Nitriding of an austenitic stainless steel in plasma torch at atmospheric pressure

Abstract In this article, the results of thermal and chemical resistance, of plasma sprayed Al2O3 and Al2O3-13wt.TiO2 coatings on a steel (P265GH) sample are presented. Coatings were formed using air-hydrogen plasma direct current plasma torch at atmospheric pressure. The resistance of coatings was measured by analyzing surface structure, elemental and phase composition of as sprayed coatings and after several heating cycles, imitating application conditions. To make this technology more appealing, by decreasing exploitation cost of standard cast iron grate used in straw pellet broilers, we used cheaper stainless steel with a protective Al2O3 and Al2O3-13wt.% TiO2 coatings. Most of the research done in this field is by using Ar as primary gas, but to decrease the manufacturing cost even further we used Air as primary gas. It was determined that after heat treatment the minor changes in the elemental composition were observed. Meanwhile an additional crystalline phases of metal oxides were detected.

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Thermal And Chemical Resistance Of Plasma Sprayed Al2o3, Al2o3-Tio2 Coatings

10.21203/rs.3.rs-18422/v1 ◽

2020 ◽

Author(s):

Airingas Šuopys ◽

Liutauras Marcinauskas ◽

Romualdas Kėželis ◽

Mindaugas Aikas ◽

Rolandas Uscila

Keyword(s):

Heat Treatment ◽

Stainless Steel ◽

Atmospheric Pressure ◽

Plasma Torch ◽

Chemical Resistance ◽

Hydrogen Plasma ◽

Manufacturing Cost ◽

Direct Current Plasma ◽

Plasma Sprayed ◽

Sprayed Coatings

Abstract In this article, the results of thermal and chemical resistance, of plasma sprayed Al2O3 and Al2O3-13wt.TiO2 coatings on a steel (P265GH) sample are presented. Coatings were formed using air-hydrogen plasma direct current plasma torch at atmospheric pressure. The resistance of coatings was measured by analyzing surface structure, elemental and phase composition of as sprayed coatings and after several heating cycles, imitating application conditions. To make this technology more appealing, by decreasing exploitation cost of standard cast iron grate used in straw pellet broilers, we used cheaper stainless steel with a protective Al2O3 and Al2O3-13wt.% TiO2 coatings. Most of the research done in this field is by using Ar as primary gas, but to decrease the manufacturing cost even further we used Air as primary gas. It was determined that after heat treatment the minor changes in the elemental composition were observed. Meanwhile an additional crystalline phases of metal oxides were detected.

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Some aspects of the defect structure in an austenitic stainless steel

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100108714 ◽

1978 ◽

Vol 36 (1) ◽

pp. 314-315

Author(s):

R. Gonzalez ◽

L. Bru

Keyword(s):

Stainless Steel ◽

Austenitic Stainless Steel ◽

Cellular Structures ◽

Total Strain Amplitude ◽

Total Deformation ◽

Density Of Dislocations ◽

Planar Arrays ◽

Stacking Fault Tetrahedra ◽

Distribution Of Dislocations ◽

Very High

The analysis of stacking fault tetrahedra (SFT) in fatigued metals (1,2) is somewhat complicated, due partly to their relatively low density, but principally to the presence of a very high density of dislocations which hides them. In order to overcome this second difficulty, we have used in this work an austenitic stainless steel that deforms in a planar mode and, as expected, examination of the substructure revealed planar arrays of dislocation dipoles rather than the cellular structures which appear both in single and polycrystals of cyclically deformed copper and silver. This more uniform distribution of dislocations allows a better identification of the SFT.The samples were fatigue deformed at the constant total strain amplitude Δε = 0.025 for 5 cycles at three temperatures: 85, 293 and 773 K. One of the samples was tensile strained with a total deformation of 3.5%.

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A TEM microscopical investigation of the magnetic domain structure of a metastable austenitic stainless steel

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100171213 ◽

1994 ◽

Vol 52 ◽

pp. 696-697

Author(s):

G. Fourlaris ◽

T. Gladman

Keyword(s):

Tensile Strength ◽

Stainless Steel ◽

Austenitic Stainless Steel ◽

Cold Rolling ◽

Solution Treatment ◽

Magnetic Domain ◽

High Strength ◽

Medium Carbon Steel ◽

Magnetic Characteristics ◽

Metastable Austenitic Stainless Steel

Stainless steels have widespread applications due to their good corrosion resistance, but for certain types of large naval constructions, other requirements are imposed such as high strength and toughness , and modified magnetic characteristics.The magnetic characteristics of a 302 type metastable austenitic stainless steel has been assessed after various cold rolling treatments designed to increase strength by strain inducement of martensite. A grade 817M40 low alloy medium carbon steel was used as a reference material.The metastable austenitic stainless steel after solution treatment possesses a fully austenitic microstructure. However its tensile strength , in the solution treated condition , is low.Cold rolling results in the strain induced transformation to α’- martensite in austenitic matrix and enhances the tensile strength. However , α’-martensite is ferromagnetic , and its introduction to an otherwise fully paramagnetic matrix alters the magnetic response of the material. An example of the mixed martensitic-retained austenitic microstructure obtained after the cold rolling experiment is provided in the SEM micrograph of Figure 1.

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