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Evaluación del efecto de tratamientos térmicos de envejecido en aceros inoxidables C+B+N

Sarmiento Viracachá, Daniel Ricardo (BogotáIngeniería Mecánica, 2022)

En este artículo se identificó la evolución de la microestructura de un acero inoxidable modificado con B y N al aplicar tratamientos térmicos de envejecido artificial con diferentes tiempos de sostenimiento. Se encontró ...
Fracture resistant and wear corrosion performance of CrN/ZrN bilayers deposited onto AISI 420 stainless steel

Alba de Sánchez, Nelly Cecilia; Jaramillo, Henry E.; Vivas, Zulima; Aperador Chaparro, William Arnulfo; Caicedo, Julio Cesar; Amaya, Cesar; Jaramillo Suarez, Héctor Enrique (Suiza, 2008)

CrN/ZrN (1, 8, 15, and 30) bilayers were deposited onto AISI 420 steel substrates at 250°C and 6.6x10-3 mbar with gas ratio Ar/N2 50:3.0 as gas mixture and bias -60V were applied. AFM analysis presented different morphologies, ...
Performance of Nozzle Steels in Biofuel

Blanco Estupiñan, David Leonardo; Bermudez-Castañeda, Angela; Márquez, Sebastian (Pontificia Universidad JaverianaBogotá (Colombia), 2022)

To evaluate the corrosion resistance of stainless-steel injection nozzles under immersion test in biodiesel and perform electrochemical characterization under HNO3 solutions. Methods and materials: Chemical characterization ...

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Evaluación del efecto de tratamientos térmicos de envejecido en aceros inoxidables C+B+N
...
Sarmiento Viracachá, Daniel Ricardo | 2022

En este artículo se identificó la evolución de la microestructura de un acero inoxidable modificado con B y N al aplicar tratamientos térmicos de envejecido artificial con diferentes tiempos de sostenimiento. Se encontró que la dureza general del acero disminuyó entre 0,4 y 15 puntos HRC con el aumento en el tiempo de sostenimiento del envejecido; Sugiriendo dos posibles comportamientos, el primero por un crecimiento en los precipitados de aproximadamente un orden de magnitud con respecto al tamaño optimo reportado en la literatura, y el segundo por la formacion de fases de bajas propiedades mecánicas como la fase sigma. El presente estudio permite concluir que la composición planteada para el acero hace que sea sensible a la temperatura debido a la pérdida acelerada de la dureza con los diferentes tratamientos térmicos aplicados.

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Fracture resistant and wear corrosion performance of CrN/ZrN bilayers deposited onto AISI 420 stainless steel
...
Alba de Sánchez, Nelly Cecilia | 2008

CrN/ZrN (1, 8, 15, and 30) bilayers were deposited onto AISI 420 steel substrates at 250°C and 6.6x10-3 mbar with gas ratio Ar/N2 50:3.0 as gas mixture and bias -60V were applied. AFM analysis presented different morphologies, showing that the coatings with 15 bilayers had an average grain size of 49 nm; while the 30-bilayer coating exhibited grain sizes of 99 nm. Coating thicknesses were 3 µm, approximately. The Vickers Test revealed that coatings with 8, 15, and 30 bilayers bore better impact resistance than coatings with 1 bilayer. This result is considered, bearing in mind that in many bilayers propagation of fissures is slower, because the presence of layer inter-phases leads to fissures straying in other directions. Slight corrosion specks are present, but mass loss was around 40 mg. in one bilayer, a higher value than for the coatings with 15 bilayers that was near 18 mg. Homogeneity, grain size, fracture resistance, and corrosion resistance of the coatings with 15 and 30 bilayers are suitable for mechanical applications of these types of coatings, as shown in mechanical measurements. These results indicate that for engineering applications under corrosive environments, the use of these types of bilayer coatings on AISI 420 stainless steel is highly recommended.

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Performance of Nozzle Steels in Biofuel
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Blanco Estupiñan, David Leonardo | 2022

To evaluate the corrosion resistance of stainless-steel injection nozzles under immersion test in biodiesel and perform electrochemical characterization under HNO3 solutions. Methods and materials: Chemical characterization of biofuel was performed to analyze its stability. Immersion tests were carried out for 4 months, evaluating 304 stainless steel under 3 different diesel/biofuel mixtures concentrations. Additionally, polarization tests were done using NOx concentrations above the levels measured from engine emissions. Results and discussion: The use of biofuels in Colombia has been largely driven by ethanol production from vegetable sources. Their use brings some advantages related to reducing emissions of particles and toxic gases (mainly aromatic groups, NOx, and CO2). However, degradation of materials can occur when they are in direct contact with biodiesel. Furthermore, solidification into waxes, which leads to plugging of nozzles, has been reported. However, it is unknown whether this influences oxygen diffusion in the solution and, in turn, affects the corrosion resistance of stainless steel. Conclusions: The corrosion resistance of the 304 stainless steel changed under immersion conditions, even though its protective layer was not affected by the NOx concentrations registered in the biofuel mixtures.

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Listar por tema "Stainless steel"

Evaluación del efecto de tratamientos térmicos de envejecido en aceros inoxidables C+B+N

Fracture resistant and wear corrosion performance of CrN/ZrN bilayers deposited onto AISI 420 stainless steel

Performance of Nozzle Steels in Biofuel

Envíos recientes

Evaluación del efecto de tratamientos térmicos de envejecido en aceros inoxidables C+B+N

Fracture resistant and wear corrosion performance of CrN/ZrN bilayers deposited onto AISI 420 stainless steel

Performance of Nozzle Steels in Biofuel

Listar por tema "Stainless steel"

Evaluación del efecto de tratamientos térmicos de envejecido en aceros inoxidables C+B+N ﻿

Fracture resistant and wear corrosion performance of CrN/ZrN bilayers deposited onto AISI 420 stainless steel ﻿

Performance of Nozzle Steels in Biofuel ﻿

Envíos recientes

Evaluación del efecto de tratamientos térmicos de envejecido en aceros inoxidables C+B+N

Fracture resistant and wear corrosion performance of CrN/ZrN bilayers deposited onto AISI 420 stainless steel

Performance of Nozzle Steels in Biofuel

Evaluación del efecto de tratamientos térmicos de envejecido en aceros inoxidables C+B+N

Fracture resistant and wear corrosion performance of CrN/ZrN bilayers deposited onto AISI 420 stainless steel

Performance of Nozzle Steels in Biofuel