Behavior of carbon in low temperature plasma nitriding layer of austenitic stainless steel

Tsujikawa, Masato; Yamauchi, N.; Ueda, Nobuhiro; Sone, Takumi; Hirose, Yoshio

doi:10.1016/j.surfcoat.2004.08.179

Cited by 110 publications

(78 citation statements)

References 4 publications

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“…The proportion of ε increased if compared to the condition without Methane (fifth diffractogram from bottom to top), but the γ' phase was still present and, consequently, it was not possible to produce the monophase ε on the surface of the samples. The results have shown that to obtain the pure ε in the compound layer of plasma nitrided steels is more complex than the way mentioned by O'Brien 19 and it's in accordance with other works that failed in the task of using this kind of gas to form such monophase 20,21 . Moreover, is shown the amount of ε phase in white layer (which is richer in N than γ' phase) depends directly on the N2 gas proportion.…”

Section: Microstructure Phase and Chemical Compositionsupporting

confidence: 88%

Metallurgical response of an AISI 4140 steel to different plasma nitriding gas mixtures

Skonieski

Santos

Hirsch³

et al. 2013

Mat. Res.

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Plasma nitriding is a surface modification process that uses glow discharge to diffuse nitrogen atoms into the metallic matrix of different materials. Among the many possible parameters of the process, the gas mixture composition plays an important role, as it impacts directly the formed layer's microstructure. In this work an AISI 4140 steel was plasma nitrided under five different gas compositions. The plasma nitriding samples were characterized using optical and scanning electron microscopy, microhardness test, X-ray diffraction and GDOES. The results showed that there are significant microstructural and morphological differences on the formed layers depending on the quantity of nitrogen and methane added to the plasma nitriding atmosphere. Thicknesses of 10, 5 and 2.5 µm were obtained when the nitrogen content of the gas mixtures were varied. The possibility to obtain a compound layer formed mainly by γ ' -Fe 4 N nitrides was also shown. For all studied plasma nitriding conditions, the presence of a compound layer was recognized as being the responsible to hinder the decarburization on the steel surface. The highest value of surface hardness -1277HV -were measured in the sample which were nitrided with 3vol.% of CH 4 .

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Section: Microstructure Phase and Chemical Compositionsupporting

confidence: 88%

Metallurgical response of an AISI 4140 steel to different plasma nitriding gas mixtures

Skonieski

Santos

Hirsch³

et al. 2013

Mat. Res.

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show abstract

“…[30] The diffusion layer is subdivided into zones 'b' and 'c'. Fraction 'b' is related to a zone of strong precipitation (instantaneous precipitation reaction); it consists of ferrite, and carbides probably combined with chromium and tungsten, which are not revealed by X-rays diffraction spectra.…”

Section: Microstructure and Diffusion Mechanismmentioning

confidence: 99%

Post‐oxidizing effects on surface characteristics of salt bath nitrocarburized AISI 02 tool steel type

Fares¹,

Chaoui²,

Coze³

2009

Surface & Interface Analysis

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The effect of post-oxidizing treatment on the characteristics of modified surface layers produced by salt bath nitrocarburizing on the industrial American Iron and Steel Institute (AISI) 02 tool steel types is investigated. Nitrocarburizing treatment is performed for 6 h and 8 h at 570• C and post-oxidizing treatment for 30, 60 and 90 min at 520 • C, using argon-steam mixture. Formed layers are characterized by their basic properties such as thickness layer, depth, surface hardness and wear resistance. Detailed estimation of the modified metal surface quality, in terms of chemical composition, formed phases, microstructures and diffusion mechanisms are performed by metallographic techniques, EDX, X-ray diffraction, scanning electron microscopy (SEM) and glow discharge optical electron spectroscopy (GDOES). The corrosion resistance was investigated in 0.4 M H 2 SO 4 solutions, using steady-state electrochemical polarization methods. The obtained results revealed the existence of a superficial oxide layer which consists of magnetite (Fe 3 O 4 ) and hematite (Fe 2 O 3 ) and the presence of an ε-phase associated with a small amount of γ -phase. Important improvements in wear, microhardness and corrosion resistance occur after these treatments and it is specifically concluded that the sole application of a nitrocarburizing treatment does not significantly ameliorate the corrosion resistance of the as-received steel. In fact, post-oxidation treatment contributes to increase corrosion resistance by forming a dense magnetite layer and at the same time, it partially covers the compound layer pores.

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“…A small peak of carbon is visible at the subsurface layer. 13) The simultaneously carburized and nitrided specimen 8(C+N), as shown in Fig. 4(c), displayed high accumulation of carbon beyond the nitrided layer.…”

Section: Resultsmentioning

confidence: 93%

“…Figure 4 shows elemental depth profiles of plasmaprocessed specimens. The carbon push-ahead effect of incoming nitrogen 13,17) is clearly visible in Figs. 4(a) and (d).…”

Section: Resultsmentioning

confidence: 93%

“…Sequential carburizing and nitriding produce clear duplex surface layers. 13) The flexibility of design for an austenitic stainless steel surface layer would be wider if we were able to control the location of the carburized layer using this carbon push-ahead effect by nitriding. This study seeks to determine the optimum surface structure by controlling the microstructure using various combinations of carburizing and nitriding.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Surface Modification of SUS304 Stainless Steel Using Carbon Push-Ahead Effect by Low Temperature Plasma Nitriding

et al. 2005

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Low temperature nitriding can harden the steel surface. However, the consequent thickness is limited because it depends on the formation of non-equilibrium phase at low temperature diffusion treatment. The hardness drops abruptly at the interface between the treated layer and the substrate as a result of nitriding. In this paper, duplex surface layers produced by combinations of carburizing and nitriding were developed using the carbon push-ahead effect of nitriding using relatively low-temperature plasma treatment. The location of the low-temperature carburized layer was pushed ahead following nitriding to form a support layer for a hard nitrided surface layer. The treatment combination was optimized for a thicker hard layer with good corrosion resistance.

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Behavior of carbon in low temperature plasma nitriding layer of austenitic stainless steel

Cited by 110 publications

References 4 publications

Metallurgical response of an AISI 4140 steel to different plasma nitriding gas mixtures

Metallurgical response of an AISI 4140 steel to different plasma nitriding gas mixtures

Post‐oxidizing effects on surface characteristics of salt bath nitrocarburized AISI 02 tool steel type

Surface Modification of SUS304 Stainless Steel Using Carbon Push-Ahead Effect by Low Temperature Plasma Nitriding

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