scholarly journals Quantitative Nanoscale 3D Imaging of Intergranular Corrosion of 304 Stainless Steel Using Hard X-Ray Nanoprobe

2019 ◽  
Vol 166 (11) ◽  
pp. C3320-C3325 ◽  
Author(s):  
Simerjeet K Gill ◽  
Mingyuan Ge ◽  
Hanfei Yan ◽  
Kotaro Sasaki ◽  
Zhixiu Liang ◽  
...  
Keyword(s):  
Stainless Steel ◽  
Intergranular Corrosion ◽  
3D Imaging ◽  
304 Stainless Steel ◽  
X Ray

scholarly journals X-ray Diffraction Investigation of Stainless Steel—Nitrogen Thin Films Deposited Using Reactive Sputter Deposition

Coatings ◽  
2020 ◽  
Vol 10 (10) ◽  
pp. 984
Author(s):  
Faisal I. Alresheedi ◽  
James E. Krzanowski
Keyword(s):  
Thin Films ◽  
Stainless Steel ◽  
Substrate Temperature ◽  
Peak Shift ◽  
304 Stainless Steel ◽  
Tetragonal Structure ◽  
X Ray Diffraction ◽  
X Ray ◽  
Area Detector ◽  
Calculated Parameter

An X-ray diffraction investigation was carried out on nitrogen-containing 304 stainless steel thin films deposited by reactive rf magnetron sputtering over a range of substrate temperature and bias levels. The resulting films contained between ~28 and 32 at.% nitrogen. X-ray analysis was carried out using both the standard Bragg-Brentano method as well as area-detector diffractometry analysis. The extent of the diffraction anomaly ((002) peak shift) was determined using a calculated parameter, denoted RB, which is based on the (111) and (002) peak positions. The normal value for RB for FCC-based structures is 0.75 but increases as the (002) peak is anomalously displaced closer to the (111) peak. In this study, the RB values for the deposited films were found to increase with substrate bias but decrease with substrate temperature (but still always >0.75). Using area detector diffractometry, we were able to measure d111/d002 values for similarly oriented grains within the films, and using these values calculate c/a ratios based on a tetragonal-structure model. These results allowed prediction of the (002)/(200) peak split for tetragonal structures. Despite predicting a reasonably accessible split (~0.6°–2.9°–2θ), no peak splitting observed, negating the tetragonal-structure hypothesis. Based on the effects of film bias/temperature on RB values, a defect-based hypothesis is more viable as an explanation for the diffraction anomaly.

Effect of Austenizing and Tempering Time on Corrosion Rate of Austenitic Stainless Steel in Oxalic Acid

2014 ◽  
Vol 980 ◽  
pp. 46-51
Author(s):  
Mohamed A. Gebril ◽  
M.S. Aldlemey ◽  
Farag I. Haider ◽  
Naji Ali
Keyword(s):  
Stainless Steel ◽  
Austenitic Stainless Steel ◽  
Corrosion Rate ◽  
Oxalic Acid ◽  
Intergranular Corrosion ◽  
Room Temperature ◽  
304 Stainless Steel ◽  
Tempering Temperature ◽  
Weight Losses ◽  
Tempering Time

The aim of this work is to study the effect of austenizing time, tempering process and tempering time on corrosion rate of austenitic stainless steel in oxalic acid. The samples of typical 304 stainless steel were heated to 1050°C for 10, 20 and 30 minutes and quenched to room temperature in water, then tempered at 250°C, 400°C and 600°C for 30, 60 minutes for each tempering time. These samples were then immersed in 0.1M of oxalic acid and then their weight losses were measured after 30 days. The result obtained show that corrosion rate of all austenitic stainless steel samples decreased with an increase austenizing time, this behaviour is due to more homogenously of austenite, and the corrosion rate will be increased with increase the tempering temperature and tempering time, this behaviour is due different phases at microstructure below 400°C, and above of 400 to 600°C the corrosion rate will be increased due to formation of carbides which are non-uniform distributed at the grain boundaries and causes intergranular corrosion.

Corrosion Behaviour of AISI 304 Stainless Steel with Solar Salt Heat Transfer Fluid

2014 ◽  
Vol 922 ◽  
pp. 13-17 ◽  
Author(s):  
Omar Ahmed ◽  
Le Zhou ◽  
Nahid Mohajeri ◽  
Yong Ho Sohn
Keyword(s):  
Heat Transfer ◽  
Stainless Steel ◽  
Iron Oxide ◽  
Corrosion Behavior ◽  
304 Stainless Steel ◽  
Salt Mixture ◽  
Aisi 304 Stainless Steel ◽  
Aisi 304 ◽  
Solar Salt ◽  
X Ray

In an effort to understand the compatibility between the heat transfer medium and the structural materials used in concentrated solar power plants, the corrosion behavior of AISI 304 stainless steel (18 wt.% Cr, 8 wt.% Ni) in a molten solar salt mixture (53 wt. % KNO3, 40 wt. % NaNO2,7 wt. % NaNO3) has been investigated. The 304 stainless steel coupon samples were fully immersed and isothermally exposed to solar salt at 530°C for 250, 500, and 750 hours in air. X-ray diffraction and scanning electron microscopy with X-ray energy-dispersive spectroscopy were employed to examine the extent of corrosion and identify the corrosion products. Oxides of iron were found to be the primary corrosion products in the presence of the molten alkali nitrates-nitrite salt mixture because of the dissolution of the protective chromium oxide (Cr2O3) scale formed on 304 stainless steel coupons. The corrosion scale was uniform in thickness and chromium-iron oxide was found near the AISI 304. This indicates that the scale formed, particularly on the upper layer with presence of sodium-iron-oxide is protective, and forms an effective barrier against penetration of fused solar salt. By extrapolation, annual corrosion rate is estimated to reach 0.784 mils per year. Corrosion behavior of AISI 304 stainless steel is discussed in terms of thermodynamics and reaction paths.

Operando Assessment of Galvanic Corrosion Between Al-Zn-Mg-Cu Alloy and a Stainless Steel Fastener Using X-ray Tomography

CORROSION ◽  
10.5006/2561 ◽  
2017 ◽  
Vol 74 (1) ◽  
pp. 5-23 ◽  
Author(s):  
Veronica N. Rafla ◽  
Andrew D. King ◽  
Sarah Glanvill ◽  
Alison Davenport ◽  
John R. Scully
Keyword(s):  
Stainless Steel ◽  
Galvanic Corrosion ◽  
Steel Wire ◽  
304 Stainless Steel ◽  
Potential Range ◽  
Secondary Phases ◽  
X Ray ◽  
Faraday’S Law ◽  
Intermetallic Particles ◽  
Pure Cu

Operando x-ray tomography was used to study the galvanic corrosion between aluminum alloy 7050-T7451 and Type 304 stainless steel using a simulated fastener covered with droplets of either 4 M NaCl or 2 M MgCl2. The simulated rivet was an x-ray transparent cylindrical 1 mm pin with a 250 μm diameter rivet hole in the center. The rivet hole was embedded with a 500 μm, in length, stainless steel wire. The rivet hole formed an alkaline crevice between the stainless steel and AA7050-T7451 owing to the proximity of anodic and cathodic sites. The corrosion fissures followed an intragranular path and did not follow bands of intermetallic particles. The x-ray tomography indicated that multiple corrosion fissures propagated over the galvanic couple potential range at all depths examined suggesting the presence of multiple strong proximate cathodes. The volume loss was converted to anodic charge using Faraday’s Law. Cathodic reaction rate studies were conducted on Type 316 stainless steel, copper replated on AA7050, pure Cu, and other matrix secondary phases in simulated crevice environments to assess the ability of each to support fissure corrosion. The substrates for fast cathodic reactions capable of supporting the growth of these fissures were found to be the stainless steel fastener, copper replating on the AA7050-T7451 surface, and dealloyed S-phase. Moreover, removal of the stainless steel fastener stifled fissure growth. The damage morphology assessed with x-ray tomography was compared to laboratory-produced accelerated exposures, as well as field data, and were found to have similar morphologies.

Photocathode Protection Properties of TiO2/V2O5 Coating

2009 ◽  
Vol 79-82 ◽  
pp. 651-654 ◽  
Author(s):  
Min Jie Zhou ◽  
Li Zhong
Keyword(s):  
Stainless Steel ◽  
Steel Substrate ◽  
Sol Gel ◽  
304 Stainless Steel ◽  
X Ray Diffraction ◽  
X Ray ◽  
Uv Illumination ◽  
Type 304 ◽  
Type 304 Stainless Steel ◽  
Cathode Protection

Nano-sized TiO2/V2O5 bilayer coatings were prepared on type304 stainless steel substrate by sol-gel method and were characterized by scanning electron microscope (SEM), X-ray diffraction (XRD). The performance of photocathode protection of the coating was investigated by the electrochemical method. SEM results indicate that the coating surface is continuous, uniform and dense, XRD spectra show that the coating is of anatase TiO2 and V2O5. The experimental results demonstrate that type 304 stainless steel with the bilayer coating can maintain cathode protection for 6h in the dark after irradiation by UV illumination for 1 h.

Sign in / Sign up

Export Citation Format

Share Document