Menu
Search
Filters
Close
Menu

Laboratory experiments vs Field experience – Localized corrosion performance of lean duplex stainless steel UNS S32202 in municipal wastewater treatment plants

Picture for Laboratory experiments vs Field experience – Localized corrosion performance of lean duplex stainless steel UNS S32202 in municipal wastewater treatment plants
Available for download

Thanks to their good corrosion resistance and ease to shape and weld, austenitic stainless steel grades (e.g. UNS S31603) are used as standard materials for the construction of municipal wastewater treatment plants (WWTP). The main factors influencing the corrosiveness of the fluids in WWTP are halides concentration (more specifically chlorides), H2S content, low pH, temperature and their combined effects.

In municipal wastewater streams, chloride content, known to be one of the critical agents affecting the stability of protective passive layers for stainless steels2, is usually around 50-200 mg/L and in this content range does not present major issues for the austenitic grade.

Product Number: 51323-19159-SG
Author: Audrey Allion, Charles David, Benoit Emo, Nicolas Larché
Publication Date: 2023
$0.00
$20.00
$20.00

Thanks to their good corrosion resistance and ease to shape and weld, austenitic stainless steels (e.g. UNS S31603) are used as standard materials for the construction of urban wastewater treatment plants (WWTP). The main factors influencing the corrosiveness of the fluids in WWTP are halide concentration (more specifically chlorides), H2S content, low pH, temperature and their combined effects.


The present paper deals with the localized corrosion performance of lean duplex UNS S32202 in solutions or in atmosphere simulating pre-treatment unit environment. It is compared to the austenitic stainless steel UNS S31603 and the higher alloyed duplex stainless steel UNS S32205. Crevice corrosion testing was performed using crevice formers defined in ISO<xref rid="fn1-c2023-19159" ref-type="fn">(1)</xref> 18070:2015. The effect of welding was also investigated, with and without post-welding pickling. Both laboratory screen tests and field exposures in urban wastewater treatment plants were performed. Exposures of samples in field municipal wastewater plants were conducted for 1 year in a low chloride content unit (Brussels, Belgium) and in a high chloride content unit (Cap Sicié, France).


The results give an overview of corrosion properties according to temperature, chloride and H2S contents enabling to choose properly the most appropriate stainless steel grade for urban wastewater treatment plants. The results from field exposures (1 year) showed good agreement with laboratory results in simulated environments. This study confirms that lean duplex grade UNS S32202 can be used as an alternative to UNS S31603 in immersion and atmospheric exposure conditions for those two grades when exposed to splash zones (combination of H2S and chloride contamination): H2S (<10 ppm) and chloride (<200 ppm). For higher contaminations (e.g. H2S around 100 ppm and chloride content around 1000 ppm) the duplex grade UNS S32205 should be preferred. Whatever the tested condition and alloy, post-weld pickling shall never be avoided.

Thanks to their good corrosion resistance and ease to shape and weld, austenitic stainless steels (e.g. UNS S31603) are used as standard materials for the construction of urban wastewater treatment plants (WWTP). The main factors influencing the corrosiveness of the fluids in WWTP are halide concentration (more specifically chlorides), H2S content, low pH, temperature and their combined effects.


The present paper deals with the localized corrosion performance of lean duplex UNS S32202 in solutions or in atmosphere simulating pre-treatment unit environment. It is compared to the austenitic stainless steel UNS S31603 and the higher alloyed duplex stainless steel UNS S32205. Crevice corrosion testing was performed using crevice formers defined in ISO<xref rid="fn1-c2023-19159" ref-type="fn">(1)</xref> 18070:2015. The effect of welding was also investigated, with and without post-welding pickling. Both laboratory screen tests and field exposures in urban wastewater treatment plants were performed. Exposures of samples in field municipal wastewater plants were conducted for 1 year in a low chloride content unit (Brussels, Belgium) and in a high chloride content unit (Cap Sicié, France).


The results give an overview of corrosion properties according to temperature, chloride and H2S contents enabling to choose properly the most appropriate stainless steel grade for urban wastewater treatment plants. The results from field exposures (1 year) showed good agreement with laboratory results in simulated environments. This study confirms that lean duplex grade UNS S32202 can be used as an alternative to UNS S31603 in immersion and atmospheric exposure conditions for those two grades when exposed to splash zones (combination of H2S and chloride contamination): H2S (<10 ppm) and chloride (<200 ppm). For higher contaminations (e.g. H2S around 100 ppm and chloride content around 1000 ppm) the duplex grade UNS S32205 should be preferred. Whatever the tested condition and alloy, post-weld pickling shall never be avoided.

Product tags
Also Purchased
Picture for Investigation On The Localized Corrosion Performance Of Lean Duplex Stainless Steels In Urban Wastewater Treatment Plants
Available for download

Investigation On The Localized Corrosion Performance Of Lean Duplex Stainless Steels In Urban Wastewater Treatment Plants

Product Number: 51322-17756-SG
Author: Audrey Allion, Nicolas Larché, Dominique Thierry, Benoît Emo, Elisabeth Johansson
Publication Date: 2022
$20.00

Wastewater coming from both municipal and industrial activities present corrosive properties toward metals and can in certain cases exceed the tolerances of the most often used stainless steels such as 304L and 316L, thus resulting in the need of superior alloys. The main factors influencing the corrosiveness of the fluids in wastewater treatment plants are high concentration of halides (more specifically chlorides), H2S, low pH, temperature and their combined action. Corrosiveness of incoming fluids at a municipal wastewater treatment finds its roots in the municipal collection network.
Picture for Lightweight Sol-Gel Coating to Mitigate Galvanic Corrosion
Available for download

Lightweight Sol-Gel Coating to Mitigate Galvanic Corrosion

Product Number: 51323-18758-SG
Author: Adam Goff, Charles Sprinkle, Ben Pinkston, Fernando Farelas, Ariel Farelas
Publication Date: 2023
$20.00

Aircraft reliability and maintainability are critical to their availability and operation. One of the biggest threats to aircraft availability is corrosion of aircraft systems. The annual cost of corrosion for Air Force aviation and missiles is estimated to be $5.67B dollars, or 23.6% of total maintenance costs for this equipment, and 2.1 million non-available hours. It is estimated that for defense acquisition programs 60 – 80% of the total life cycle cost is associated with the operation and support (O&S) phase.
Picture for Localized Corrosion of High-Grade Stainless Steels in Chlorinated Seawater
Available for download

Localized Corrosion of High-Grade Stainless Steels in Chlorinated Seawater

Product Number: 51323-18911-SG
Author: Nicolas Larché, Charles Leballeur, Sandra Le Manchet, Wenle He
Publication Date: 2023
$20.00

In natural seawater, microorganisms can fix, grow and develop on practically any surface, including stainless steels, which may cause industrial issues such as microbial induced corrosion, loss of heat transfer efficiency, or undesired colonization from macro-fouling. In particular, the presence of a biofilm on passive alloys such as stainless steels or nickel-based alloys can strongly enhance the cathodic reactions such as reduction of dissolved oxygen, and shift the open-circuit potential (OCP) to the noble direction.This results in an increase in OCP, also called cathodic depolarization or biofilm-induced ennoblement, and affects the risk of localized corrosion, since the critical pitting or crevice potential can be exceeded.
Categories
Industry
Recently viewed
Popular tags
View all

Association for Materials Protection and Performance

© AMPP All Rights Reserved.
Membership Terms of Content Use
Contact Customer Support