Effect of Deformation Structure of AISI 316L in Low-Temperature Vacuum Carburizing

The effect of plastic deformation applied to AISI 316L in low-temperature vacuum carburizing without surface activation was investigated. To create a difference in the deformation states of each specimen, solution and stress-relieving heat treatment were performed using plastically deformed AISI 316L, and the deformation structure and the carburized layer were observed with EBSD and OM. The change in lattice parameter was confirmed with XRD, and the natural oxide layers were analyzed through TEM and XPS. In this study, the carburized layer on the deformed AISI 316L was the thinnest and the dissolved carbon content of the layer was the lowest. The thickness and composition of the natural oxide layer on the surface were changed due to the deformed structure. The natural oxide layer on the deformed AISI 316L was the thickest, and the layer was formed with a bi-layer structure consisting of an upper Cr-rich layer and a lower Fe-rich layer. The thick and Cr-rich oxide layer was difficult to decompose due to the requirement for lower oxygen partial pressure. In conclusion, the oxide layer is the most influential factor, and its thickness and composition may determine carburizing efficiency in low-temperature vacuum carburizing without surface activation.

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Effect of Adjusted Gas Nitriding Parameters on Microstructure and Wear Resistance of HVOF-Sprayed AISI 316L Coatings

Materials ◽

10.3390/ma12111760 ◽

2019 ◽

Vol 12 (11) ◽

pp. 1760 ◽

Cited By ~ 5

Author(s):

Pia Kutschmann ◽

Thomas Lindner ◽

Kristian Börner ◽

Ulrich Reese ◽

Thomas Lampke

Keyword(s):

Wear Resistance ◽

Low Temperature ◽

Process Management ◽

Surface Activation ◽

Aisi 316L ◽

Spray Coatings ◽

Gas Nitriding ◽

Surface Distance ◽

Diffusion Depth ◽

Sprayed Coating

Gas nitriding is known as a convenient process to improve the wear resistance of steel components. A precipitation-free hardening by low-temperature processes is established to retain the good corrosion resistance of stainless steel. In cases of thermal spray coatings, the interstitial solvation is achieved without an additional surface activation step. The open porosity permits the penetration of the donator media and leads to a structural diffusion. An inhomogeneous diffusion enrichment occurs at the single spray particle edges within the coating’s microstructure. A decreasing diffusion depth is found with increasing surface distance. The present study investigates an adjusted process management for low-temperature gas nitriding of high velocity oxy-fuel-sprayed AISI 316L coatings. To maintain a homogeneous diffusion depth within the coating, a pressure modulation during the process is studied. Additionally, the use of cracked gas as donator is examined. The process management is designed without an additional surface activation step. Regardless of surface distance, microstructural investigations reveal a homogeneous diffusion depth by a reduced processing time. The constant hardening depth allows a reliable prediction of the coatings’ properties. An enhanced hardness and improved wear resistance is found in comparison with the as-sprayed coating condition.

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The observation of the structure of the natural oxide layer on a Cr(110) surface by scanning tunnelling microscopy

Surface Science ◽

10.1016/0039-6028(90)90644-n ◽

1990 ◽

Vol 233 (3) ◽

pp. 317-322 ◽

Cited By ~ 33

Author(s):

Norman M.D. Brown ◽

Hong-Xing You

Keyword(s):

Oxide Layer ◽

Scanning Tunnelling Microscopy ◽

Natural Oxide Layer ◽

Scanning Tunnelling ◽

Natural Oxide ◽

Tunnelling Microscopy

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Structure and Thickness of Natural Oxide Layer on Ultrafine Particle

Japanese Journal of Applied Physics ◽

10.1143/jjap.42.7489 ◽

2003 ◽

Vol 42 (Part 1, No. 12) ◽

pp. 7489-7492 ◽

Cited By ~ 21

Author(s):

Koichi Tamura ◽

Yuki Kimura ◽

Hitoshi Suzuki ◽

Osamu Kido ◽

Takeshi Sato ◽

...

Keyword(s):

Oxide Layer ◽

Ultrafine Particle ◽

Natural Oxide Layer ◽

Natural Oxide

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Analyses about the influence of the natural oxide layer of aluminium on the brazeability in a shielding gas furnace

Welding in the World ◽

10.1007/s40194-013-0031-9 ◽

2013 ◽

Vol 57 (4) ◽

pp. 449-455 ◽

Cited By ~ 3

Author(s):

Julia Zähr ◽

Hans-Jürgen Ullrich ◽

Steffen Oswald ◽

Matthias Türpe ◽

U. Füssel

Keyword(s):

Oxide Layer ◽

Shielding Gas ◽

Natural Oxide Layer ◽

Natural Oxide

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A Chemical-State-Specific Study of the Composition of the Natural Oxide Layer of V$_{25}$Cr$_{40}$Ti$_{35}$

Applied Physics Express ◽

10.1143/apex.5.031802 ◽

2012 ◽

Vol 5 (3) ◽

pp. 031802 ◽

Cited By ~ 1

Author(s):

James R. Harries ◽

Yuden Teraoka ◽

Mayumi Tode ◽

Akitaka Yoshigoe

Keyword(s):

Oxide Layer ◽

Chemical State ◽

Specific Study ◽

Natural Oxide Layer ◽

Natural Oxide

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Pressureless Low-Temperature Sintering of Silver Nano-Solder Paste Based on Surface Activation

2019 20th International Conference on Electronic Packaging Technology(ICEPT) ◽

10.1109/icept47577.2019.245126 ◽

2019 ◽

Author(s):

Te Wang ◽

Chenxi Wang ◽

Hui Fang ◽

Qiushi Kang ◽

Rong An ◽

...

Keyword(s):

Low Temperature ◽

Surface Activation ◽

Low Temperature Sintering ◽

Solder Paste

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Acetylene Flow Rate as a Crucial Parameter of Vacuum Carburizing Process of Modern Tool Steels

Archives of Metallurgy and Materials ◽

10.1515/amm-2016-0324 ◽

2016 ◽

Vol 61 (4) ◽

pp. 2009-2012 ◽

Cited By ~ 4

Author(s):

P. Rokicki ◽

K. Dychton

Keyword(s):

Chemical Treatment ◽

Negative Impact ◽

Aerospace Industry ◽

Tool Steels ◽

Vacuum Carburizing ◽

Layer Characteristic ◽

Process Methodology ◽

Carburized Layer ◽

Treatment Procedures ◽

Carburizing Process

Abstract Carburizing is one of the most popular and wide used thermo-chemical treatment methods of surface modification of tool steels. It is a process based on carbon diffusive enrichment of the surface material and is applied for elements that are supposed to present higher hardness and wear resistance sustaining core ductility. Typical elements submitted to carburizing process are gears, shafts, pins and bearing elements. In the last years, more and more popular, especially in highly advanced treatment procedures used in the aerospace industry is vacuum carburizing. It is a process based on chemical treatment of the surface in lower pressure, providing much higher uniformity of carburized layer, lower process cost and much lesser negative impact on environment to compare with conventional carburizing methods, as for example gas carburizing in Endo atmosphere. Unfortunately, aerospace industry requires much more detailed description of the phenomena linked to this process method and the literature background shows lack of tests that could confirm fulfilment of all needed requirements and to understand the process itself in much deeper meaning. In the presented paper, authors focused their research on acetylene flow impact on carburized layer characteristic. This is one of the most crucial parameters concerning homogeneity and uniformity of carburized layer properties. That is why, specific process methodology have been planned based on different acetylene flow values, and the surface layer of the steel gears have been investigated in meaning to impact on any possible change in potential properties of the final product.

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