Entwicklung von Prozessen zum Tiefnitrieren von Zahnrädern*

Hoja, S.; Hoffmann, Fabian; Zoch, H.‐W.; Schürer, Sina; Tobie, Thomas; Stahl, Karsten

doi:10.3139/105.110271

Cited by 6 publications

(13 citation statements)

References 6 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Investigations on deep nitriding were already carried out in the 1980s [6], when the nitriding plant technology was not yet sufficiently developed to enable controlled and reproducible nitriding treatments to be carried out in gas or plasma. For this reason, more recent investigations concern also nitriding processes for achieving high nitriding hardness depths [4,[7][8][9]. In [4] material-oriented two-stage processes for deep nitriding were developed with the aim of achieving high nitriding hardness depths with the highest possible strength.…”

Section: Of 12mentioning

confidence: 99%

“…For this reason, more recent investigations concern also nitriding processes for achieving high nitriding hardness depths [4,[7][8][9]. In [4] material-oriented two-stage processes for deep nitriding were developed with the aim of achieving high nitriding hardness depths with the highest possible strength. These processes were carried out according to the two-stage principle developed by Floe [10,11], where a closed compound layer was formed during the first stage.…”

Section: Of 12mentioning

confidence: 99%

“…Therefore case hardening is frequently used for larger gears, since higher case depths can be achieved in a shorter time. Nevertheless, nitriding offers some process-related advantages compared to case hardening, such as better protection against scuffing, wear and corrosion, higher surface hardness, a temperature-stable surface layer for use at higher temperatures, as well as less dimensional and shape changes and thus generally no need for reworking [4].…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Compound Layer Design for Deep Nitrided Gearings

Hoja

Steinbacher

Zoch

2020

Metals

View full text Add to dashboard Cite

Deep nitriding is used to obtain a nitriding hardness depth beyond 0.6 mm. The long nitriding processes, which are necessary to reach the high nitriding hardness depths, mostly have a negative influence on the hardness and strength of the nitrided layer as well as on the bulk material. The compound layer often is considered less, because in most practical cases, it is removed mechanically after nitriding, to avoid spalling in service. However, in former investigations, it was shown, that thick and compact compound layers have the potential for high flank load capacity of gears. The investigations focus on the simultaneous formation of a high nitriding depth and a thick and compact compound layer. Beside the preservation of the strength, a challenge is to control the porosity of the compound layer, which should be as low as possible. The investigations were carried out using the common nitriding and heat treatable mild steel 31CrMoV9, which is often used for gear applications. The article gives an insight on the development of multistage nitriding processes studied by short- and long-term experiments aiming for a specific compound layer build-up with low porosity and high strength of the nitride layer and core material.

show abstract

Section: Of 12mentioning

confidence: 99%

Section: Of 12mentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Compound Layer Design for Deep Nitrided Gearings

Hoja

Steinbacher

Zoch

2020

Metals

View full text Add to dashboard Cite

show abstract

“…The increased NHD values have been achieved by increasing the nitriding temperature and the nitriding time in a twostage nitriding process. Details of the heat treatment can be found in [19]. Due to the increased nitriding temperature and time, the negative effects such as edge bulges, increased gear roughness and reduced gear quality were slightly increased compared to a state-ofthe-art nitriding process.…”

Section: Flank Load Carrying Capacitymentioning

confidence: 99%

Increasing the load carrying capacity of highly loaded gears by nitriding

et al. 2019

View full text Add to dashboard Cite

Nitriding is a common heat treatment process for highly loaded gears. A very hard compound layer with a thickness of a few microns is produced at the surface of the gear. In the underlying material areas, a diffusion layer with nitride precipitations is formed. This publication summarizes the state of knowledge of nitrided gears and gives an overview of the current state of research in the field of nitrided gears. It can be concluded that a high load carrying capacity of nitrided gears is dependent on an adequate NHD and a stable compound layer. However, due to the increased surface roughness after nitriding, the risk of micropitting increases, too. Therefore, it may be favourable to grind the gears after nitriding. Ground gears also can provide a high load carrying capacity, but it must be taken into account that the wear performance will decrease significantly, since it is mainly influenced by the compound layer. In addition, nitrided gears usually show a high sensitivity against local load peaks. Beyond creating a stable compound the layer, the realization of a sufficient nitriding hardness depth with larger gear sizes is a focus in the current field of research.

show abstract

“…Finally, in order to keep high compressive residual stress during nitriding, one must, firstly, promote the precipitation of cementite by limiting the diffusion of carbon atoms released during the transformation of initial carbides (low temperature, high nitriding potential), and secondly, limit the transformation of cementite into iron nitrides and so the nitrogen supersaturation of the matrix in order to save the treated surface from the carbon diffusion and decrease of the volume fraction of precipitates. The last can be performed during the process by decreasing the nitriding potential in a multi--steps nitriding [33].…”

Section: Carbides Transformationsmentioning

confidence: 99%