Characterization of plasma-nitrided iron by XRD, SEM and XPS

Gontijo, Leonardo Cabral; Machado, R.; Miola, E.J.; Casteletti, Luíz Carlos; Nascente, P. A. P.

doi:10.1016/j.surfcoat.2003.06.026

Cited by 84 publications

(44 citation statements)

References 21 publications

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“…The interaction of nitrogen and steel surface leads to the formation of different types of metallic nitrides, which form the socalled ''nitride layer". Starting from the solid surface, such a modified layer usually comprises an oxide layer, a compound zone and a diffusion zone [3,4]. The resulting structure of these zones depends on several processing parameters such as the concentration of alloying elements, exposure time, substrate temperature and gaseous mixture [5,6].…”

Section: Introductionmentioning

confidence: 99%

TRIBOLOGICAL BEHAVIOR OF 42CrMo4 STEEL NITRIDED BY PLASMA

Saied¹,

Chala²,

Belahssen³

et al. 2015

Acta Metall Slovaca

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This paper presents wear behavior of the plasma nitrided 42CrMo4 steel. This steel is used in mechanical industry; it has been assessed by evaluating tribological properties and surface hardness by using a pin-on-disk wear machine and microhardness tester. Experimental results showed that the nitrides ε-Fe 2-3 N and γ'-Fe 4 N present in the compound layer increase the microhardness. It is found that plasma nitriding improves the wear rate and the presence of a hard and brittle compound layer on the surface causes an increase in wear of the specimen surface.

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Section: Introductionmentioning

confidence: 99%

TRIBOLOGICAL BEHAVIOR OF 42CrMo4 STEEL NITRIDED BY PLASMA

Saied¹,

Chala²,

Belahssen³

et al. 2015

Acta Metall Slovaca

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“…The treated sample was modelled by the equivalent circuit shown in figure 4 which is composed by elements: R e (the solution ohmic resistance), Q 1 and Q 2 elements, which represent a CPE 1 and CPE 2 respectively, R 1 resistance of the porous nitride layer, R 2 the charge transfer resistance at the metal/nitide interface. The polarization resistance is R P = R 1 + R 2 The values of equivalent circuit elements resulting from simulation by the EC-Lab 10.02 software are shown in table 1 for untreated sample and in table 2 for nitrided one.…”

Section: Methodsmentioning

confidence: 99%

“…The interaction of nitrogen and steel constituents leads to the formation of different types of metallic nitrides, which form the so-called ''nitride layer". Starting from the solid surface, such a modified layer usually comprises an oxide layer, a compound zone, and a diffusion zone 2 . The resulting structure of these domains depends on several processing parameters such as the concentration of alloying elements, exposure The presence of a nitride layer obviously changes the mechanisms of interaction between metallic materials and their surroundings, thus affecting their stability in aggressive environments 4 .…”

Section: Introductionmentioning

confidence: 99%

Corrosion behaviour of the 42CrMo4 Steel Nitrided by Plasma

Belahssen¹,

Chala²,

Benramache³

2013

Orient. J. Chem

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This paper presents corrosion behaviour of alloy 42CrMo4 steel nitrided by plasma. Different samples were tested: untreated and plasma nitrided samples. The corrosion behaviour was evaluated by electrochemical techniques (potentiodynamic curves and electrochemical impedance spectroscopy). The corrosion tests were carried out in acid chloride solution 1M. The best corrosion protection was observed for samples nitrided.

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“…36) Usually, gЈ-Fe 4 N forms a kink of coarse needle-like precipitates dispersed in the ferritic matrix. 13) For the conventional nitriding, gЈ-Fe 4 N and e-Fe 2ϳ3 N are present in nitrided layers. The formation of z-Fe 2 N during nitriding is reported.…”

Section: Nitridingmentioning

confidence: 99%

“…2,3) To improve the surface hardness, wear and corrosion resistance, fatigue life, as well as global mechanical performance of pure iron and simple iron alloys, nitriding has been widely used in industries. Many nitriding processes have been applied to pure iron and low carbon steels, for instance, gas nitriding, [4][5][6][7][8][9][10] salt bath nitriding, 11) plasma nitriding, 10,[12][13][14][15][16] plasma immersion ion implantation (PIII), [16][17][18][19][20] laser nitriding, [21][22][23][24][25] and ion implantation nitriding. 26) Although the above methods are well established, some of them such as modern nitriding techniques still have some disadvantages from an engineering viewpoint because they require the use of rather complicated and expensive apparatus, and cannot, in general, produce thick nitrided layers.…”

Section: Introductionmentioning

confidence: 99%

Nitriding of Interstitial Free Steel in Potassium–Nitrate Salt Bath

Shen

Lee

2006

ISIJ Int.

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A study has been made of nitriding of interstitial free (IF) steel in the potassium-nitrate salt bath at temperatures ranging from 400 to 650°C. The salt is decomposed to generate nitrogen and oxygen. Nitrogen diffuses into steel, or steel is nitrided, while oxygen reacts on steel surface to form the oxide scale. The oxide scale thickness is much smaller than the nitriding thickness. Most of nitrogen resides in steel as a form of interstitial solid-solution. For nitriding at higher temperatures, nitride precipitates (gЈ-Fe 4 N and zЈ-Fe 2 N) exist mostly in grain boundaries and partly in grains of the steel. The nitrate nitriding gives rise to much larger nitriding depth than other nitriding methods at similar nitriding temperature and time. The nitrate nitriding of steel substantially increase its tensile strength as well as hardness, e.g., an IF steel specimen nitrided at 650°C for 1.5 h shows a tensile strength of 916 MPa, which is 2.2 times higher than that of non-nitrided IF steel specimen, and an elongation of 20 % at 70°C. Severe serrations are observed in flow curves of nitrided steel specimens, mainly due to dynamic strain aging that occurs because of interaction between dissolved nitrogen and moving dislocations. The effective diffusion coefficient of nitrogen D N obtained from the nitriding data, D N ϭD 0 exp(ϪQ/RT ) with D 0 ϭ3.789ϫ10 Ϫ7 m 2 · s Ϫ1 and Qϭ76.62 kJ mol Ϫ1, is approximately the same as that for diffusion of nitrogen in a-iron. (5) Reaction (2) has been observed at temperatures ranging from 517 to 537°C. 28) In addition, potassium nitrate may also directly decompose into potassium oxide 30,34,35) according to the following reaction (6) or (7) (7) Thus, the thermal decomposition of KNO 3 on heating can liberate nascent nitrogen and the nascent nitrogen can diffuse into the steel coupon. Therefore, there is a possibility of nitriding in the liquid KNO 3 salt bath under ambient pressure.Interstitial-free (IF) steels are ultra low carbon and nitrogen steels manufactured by adding carbide, nitride and sulphide-forming elements such as titanium and aluminum to form precipitates such as TiC, TiN, AlN, and TiS, leading to an elimination of the nitrogen, carbon and sulphur elements from the solid solution like nearly pure iron. For this reason, in order to investigate the effect of solid-solution strengthening by diffusion of nitrogen to the interstitial sites of a-Fe lattice when KNO 3 salt bath is used as nitriding of iron and steels, we chose to use a TiϩAl stabilized IF steel, in which Ti and Al scavenge both carbon and nitrogen.The purpose of this study is to investigate nitriding behavior of IF steel in the KNO 3 salt-bath, with emphasis on solid-solution hardening and nitriding kinetics. Experimental ProceduresA hot-rolled IF steel sheet of 4 mm in thickness was used as the initial material. The chemical composition of the steel is given in Table 1. The sheet was cold-rolled by 10, 30, and 75 % in thickness under lubrication.Extra pure potassium nitrate (99.0 wt% min. purity) with impurit...

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Characterization of plasma-nitrided iron by XRD, SEM and XPS

Cited by 84 publications

References 21 publications

TRIBOLOGICAL BEHAVIOR OF 42CrMo4 STEEL NITRIDED BY PLASMA

TRIBOLOGICAL BEHAVIOR OF 42CrMo4 STEEL NITRIDED BY PLASMA

Corrosion behaviour of the 42CrMo4 Steel Nitrided by Plasma

Nitriding of Interstitial Free Steel in Potassium–Nitrate Salt Bath

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Characterization of plasma-nitrided iron by XRD, SEM and XPS

Cited by 84 publications

References 21 publications

TRIBOLOGICAL BEHAVIOR OF 42CrMo4 STEEL NITRIDED BY PLASMA

TRIBOLOGICAL BEHAVIOR OF 42CrMo4 STEEL NITRIDED BY PLASMA

Corrosion behaviour of the 42CrMo4 Steel Nitrided by Plasma

Nitriding of Interstitial Free Steel in Potassium&ndash;Nitrate Salt Bath

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Nitriding of Interstitial Free Steel in Potassium–Nitrate Salt Bath