrogen gaseous mixtures, after the simultaneous saturation with Ti and Al

Carbonitration of a Tool for Pressing Stainless Steel Pipes

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