scholarly journals The Atmosphere’s Effect on Stainless Steel Slabs’ Oxide Formation in a CH4-Fuelled Reheating Furnace

Metals ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 621
Author(s):  
Aleksi Laukka ◽  
Eetu-Pekka Heikkinen ◽  
Timo Fabritius
Keyword(s):  
Stainless Steel ◽  
Oxide Layer ◽  
Depth Profiling ◽  
Layer Growth ◽  
304 Stainless Steel ◽  
Oxide Growth ◽  
Breakaway Oxidation ◽  
Positive Effects ◽  
Steel Slab ◽  
Single Temperature

Utilising the oxyfuel practice for CH4-fuelled combustion has positive effects on the emissions, efficiency and cost of high temperature furnace practices. However, especially in older installations, oxyfuel usage requires retrofitting and alters the atmosphere in which the oxidation of the steel occurs, when compared to using air as the oxidiser. Stainless steel slab oxide growth during reheating was studied in different atmospheres. The simulated post-burn atmospheres from oxyfuel, lean oxyfuel and air-fuel practices were used to compare oxide-scale layer growth and morphology during simulated typical AISI 304 stainless steel slab reheating prior to hot rolling. Thermogravimetric measurements, glow discharge optical emission spectrometer (GDOES) and field-emission scanning electron microscope energy dispersive X-ray (FESEM-EDS) methodology were applied to discern differences between oxide growth and inner oxide layer morphology between the three practices. Switching from air to oxyfuel practice at a single temperature had the same increasing effect on the scale formation amount as a 25 °C temperature increase in air atmosphere. Inner oxide layer depth profiling revealed C, Si and Ni to be the main elements that differed between temperatures and atmospheres. A morphology study showed Si and Ni behaviour to be linked to breakaway oxidation.

Effects of Nitrogen Ion Implantation in 304 Stainless Steel at High Temperatures

1989 ◽  
Vol 157 ◽  
Author(s):  
Sadhna Shrivastava ◽  
Ram D. Tarey ◽  
M.C. Bhatnager ◽  
Amttaeh Jain ◽  
K.L. Chopra
Keyword(s):  
Stainless Steel ◽  
Oxide Layer ◽  
Depth Profiling ◽  
304 Stainless Steel ◽  
Beam Power ◽  
Target Temperature ◽  
X Ray Diffraction ◽  
Glancing Angle ◽  
Nitrogen Ion ◽  
Complete Precipitation

ABSTRACTWe studied the effect of varying the target temperature (by changing the beam power) on the structure and properties of nitrogen ion implanted 304 stainless steel. With a beam power of 0.1 W/ cm2 the target temperature is restricted to 150°C. After a dose of 3. 5x1017N2+/cm2 the microhardness measured at 10g increases by 15%. With a beam power of 1.1 W/cm2 the target temperature is 500°C. After the same dose as before, the irdcrohardness increase is 40%. Glancing Angle X-ray Diffraction and Auger depth profiling results suggest that the increased hardness is due to the presence of nitrogen in solution as opposed to complete precipitation. A sample deformed by compression formed an enhanced oxide layer during implantation. This oxide layer appears to have a capping action against the out-diffusion of nitrogen.

Oxidation behavior of TiN with a Ti interlayer on stainless steel

2004 ◽  
Vol 819 ◽  
Author(s):  
Ming-Hua Shiao ◽  
Ching-Chiun Wang ◽  
Chien-Ying Su ◽  
Fuh-Sheng Shieu
Keyword(s):  
Stainless Steel ◽  
Steel Substrate ◽  
Depth Profiling ◽  
Columnar Structure ◽  
304 Stainless Steel ◽  
Force Microscopy ◽  
Tin Coatings ◽  
Atomic Force ◽  
Transmission Electron ◽  
Tin Thin Films

AbstractCharacterization of the TiN coatings oxidized in air at temperatures at 600 and 700°C for 30 min was carried out by X-ray diffraction (XRD), atomic force microscopy (AFM), transmission electron microscopy (TEM) and Auger electron spectroscopy (AES). TiN thin films with a Ti interlayer were prepared by hollow cathode discharge ion plating on AISI 304 stainless steel. Both XRD and TEM results show that the TiN coatings and Ti interlayer have columnar structure with (111) and (0002) preferred orientations, respectively. AFM results show the existence of pinholes on the surface of specimens due to electropolishing process of the steel substrate, and the surface roughness (Ra) changes from 3.5 nm for the as-deposited specimen to 11.6 nm after oxidation at 700°. After oxidation, the TiO2 oxide layer formed on the specimen surface was porous and retained the columnar structure as the original TiN coating. The microstructure of the Ti interlayer gradually changed from columnar to polycrystalline structure due to grain growth. The Auger elemental depth profiling indicated that interdiffusion of the Ti interlayer with steel substrate had occurred during the oxidation process.

A New Interpretation of the ''Breakaway'' Oxidation Behaviour Observed at High Temperature on 304 Stainless Steel

2004 ◽  
Vol 461-464 ◽  
pp. 175-182 ◽  
Author(s):  
Frédéric Riffard ◽  
Henri Buscail ◽  
Eric Caudron ◽  
Régis Cueff ◽  
Christophe Issartel ◽  
...  
Keyword(s):  
Stainless Steel ◽  
High Temperature ◽  
Oxidation Behaviour ◽  
304 Stainless Steel ◽  
Breakaway Oxidation ◽  
New Interpretation

scholarly journals Kinetic investigation of AISI 304 Stainless Steel boronized in indirect heated fluidized bed furnace

2016 ◽  
Vol 52 (1) ◽  
pp. 63-68 ◽  
Author(s):  
P. Topuz ◽  
B. Çiçek ◽  
O. Akar
Keyword(s):  
Stainless Steel ◽  
Fluidized Bed ◽  
Optical Microscope ◽  
Boride Layer ◽  
Layer Growth ◽  
304 Stainless Steel ◽  
X Ray Diffraction ◽  
Aisi 304 Stainless Steel ◽  
Aisi 304 ◽  
Kinetics Of

In this study, kinetic examinations on boronized AISI 304 Stainless Steel samples were described. Samples were boronized in indirect heated fluidized bed furnace consists of Ekabor 1? boronizing agent at 1123, 1223 and 1323 K for 1,2 and 4 hours. Morphologically and typically examinations of borides formed on the surface of steel samples were studied by optical microscope, scanning electron microscope (SEM) and X-Ray diffraction (XRD). Boride layer thickness formed on the steel X5CrNi 18-10 ranges from 12 to 176 ?m. The hardness of the boride layer formed on the steel X5CrNi 18-10 varied between 1709 and 2119 Hv0,1. Layer growth kinetics were analyzed by measuring the extent of penetration of FeB and Fe2B sublayers as a function of boronizing time and temperature. The kinetics of the reaction has been determined with K=Ko exp (-Q/RT) equation. Activation energy (Q) of boronized steel X5CrNi 18-10 was determined as 244 kj/mol.

scholarly journals Effects of Surface Severe Plastic Deformation on the Mechanical Behavior of 304 Stainless Steel

Metals ◽  
2020 ◽  
Vol 10 (6) ◽  
pp. 831
Author(s):  
Yang Li ◽  
Zhengtong Lu ◽  
Tingchao Li ◽  
Dalei Li ◽  
Jinsheng Lu ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Residual Stress ◽  
Plastic Deformation ◽  
Stainless Steel ◽  
Severe Plastic Deformation ◽  
Mechanical Behavior ◽  
High Strength ◽  
304 Stainless Steel ◽  
Abrasive Waterjet ◽  
Positive Effects

In this study, two innovative surface severe plastic deformation (SSPD) methods, namely abrasive waterjet peening (AWJP) and ultrasonic nanocrystal surface modification (UNSM), were applied to a 304 stainless steel to improve the mechanical behavior. The surface roughness, microstructure, residual stress, hardness, and tensile mechanical properties of the alloy after the two SSPD treatments were studied systematically. The results show that both the AWJP and UNSM treatments have greatly positive effects on the mechanical-properties improvements by successfully introducing a hardening layer. Especially the UNSM-processed specimen possesses the most outstanding comprehensive mechanical properties (high strength with the comparable ductility). The yield strength with the UNSM treatment is 443 MPa, corresponding to the 109% and 19% improvements, as compared to that of the base (212 MPa) and AWJP-treated specimens (372 MPa). The results can be attributed to a much thicker hardening layer (about 500 μm) and a better surface integrity with lower roughness (Ra: 0.10 μm) formed by the UNSM technique.

scholarly journals Improvement of Corrosion Resistance of Stainless Steel Welded Joint Using a Nanostructured Oxide Layer

Nanomaterials ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 838
Author(s):  
Jun Heo ◽  
Sang Yoon Lee ◽  
Jaewoo Lee ◽  
Akram Alfantazi ◽  
Sung Oh Cho
Keyword(s):  
Stainless Steel ◽  
Corrosion Resistance ◽  
Oxide Layer ◽  
Electrochemical Impedance ◽  
304 Stainless Steel ◽  
Gas Tungsten Arc ◽  
Nanostructured Oxide ◽  
Corrosion Behaviors ◽  
Surface Morphologies ◽  
Type 304

In this study, we fabricated a nanoporous oxide layer by anodization to improve corrosion resistance of type 304 stainless steel (SS) gas tungsten arc weld (GTAW). Subsequent heat treatment was performed to eliminate any existing fluorine in the nanoporous oxide layer. Uniform structures and compositions were analyzed with field emission scanning electron microscope (FESEM) and X-ray diffractometer (XRD) measurements. The corrosion resistance of the treated SS was evaluated by applying a potentiodynamic polarization (PDP) technique and electrochemical impedance spectroscopy (EIS). Surface morphologies of welded SS with and without treatment were examined to compare their corrosion behaviors. All results indicate that corrosion resistance was enhanced, making the treatment process highly promising.

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