Nitriding Treatment Research Articles

Gaseous nitriding of Co-10 at% and -15 at% Cr alloys at 400 °C and 450 °C

Co-10 at% and -15 at% Cr with the stable hexagonal close packed (hcp) crystal structure at room temperature have been subjected to gaseous nitriding treatment using nitriding temperatures of 400 °C and 450 °C far below the austenite start temperature. Using X-ray and electron backscatter diffraction (EBSD), structural changes as a result of nitrogen incorporation into the initial hcp lattice can be divided into the following steps: (i) expansion of the lattice due to N uptake yielding hcp (hcpexp) at nitriding temperature of 400 °C, (ii) gradual transformation of hcpexp into an expanded face-centered cubic phase (fccexp) by increasing time at 400 °C/ or temperature to 450 °C (mixture of two phases), (iii) development of stable nitrided layer containing fccexp using moderate nitriding times up to 3 h at 450 °C and (iv) decomposition of fccexp layer into CrN nitrides and less expanded austenite and the reverse transformation from fcc to hcp at near-surface regions at 450 °C after prolonged nitriding time of 24 h. Due to occurrence of step (iv), the square-root treatment-time dependence of the nitrided layer thickness breaks down. Nitrogen-depth profiles obtained for Co-15 at% Cr by glow-discharge optical emission spectroscopy (GDOES) along with the Non-Rutherford MeV proton backscattering spectrometry reveal a nitrogen supersaturation of around 20 at% at surface-adjacent areas in hcpexp. A relatively large unit volume expansion has been recognized for hcpexp with a change of c/a ratio of around 0.6%. Hardness-depth profiles obtained for nitrided Co-10 at% and -15 at% Cr alloys using nanoindentation evidence an increase in hardness inside the nitrided layer, compared to the untreated core.

Effects of surface topography at different scales on the dispersion of the wetting data for sessile water droplets on nitrided austenitic stainless steels

Plasma nitriding is used to increase the durability of steels. The wettability of nitrided surfaces is poorly studied. The ability of nitriding in modifying the wetting and evaporation of sessile droplets on austenitic stainless steel is studied. Transferred plasma for nitriding provides independent substrate biasing giving the opportunity to tailor the surface before and during the nitriding treatments. It was shown that a cleaning treatment (ArH2 plasma) produces topographical modifications of the surface by selective sputtering of the grains giving contact angles between 80 and 90°. Similar results are obtained when the nitriding treatments are carried out with a rather high bias voltage. It is explained using the skewness (Ssk) topographical roughness parameter which reveals the asymmetry of the profile. The more the Ssk is, the higher the contact angle is. During nitriding treatments, the very high internal stresses leads to the formation of spikes at the grain boundaries. Pinning of the three-phase contact line on peaks localized at grain boundaries are responsible for high contact angles. For nitriding treatments carried out with lower bias, surface contamination occurs and a discontinuous oxynitride layer is formed. The nanostructure formed by these oxides gives contact angles up to 120°.

Nitriding behavior and mechanical properties of AerMet100 steel and first-principles calculations of phase interfaces

In this paper, quenched AerMet100 steel specimens are plasma nitrided at different temperatures (from 440 °C to 500 °C), and their microstructures and mechanical properties are investigated. Surface layer hardness variation induced by plasma nitriding is also analyzed and correlated with microstructural characteristics and concentration distributions of carbon and nitrogen. Results show that wear resistance of AerMet100 steel after nitriding treatment exhibits various degrees of improvement compared with the un-treated specimen. Especially for the nitrided specimens from 460 °C to 500 °C, volume wear rate is reduced by more than 88%. Such great improvement is mainly attributed to the absence of brittle ε-Fe2-3N phase and the presence of a thick gradient nitrided layer. The interfacial properties of γ′-Fe4N(111)/α′N(011) are investigated by first-principles calculations. Six interface models with different γ′-Fe4N(111) termination and stacking sites are investigated to clarify their effects on the interfacial adhesion. The Fe-terminated Bridge site model exhibits a stronger adhesion tendency after relaxation, which can be regarded as the strongest interface. We found that the alloying additives benefit the γ′-(Fe,M)4N(111)Fe/α′N(011) interfacial adhesion in the order Si < Zr < Cu < Al < Ni < Mn < Co < Nb < Ti < V < Mo < Fe < Cr. Wherein, only Cr can be regarded as enhancers, and doping with Cr and Si are the most prominent representatives of strengthening and weakening effects, respectively. In addition, the bonding characteristics of two representative interface structures doped with Cr and Si are further studied. Density of states (DOS) and crystal orbital Hamilton population (COHP) analysis indicate that the significantly improved interfacial adhesion of Cr-doped is mainly due to the significant improvement of the enhanced Fe-Fe bonding. These results may provide some important inspirations for future experimental work of preparing high-performance nitrided layer.

Improvement on pitting wear resistance of gears by controlled forging and plasma nitriding

In the present investigation, the use of a bainitic steel for forged gears applications and the suitability of different plasma nitriding treatments is discussed. The gears were forged, machined, ground, polished, and nitrided at 500 °C with three sets of N2–H2 gas mixtures, containing 5, 24, and 76 vol.% N2, to develop a nitrided case of approximately 300 μm depth. Gears were characterized before and after the nitriding concerning the phase composition, microstructure, microhardness, fracture toughness, and residual stresses states. Pitting wear tests were performed on a standard Forschungsstelle für Zahnräder und Getriebebau (FZG) test rig. The nitrided gears with 24 and 76 vol.% N2 formed a biphasic compound layer of ε-Fe2-3(C)N and γ′-Fe4N. As the volume fraction of nitrogen in the gas mixture was decreased, the detected content of γ′-Fe4N in the compound layer increased, but a monophasic compound layer was only reached with 5 vol.% N2. The nitrogen rich gas composition increased the surface hardness and decreased the fracture toughness of the compound layer, as they have more ε-Fe2-3(C)N. The diffusion zone of the different nitrided surfaces showed residual compressive stresses. The best performance was obtained in the nitrided gears with 24 vol.% N2, due to the better combination between the surface hardness, fracture toughness, residual stresses, and compound layer thickness. The nitrided gears with 24 vol.% N2 have ten times improvement over the non-nitrided gears, while the nitrided gears with 5 and 76 vol.% N2 have an improvement of three point seven and five point four times.

Duplex treatment of arc plasma nitriding and PVD TiN coating applied to dental implant screws

In modern dentistry, surface modification technology is critical for the long-term service of dental implants. The purpose of this study was to evaluate the effects of the duplex treatment of arc plasma nitriding and TiN coating on the mechanical behavior of implant systems. The Ti6Al4V screws of dental implants were treated by physical vapor deposition (PVD), arc plasma nitriding (APN), and arc plasma nitriding-physical vapor deposition (APN-PVD). The surface characteristics, loosening properties, and fatigue performance of different treated screws were analyzed. The results showed that APN-PVD duplex treatment produced a gradient surface structure, reduced the surface roughness, and improved the TiN coating adhesion. Compared with the PVD-treated screws alone, APN-PVD-treated screws improved anti-loosening performance, reduced surface wear, and prolonged fatigue life. Duplex treatment by arc plasma nitriding and TiN coating may be a method suitable for dental applications.

Wear and corrosion studies of duplex surface-treated AISI-304 steel by a combination of cathodic cage plasma nitriding and PVD-TiN coating

This work aims to improve the surface properties of AISI-304 austenite stainless steel by using duplex treatment of cathodic cage plasma nitriding (CCPN) and PVD-TiN, and the results are compared with individual treated samples. This combination of treatments is used to improve the inherent drawbacks of individual PVD deposited TiN, such as voids, cracks, and detachment of hard layer from steel due to significant differences in the hardness of steel and hard layer. The hardness of steel (1.9 GPa) is improved to 17 GPa, 12 GPa, and 22 GPa by using only TiN, CCPN, and duplex treatment. The only TiN deposited sample shows the formation of layer with intense diffraction peaks along (311) and (400) orientation, and its orientation changed with intense peaks along (111), (200), and (220) by using duplex treatment, which increases the hardness. Furthermore, the wear resistance is improved by all treatments, specifically by using duplex treatment. While using a ball-on-disc wear tester, the TiN layer is not detached from the substrate in the duplex treated sample, in contrast with the only TiN sample. Furthermore, the corrosion rates are reduced by using the duplex treatment and the appliance of plasma nitriding before the TiN fills the voids and cracks in layer, and thus, the duplex layer effectively prevents steel against corrosive environment. This study suggests that combining these treatments improves surface hardness, wear resistance, and corrosion resistance.

A microabrasion wear study of nitrided α-Ti and β-TiNb PVD metallic thin films, pre-deposited onto titanium alloy substrates

In this paper, we study the structure, mechanical properties and abrasion resistance of two triode-plasma nitrided (TPN) titanium alloys, pre-coated with metallic α-Ti or β-TiNb layers deposited by physical vapour deposition (PVD). The chosen alloys were Ti-6Al-4V and Ti-4Al-10V-22Mo, which are predominantly alpha- and beta-phased, respectively – each presenting different challenges, in terms of their nitriding response. Although duplex nitriding + PVD coating is now quite widely employed on steels (and increasingly on titanium alloys) to improve load-bearing capacity and wear resistance, the use of PVD coatings prior to diffusion treatment to control surface roughness – and, in the case of Ti-alloys particularly, to optimise their ‘challenging’ diffusion kinetics has received little or no attention so far. The TPN process enables diffusion treatments to be carried out at 700 °C – which is lower than the beta-transus temperature of Ti (and of most Ti alloys). Optical microscopy, scanning electron microscopy, atomic force microscopy, X-ray diffraction, nanoindentation, and surface profilometry were used to characterize the nitrided and coated/nitrided samples. It was found that the nitrogen concentration and surface hardness for all samples was significantly increased, and that the surface roughness values significantly increased for uncoated Ti alloy substrates after TPN treatment – due to intense, grain orientation-dependent plasma etching effects. However, our novel approach of PVD pre-deposition of a nanostructured metallic coating prior to nitriding reduces surface roughening effects quite dramatically. The micro-abrasion resistance of Ti- and TiNb-coated Ti-6Al-4V substrates was significantly enhanced after nitriding treatment; on the other hand, similar improvements were not found for the metastable-beta Ti-4Al-10V-22Mo substrates – due to the different nitriding behaviour of the pre-deposited PVD surface layers. The “sputter removal” rates for the metallic coatings were high, but all coatings survived in part until the end of the nitriding process.

Fatigue properties of plasma nitriding for dental implant application

Statement of problemFatigue failure of implant components is a common clinical problem. Plasma nitriding, an in situ surface-strengthening method, may improve fatigue properties of dental implants. PurposeThe purpose of this in vitro study was to evaluate the effect of plasma nitriding on the fatigue behavior of implant systems. Material and methodsThe preload and friction coefficient of plasma nitrided abutment screws, as well as settlement of the implant-abutment interface, were measured. Then, the reverse torque values and pullout force were evaluated after cyclic loading. Finally, the fatigue properties of the implant system were investigated with static fracture and dynamic fatigue life tests, and the morphology of the fracture on the surface of the implant system was observed. ResultsThe plasma nitriding treatment reduced the friction coefficient; increased the preload, settlement value, reverse torque values, pullout force, and static fracture load; and prolonged fatigue life. Furthermore, abutment screws with plasma nitriding treatment showed a different fatigue fracture mode. ConclusionsPlasma nitriding improved mechanical performance and may be a suitable way to optimize the fatigue behavior of dental implants.

INVESTIGATION OF THE EFFECT OF NITROCARBURIZING TREATMENT ON TRIBOLOGICAL PROPERTIES OF AISI 1045 MEDIUM CARBON STEEL

In this paper, the effect of nitrocarburizing treatment on tribological properties of AISI 1045 steel was investigated. This medium carbon steel was used in automotive industry, especially in the manufacture of machine components due to the good mechanical properties and lower cost. Characterization of the surface layer of treated samples was made by optical microscopy (OM), Vickers microhardness test, scanning electron microscope (SEM), and pin-on-disk wear machine. Experimental results showed that the surface layers formed through nitrocarburizing processing at 580 °C (compound layer and diffusion zone) increased the microhardness. It was found also that the nitriding treatment reduced the friction coefficient and improved the wear resistance, where the specific wear rate were decreased to 1/9 was noticed after 10 hours of nitriding time.

Comprehensive analysis of nitriding behavior and synergistic strengthening mechanism on quenched M50 steel

M50 secondary hardening steel is widely used as high-end bearing steel for engine shafts in the aerospace industry. In this study, plasma nitriding at different temperatures varying from 410 to 570 °C was performed on quenched M50 steel to investigate the response of the microstructure and mechanical properties to nitriding temperature and advance the scientific understanding of the mechanism involved. The nitrided samples were fully characterized by scanning electron microscopy, transmission electron microscopy, X-ray diffraction, electron microprobe analysis, Vickers hardness tester, and Pin-on-disc tribometer. The results revealed that the nitrided layer's thickness, microstructure, hardness, and wear resistance depended on the treatment temperature. When the nitriding treatment performs at secondary-hardening temperature, the samples were endowed with excellent wear resistance and gentle hardness profile, i.e., hardness profile with a gradually reducing hardness profile towards the core, attributed to the synergistic strengthening. Moreover, the thermodynamic calculation was involved to clarify the formation mechanism of coarse intergranular precipitation, which can be connected to form a wave shape line at higher temperatures.

Hierarchically nanostructured Ni2Fe2N as an efficient electrocatalyst for hydrazine oxidation reaction

A Ni foam-supported, hierarchically nanostructured Ni 2 Fe 2 N nanoflowers (Ni 2 Fe 2 N/NF) exhibits high activity and good operation stability towards hydrazine electrooxidation. • Hierarchically nanostructured Ni 2 Fe 2 N was anchored on Ni foam by a two-step procedure. • Ni 2 Fe 2 N/NF exhibits higher HzOR activity than the top-notch electrocatalysts hitherto reported. • Ni 2 Fe 2 N/NF shows high reaction selectivity toward faradic decomposition of hydrazine. The application of direct hydrazine fuel cells (DHFCs) as portable or vehicular power sources calls for the development of cheap and efficient catalysts for the anodic hydrazine oxidation reaction (HzOR). Herein, we report the facile fabrication of a Ni-foam-supported, hierarchically nanostructured Ni 2 Fe 2 N (Ni 2 Fe 2 N/NF) as a high-performance HzOR catalyst. The Ni 2 Fe 2 N/NF catalyst was fabricated by a simple hydrothermal method and a subsequent nitridation treatment. The thus-prepared Ni 2 Fe 2 N possesses high intrinsic activity towards HzOR, good electronic conductivity as well as a hierarchical architecture, which endows the catalyst with abundant active sites and improved mass transfer properties. Benefiting from these attributes, Ni 2 Fe 2 N/NF demonstrates highly efficient HzOR performance with a high current density of 1017 mA cm −2 at 0.3 V versus RHE, excellent stability and a nearly 100% selectivity for the faradaic hydrazine decomposition following 4-electron pathway, surpassing most previously reported top-notch HzOR electrocatalysts.

Physical and Mechanical Characterization Study of Thin Nitriding Layers Produced by Plasma on Low Alloy Steel

The present study has been conducted in order to obtain iron nitrides layer on AISI4140 steel by using plasma nitriding treatment. As one of several parameters of this process, the nitrogen rate ranging from 10 to 70% with a step of 20% was chosen. The structure, the morphology, the thickness and the hardness of iron nitrides layer were investigated. As a result, the improvement of surface hardness of nitrided steel was identified related with the increase of compound layer thickness due to the increase of activation rate. The steel substrate treated at high activation rate presents hardness 3 times higher than that of untreated steel.

Nitriding behaviour of the intermetallic alloy FeAl

Abstract An iron-based intermetallic FeAl alloy was gas nitrided under well-defined conditions, and the influences of the process parameters, i. e., time, temperature, and nitriding potential on the layer formation, were investigated. Microstructural, morphological, and chemical characterization of the nitride layer was performed by means of glow discharge optical spectroscopy, electron probe microanalysis, scanning electron microscopy, X-ray diffraction, internal-stress measurement, hardness– depth profiles, and indentation fracture mechanics. Pin-on-disk tests were carried out to investigate the load-bearing capacity and wear resistance of the nitride layers. The formation of hexagonal AlN during the nitriding treatment leads to an increase in hardness of about 920 – 980 HV 0.025 and to a significant improvement of the wear resistance. Additional annealing tests proved the thermal stability of the nitride layer up to 950 °C.

Achieving Stable Zinc-Ion Storage Performance of Manganese Oxides by Synergistic Engineering of the Interlayer Structure and Interface.

Manganese oxide is a promising cathode material for rechargeable aqueous zinc-ion batteries (ZIBs). However, the low electronic conductivity and unstable structure evolution of manganese materials often result in poor rate performance and rapid capacity decay. Herein, we design N-doped Na2Mn3O7 (N-NMO) by combining sodium preintercalation and nitridation treatment strategies to stabilize the crystalline structure and reaction interface. Sodium preintercalation not only enlarges the interlayer distance for fast Zn2+ ion diffusion but also serves as a robust pillar to stabilize the crystalline structure during cycling. Meanwhile, the nitridation layer on the surface of Na2Mn3O7 particles is favorable for enhancing the electronic conductivity and inhibiting the cathode dissolution issue during repeated cycling. Consequently, the as-prepared N-NMO exhibits high reversible capacity (300 mAh g-1 at 0.2 A g-1), good rate capability (100 mAh g-1 at 10 A g-1), and outstanding long-term cycling stability (high capacity retention of 78.9% after 550 cycles at 2 A g-1). Considering the facile and simple synthesizing methods, the synergistic engineering of the interlayer structure and interface is expected to provide new opportunities for the development of high-performance Mn-based cathode materials for aqueous ZIBs.

Effect of plasma nitriding on tribological properties of nickel‑boron-nanodiamond electroless coatings

This study is an effort to investigate the synergic effect of nano-diamond (ND) addition and plasma nitriding (PN) treatment on tribological and structural properties of nickel‑boron (NiB) coatings. NiB/ND nanocomposites containing different amounts of NDs (0.0, 0.1, 0.5, and 1.0 g/L) were produced in an electroless bath. Then, plasma nitriding was conducted on the samples for 1 h at 400 °C in an N2-H2 environment. To study phase analysis and examine the surface morphology of the samples, X-ray diffraction (XRD) and field emission scanning electron microscopy (FE-SEM) were utilized. The wear behavior and friction were determined under the normal load of 10 N using the pin-on-disk method. The surface roughness, microstructure, and microhardness were also assessed. The results showed that, as the ND concentration increased, the amorphous structure of as-plated (AP) Ni-B transformed to a semi-crystalline one. Moreover, the amorphous structure of the as-deposited NiB/ND coatings changed to a crystalline one after plasma nitriding, which resulted in a higher hardness value. NiB/0.5ND coating showed the highest hardness value (1523 HV0.1) and the highest wear resistance (0.8×10−10 Kg/N.m). The smoothest wear trace with no visible cracks is related to the worn surface of PN NiB/0.5ND sample, suggesting that the NiB/ND nanocomposite can be a promising candidate for surface engineering processes.

Enhancement of optical property and crystal structure for GaN films on 2D MoS2 buffer layer by nitridation treatment

The growth of GaN films on layered 2D-MoS2/c-sapphire substrate by plasma-assisted molecular beam epitaxy system was investigated. Pre-nitridation process and deposition time as growth parameters were employed to exploit the heteroepitaxial growth of GaN films at the temperature of 700 °C. The characterizations of surface condition, surface morphology, chemical composition, optical properties, crystal orientation and quality of GaN epitaxial layers were conducted by reflection high energy electron diffraction (RHEED), scanning electron microscope (SEM), atomic force microscope (AFM), X-ray photoelectron Spectroscopy (XPS), Raman spectroscopy, photoluminescence spectroscopy (PL) and high-resolution X-ray diffraction (HR-XRD), respectively. The pre-nitridation process and growth duration can enhance the optical properties and crystal quality of GaN films on 2D-MoS2/c-plane sapphire. The pre-treatment of MoS2 layer by nitrogen plasma before the growth, providing a wetting layer of nitrogen for GaN growth, can eliminate the oxygen contamination and reduce the defects in the films. Band-to-band emission of Wurtzite GaN with the bandgap of 3.5 eV can be improved by pre-nitridation process, and yellow band emission can be suppressed due to the elimination of defect states in the films. Meanwhile, the crystal orientation and quality can be improved by the pre-nitridation process and longer duration of growth time. This study demonstrates a van der Waals epitaxial GaN films on 2D-MoS2 layer with higher crystal quality by pre-nitridation process, and it provides a potential solution for the future applications of GaN-based devices.

Three-dimensional Ni-MoN nanorod array as active and non-precious metal electrocatalyst for methanol oxidation reaction

• Three-dimensional Ni-MoN nanorod array electrocatalyst is facilely designed and synthesized. • The nitridation process ensures the uniform distribution of active Ni sites across the robust MoN nanorods. • The constructed Ni-MoN nanorod array exhibits a promising electrocatalytic activity towards methanol oxidation reaction. The development of direct methanol fuel cells requires low-cost, non-noble-metal electrocatalysts. However, it has not been widely used because of its limited activity, poor durability, and slow kinetics. Herein, the 3D nanostructured arrays of Ni-MoN composite nanorods were facilely prepared on the nickel foam (Ni-MoN NR/NF), which involves the direct hydrothermal synthesis of NiMoO 4 on NF and further nitridation treatment in the atmosphere of ammonia. The nitridation ensures the uniform distribution of active Ni sites across the robust MoN nanorods. Owing to the collaborative effect of Ni and the specific 3D MoN nanorod structure, the Ni-MoN NR/NF exhibits a promising electrocatalytic activity towards methanol oxidation reaction (MOR), which shows excellent activity (374 mA cm −2 @0.8 V vs. Hg/HgO), fast kinetics (40 mV dec −1 for the Tafel slope) and good stability. This work has shed light on the design of high-performance non-noble-metal electrocatalysts for MOR.

Effect of electric potentials on high‐temperature plasma nitriding of 2Cr13 stainless steel with active screen assisted

AbstractThe influence of electric potentials on the characteristics of modified layers with plasma nitriding of 2Cr13 stainless steel at a high temperature was investigated. Three active screens were placed on the cathodic plate. Three groups of 2Cr13 stainless steel samples were set with cathodic, anodic, and floating potentials. Samples were nitrided at 500 °C for 5 h in an ammonia atmosphere. The treated samples were analyzed using x‐ray diffraction, scanning electron microscopy with energy dispersive x‐ray spectroscopy, surface roughness tester, and atomic force microscopy. It is proved that nitriding treatments can be suitably carried out at three electric potentials, but the corresponding modified layers take on different microstructure, morphology, and hardness behaviors. It found that the three nitrided samples are mainly composed of the ϵ−Fe2‐3N and γ’−Fe4N phases. The order of thicknesses of the nitrided layers is: floating &lt; anodic &lt; cathodic potential. The results also demonstrated that electric potentials play essential roles in the corrosion resistance and tribological properties in plasma nitriding treatment. Because there is no visible precipitation of chromium nitride in the modified layer, the corrosion resistance of the floating nitrided sample is better than that of the other two samples.

Gaseous nitriding of additively manufactured maraging steel; nitriding kinetics and microstructure evolution

The nitriding response of additively manufactured M300 maraging tool steel was investigated through a series of nitriding treatments at different temperatures in the range 360–480 °C for a duration of 40 h. The interaction between nitrogen and alloying element nitrides (Ti and Mo) and intermetallics (Ni 3 Ti and Ni 3 Mo) was studied by comparing nitriding responses of as-solution treated and subsequently aged specimens. The nitriding behavior was found to depend strongly on the initial condition of the material and the nitriding temperature applied. Ultra-low temperature nitriding at 360 °C was found to be feasible as it resulted in a nitrided case, albeit with incomplete precipitation hardening of the bulk structure, thus resulting in a softer core. The application of a post-ageing treatment resulted in full bulk hardening and distinctly changed the appearance of the hardness profile. • Nitriding of solution treated and not aged maraging steel creates deeper case. • Nitride and intermetallic formation competes at increased nitriding temperatures. • Ultra-low temperature nitriding of maraging steel is feasible. • Post-ageing of ultra-low temperature nitriding creates promising hardness profile.

Optimisation of Thermal Processes with Plasma Nitriding on Vanadis 4 High Speed Steel.

Vanadis 4 steel is a tool steel processed by powder metallurgy (PM). Its main alloying elements are Cr, V and Mo. Through the application of a design of experiments with six factors and eight experiments, the parameters of the process related to the thermal treatment of these steels are deliberately varied. Those thermal parameters related to the destabilisation of austenite were analysed: the cooling method in quenching, tempering and the application of an ionic nitriding treatment. Through XRD, the percentage and types of precipitated crystalline phases were determined, and, through SEM-EDX, the microstructure was revealed. At the same time, through a pin-on-disc test, those factors with a significant influence on resistance to wear were determined. It has been concluded that, in order to increase resistance to wear, treatments of destabilisation of the austenite at 900 °C with oil quenching, tempering at 550 °C for 4 h and a subsequent treatment of plasma nitriding would be very favourable. This tempering favours a second destabilisation of the austenite and its transformation into martensite, as well as the joint precipitation of type M7C3 and MC carbides. The thickness of the nitrided layer exceeds 100 microns and generates a fully adhesive wear mechanism.