Mechanism of ion nitriding of 316L austenitic steel by active screen method in a hydrogen-nitrogen atmosphere

The study assessed the effect of ion nitriding on the properties of the surface layer of Grade 5 titanium alloy used, among others, in medicine. Titanium and its alloys have low hardness and insufficient wear resistance in conditions of friction which limits the use of these materials. The improvement of these properties is only possible by the appropriate modification of the surface layer of these alloys. The ion nitriding process was carried out in a wide temperature range, i.e., 530–590 °C, and in the time range 5–17 h. Two variants of nitriding were applied: cathodic (conventional) nitriding and nitriding using the active screen method. The research results presented in this article allow for stating that each of the applied nitriding variants improves the analysed properties (nitrogen diffusion depth, hardness, wear resistance, microstructure analysis and surface topography) of the surface layers in relation to the material before nitriding. The hardness increased in every nitriding variant (the use of the additional active screen increased the hardness to 1021 HK0.025). The greatest increase in titanium abrasion resistance was found for surfaces after cathodic nitriding with an active screen. Each of the applied nitriding variants resulted in surface development.

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Mechanical Properties of Nitrided STS 431 Martensitic Stainless Steel by the Active Screen Ion Nitriding

Journal of the Korean institute of surface engineering ◽

10.5695/jkise.2011.44.4.149 ◽

2011 ◽

Vol 44 (4) ◽

pp. 149-154 ◽

Cited By ~ 1

Author(s):

Hyun-Bae Bang ◽

Uoo-Chang Jung ◽

Won-Sub Jung ◽

Byung-Chul Cha

Keyword(s):

Mechanical Properties ◽

Stainless Steel ◽

Martensitic Stainless Steel ◽

Ion Nitriding ◽

Active Screen

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Influence of ion nitriding regime on mechanical properties and fracture mechanism of austenitic steel subjected to different thermomechanical treatments

10.1063/1.4966452 ◽

2016 ◽

Author(s):

Valentina Moskvina ◽

Elena Astafurova ◽

Kamil Ramazanov ◽

Eugene Melnikov ◽

Galina Maier ◽

...

Keyword(s):

Mechanical Properties ◽

Austenitic Steel ◽

Fracture Mechanism ◽

Ion Nitriding

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Ion nitriding of austenitic steel articles

Metal Science and Heat Treatment ◽

10.1007/bf00775026 ◽

1991 ◽

Vol 33 (1) ◽

pp. 15-16

Author(s):

A. B. Arzamasov

Keyword(s):

Austenitic Steel ◽

Ion Nitriding

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Application Of Active Screen Method For Ion Nitriding Efficiency Improvement

Archives of Metallurgy and Materials ◽

10.1515/amm-2015-0262 ◽

2015 ◽

Vol 60 (2) ◽

pp. 1075-1077 ◽

Cited By ~ 1

Author(s):

M. Ogórek ◽

T. Frączek ◽

Z. Skuza

Keyword(s):

Austenitic Steel ◽

Emission Spectroscopy ◽

Surface Hardness ◽

Efficiency Improvement ◽

Nitrogen Diffusion ◽

Ion Nitriding ◽

Aisi 304 ◽

Hardness Tests ◽

Steel Aisi ◽

Surface Layer Thickness

Abstract Paper presents the research of austenitic steel AISI 304 after ion nitriding at 400°C and at t =4h, for the two different variants of samples distribution in the working plasma reactive chamber tube. In order to assess the effectiveness of ion nitriding variants emission spectroscopy – GDOES, surface hardness tests, microstructure research (LM) of nitrided layers were made. It has been found that the use of active screens increases the surface layer thickness and depth of nitrogen diffusion into austenitic steel 304.

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Novel magneto-optical recording materials: Bi-substituted garnet films

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100088191 ◽

1991 ◽

Vol 49 ◽

pp. 776-777

Author(s):

Takao Suzuki ◽

Hossein Nuri

Keyword(s):

Grain Size ◽

Amorphous Film ◽

Nitrogen Atmosphere ◽

Optical Recording ◽

Garnet Film ◽

Media Noise ◽

Garnet Films ◽

Order Of Magnitude ◽

A New Technique ◽

A Current

For future high density magneto-optical recording materials, a Bi-substituted garnet film ((BiDy)3(FeGa)5O12) is an attractive candidate since it has strong magneto-optic effect at short wavelengths less than 600 nm. The signal in read back performance at 500 nm using a garnet film can be an order of magnitude higher than a current rare earth-transition metal amorphous film. However, the granularity and surface roughness of such crystalline garnet films are the key to control for minimizing media noise.We have demonstrated a new technique to fabricate a garnet film which has much smaller grain size and smoother surfaces than those annealed in a conventional oven. This method employs a high ramp-up rate annealing (Γ = 50 ~ 100 C/s) in nitrogen atmosphere. Fig.1 shows a typical microstruture of a Bi-susbtituted garnet film deposited by r.f. sputtering and then subsequently crystallized by a rapid thermal annealing technique at Γ = 50 C/s at 650 °C for 2 min. The structure is a single phase of garnet, and a grain size is about 300A.

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Spherulite Structures in a Melt Spun Fe-Ni Austenitic Steel

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100117339 ◽

1985 ◽

Vol 43 ◽

pp. 52-53

Author(s):

G. M. Michal ◽

T. K. Glasgow ◽

T. J. Moore

Keyword(s):

Austenitic Steel ◽

Room Temperature ◽

Elevated Temperatures ◽

Large Range ◽

Amorphous Structure ◽

Nucleation And Growth ◽

Ni Alloys ◽

Melt Spun ◽

Crystal Fibers ◽

Rapidly Solidified

Large additions of B to Fe-Ni alloys can lead to the formation of an amorphous structure, if the alloy is rapidly cooled from the liquid state to room temperature. Isothermal aging of such structures at elevated temperatures causes crystallization to occur. Commonly such crystallization pro ceeds by the nucleation and growth of spherulites which are spherical crystalline bodies of radiating crystal fibers. Spherulite features were found in the present study in a rapidly solidified alloy that was fully crysstalline as-cast. This alloy was part of a program to develop an austenitic steel for elevated temperature applications by strengthening it with TiB2. The alloy contained a relatively large percentage of B, not to induce an amorphous structure, but only as a consequence of trying to obtain a large volume fracture of TiB2 in the completely processed alloy. The observation of spherulitic features in this alloy is described herein. Utilization of the large range of useful magnifications obtainable in a modern TEM, when a suitably thinned foil is available, was a key element in this analysis.

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Extraction and identification of fillers and pigments from pyrolyzed rubber and tire samples

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100163332 ◽

1996 ◽

Vol 54 ◽

pp. 174-175

Author(s):

P. Sadhukhan ◽

J. B. Zimmerman

Keyword(s):

Zinc Oxide ◽

Electron Microscope ◽

Carbon Black ◽

Natural Rubber ◽

Transmission Electron Microscope ◽

Rolling Resistance ◽

Synthetic Polymers ◽

Nitrogen Atmosphere ◽

Transmission Electron ◽

Curing Agents

Rubber stocks, specially tires, are composed of natural rubber and synthetic polymers and also of several compounding ingredients, such as carbon black, silica, zinc oxide etc. These are generally mixed and vulcanized with additional curing agents, mainly organic in nature, to achieve certain “designing properties” including wear, traction, rolling resistance and handling of tires. Considerable importance is, therefore, attached both by the manufacturers and their competitors to be able to extract, identify and characterize various types of fillers and pigments. Several analytical procedures have been in use to extract, preferentially, these fillers and pigments and subsequently identify and characterize them under a transmission electron microscope.Rubber stocks and tire sections are subjected to heat under nitrogen atmosphere to 550°C for one hour and then cooled under nitrogen to remove polymers, leaving behind carbon black, silica and zinc oxide and 650°C to eliminate carbon blacks, leaving only silica and zinc oxide.

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A study of oxygen and vacancy ordering in YBa2Cu3O7−x

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100152793 ◽

1989 ◽

Vol 47 ◽

pp. 164-165

Author(s):

Y. P. Lin ◽

A. H. O’Reilly ◽

J. E. Greedan ◽

M. Post

Keyword(s):

Electron Microscopy ◽

Neutron Diffraction ◽

Oxygen Content ◽

Carbon Film ◽

Nitrogen Atmosphere ◽

Vacancy Ordering ◽

Powder Samples ◽

Vacancy Chains ◽

Chain Ordering

In the basal planes of the orthorhombic YBa2Cu3O7-X compound with x=0.07, which has a Tc of around 90K, chains of copper-oxygen are formed along the [010] direction. Previous investigations on the variation of Tc with oxygen content have shown the existence of a plateau at Tc = 60K for x=0.3 to 0.4, suggesting the presence of a separate phase. This phase has also been identified to be orthorhombic, but with a 2x superlattice along [100] of the parent structure, and the superlattice has been attributed to the formation of alternating copper-oxygen and copper-vacancy chains. In our work, we have studied the chain ordering phenomenon by electron microscopy and neutron diffraction on samples with different oxygen contents. We report here some of our electron microscopy findings for samples with x=0.4.Powder samples of YBa2Cu3O7-X were prepared by controlled re-oxidation of previously reduced material. For electron microscopy, the sample was dry ground using a mortar and pestle in a dry nitrogen atmosphere without the use of any solvent and transferred dry onto holey carbon film for examination in a Philips CM12 microscope.

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