Corrosion Behavior of 18-8 Stainless Steels in Hot Concentrated Caustic Soda Solutions under Heat-Transfer Conditions

CORROSION ◽  
1985 ◽  
Vol 41 (12) ◽  
pp. 720-727 ◽  
Author(s):  
M. Yasuda ◽  
S. Tokunaga ◽  
T. Taga ◽  
F. Hine
Keyword(s):  
Heat Transfer ◽  
Caustic Soda ◽  
Corrosion Behavior ◽  
Stainless Steels ◽  
Detrimental Effect ◽  
Heated Surface ◽  
Caustic Solution ◽  
General Corrosion ◽  
Aisi 304 ◽  
Aisi 316

Abstract The corrosion behavior of AISI 304 and 316 stainless steels (SSs) in hot concentrated caustic soda solutions was investigated under heat-transfer conditions. The corrosion potential of the specimens was located in the active region; thus, the alloys were attacked in the form of general corrosion, depending on the heat-transfer conditions. AISI 316 was more susceptible than AISI 304. Such corrosion behavior is attributed to the failure of the passive film on the heated surface, caused by concentration of caustic solution next to the metal surface and erosion by gas bubbles. A molybdenum-free alloy, AISI 305J1, was tested under the same conditions as AISI 316 to clarify the detrimental effect of Mo on austenitic SS corrosion in hot concentrated NaOH. Intergranular corrosion was occasionally found when the potential was located in the passive region, depending on test conditions and heat treatment of the specimens.

scholarly journals Breakdown and Evolution of the Protective Oxide Scales of AISI 304 and AISI 316 Stainless Steels under High-Temperature Oxidation

2011 ◽  
Vol 2011 ◽  
pp. 1-10 ◽  
Author(s):  
K. A. Habib ◽  
M. S. Damra ◽  
J. J. Saura ◽  
I. Cervera ◽  
J. Bellés
Keyword(s):  
Stainless Steel ◽  
Stainless Steels ◽  
Breakdown Point ◽  
304 Stainless Steel ◽  
Aisi 304 Stainless Steel ◽  
Protective Oxide ◽  
Aisi 304 ◽  
316 Stainless Steel ◽  
Aisi 316 Stainless Steel ◽  
Aisi 316

The failure of the protective oxide scales of AISI 304 and AISI 316 stainless steels has been studied and compared at 1,000°C in synthetic air. First, the isothermal thermogravimetric curves of both stainless steels were plotted to determine the time needed to reach the breakdown point. The different resistance of each stainless steel was interpreted on the basis of the nature of the crystalline phases formed, the morphology, and the surface structure as well as the cross-section structure of the oxidation products. The weight gain of AISI 304 stainless steel was about 8 times greater than that of AISI 316 stainless steel, and AISI 316 stainless steel reached the breakdown point about 40 times more slowly than AISI 304 stainless steel. In both stainless steels, reaching the breakdown point meant the loss of the protective oxide scale of Cr2O3, but whereas in AISI 304 stainless steel the Cr2O3scale totally disappeared and exclusively Fe2O3was formed, in AISI 316 stainless steel some Cr2O3persisted and Fe3O4was mainly formed, which means that AISI 316 stainless steel is more resistant to oxidation after the breakdown.

scholarly journals Aluminum coating by fluidized bed chemical vapor deposition on austenitic stainless steels AISI 304 and AISI 316

DYNA ◽  
2015 ◽  
Vol 82 (189) ◽  
pp. 22-29
Author(s):  
Jose Luddey Marulanda-Arevalo ◽  
Saul Castañeda-Quintana ◽  
Francisco Javier Perez-Trujillo
Keyword(s):  
Chemical Vapor Deposition ◽  
Fluidized Bed ◽  
Stainless Steels ◽  
Vapor Deposition ◽  
Chemical Vapor ◽  
Austenitic Stainless Steels ◽  
Aluminum Coating ◽  
Aisi 304 ◽  
Aisi 316

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.

scholarly journals Influence of free energy on the attachment of Salmonella Enteritidis and Listeria monocytogenes on stainless steels AISI 304 and AISI 316

LWT ◽  
2016 ◽  
Vol 69 ◽  
pp. 131-138 ◽  
Author(s):  
Letícia Sopeña Casarin ◽  
Fabrício de Oliveira Casarin ◽  
Adriano Brandelli ◽  
Júnia Novello ◽  
Sukarno Olavo Ferreira ◽  
...  
Keyword(s):  
Free Energy ◽  
Listeria Monocytogenes ◽  
Stainless Steels ◽  
Salmonella Enteritidis ◽  
Aisi 304 ◽  
Aisi 316

Thiosulfate Corrosion in Paper-Machine White Water

CORROSION ◽  
1985 ◽  
Vol 41 (10) ◽  
pp. 587-591 ◽  
Author(s):  
A. Garner
Keyword(s):  
Stainless Steels ◽  
Paper Machine ◽  
Aisi 304 ◽  
Molar Ratios ◽  
White Water ◽  
Aisi 316

Abstract Potentiostatic, potentiodynamic, and immersion tests were conducted on a range of alloys used in paper-machine service. It was found that thiosulfate contamination of white water can cause pitting in AISI 304 and CA-15 stainless steels (SS), and, by comparison, salts such as NaCl, Na2SO, and Al2(SO4)3 are much less corrosive. For sensitized AISI 304, thiosulfate levels in the range of 3 to 75 ppm cause pitting, 5 to 20 ppm S2O3= being particularly aggressive. Thiosulfate pitting occurred in the absence of chlorides when sulfate was present at SO4=:S2O3= molar ratios from 1.6 to 58. Compared to AISI 304, significantly greater resistance to thiosulfate pitting was found in AISI 316 and 317 L, Ferralium 255, and cast duplex SS, KCR-A171 and Alloy 75.

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