Low-Temperature Carburization of AL-6XN Enabled by Provisional Passivation

Li, Zhen; Illing, Cyprian; Heuer, A. H.; Ernst, F.

doi:10.3390/met8120997

Cited by 9 publications

(2 citation statements)

References 38 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…A new surface activation method for low-temperature cementation was presented in Li et al [16] for AISI-AL-6XN steel. The method involves the removal of passivating surface oxide and a potentially existing highly plastically deformed surface layer and immersion in ethanol and subsequent drying in nitrogen.…”

Section: Introductionmentioning

confidence: 99%

Deep Contact Strength of Surface Hardened Gears

Beskopylny

Meskhi

Onishkov

et al. 2020

Metals

View full text Add to dashboard Cite

This article is devoted to the analysis methods for assessing the load capacity of gears hardened by surface chemical-thermal treatment (CTT), which are characterized by structural and chemical heterogeneity. The leading type of failure is determined by several factors, the main of which are the surface and deep layer properties of the material, which fundamentally differ in the energy and structural state. Intercrystalline fracture mechanisms predominate in the surface layers and transcrystalline in the core. For these cases, the classical failure criteria of Mohr, Tresca, and Mises lead to significant errors. Therefore, the bearing capacity of the layer component is investigated by the generalized criterion of the limit state of the Pisarenko-Lebedev structurally inhomogeneous material, considering changes in its plastic properties due to surface hardening. The reliability of predicting the level of bearing capacity of surface hardened steel parts, such as gears, was significantly improved. The influence of the plasticity parameter on the level of bearing capacity for various types of CTT is estimated. Calculations using the presented model show that for alloy steels with a Ni content up to 1%, the safety coefficient can be limited to 1.2, which will increase the bearing capacity by 25–27%.

show abstract

Section: Introductionmentioning

confidence: 99%

Deep Contact Strength of Surface Hardened Gears

Beskopylny

Meskhi

Onishkov

et al. 2020

Metals

View full text Add to dashboard Cite

show abstract

“…The process of increasing surface transparency by removing such obstacles is known as "surface activation." This can occur in various ways, e.g., by chemicalor plasma etching, and it can occur just at the beginning or continuously throughout the entire infusion process [7][8][9][12][13][14].…”

mentioning

confidence: 99%

Rapid Alloy Surface Engineering through Closed-Vessel Reagent Pyrolysis

Illing

Ren

Agaponova

et al. 2021

Metals

Self Cite

View full text Add to dashboard Cite

For rapid surface engineering of Cr-containing alloys by low-temperature nitrocarburization, we introduce a process based on pyrolysis of solid reagents, e.g., urea, performed in an evacuated closed vessel. Upon heating to temperatures high enough for rapid diffusion of interstitial solute, but low enough to avoid second-phase precipitation, the reagent is pyrolyzed to a gas atmosphere containing molecules that (i) activate the alloy surface by stripping away the passivating Cr2O3-rich surface film (diffusion barrier) and (ii) rapidly infuse carbon and nitrogen into the alloy. We demonstrate quantitatively that this method can generate a subsurface zone with concentrated carbon and nitrogen comparable to what can be accomplished by established (e.g., gas-phase- or plasma-based) methods, but with significantly reduced processing time. As another important difference to established gas-phase processing, the interaction of gas molecules with the alloy surface can have auto-catalytic effects by altering the gas composition in a way that accelerates solute infusion by providing a high activity of HNCO. The new method lends itself to rapid experimentation with a minimum of laboratory equipment.

show abstract