Menu
Search
Filters
Close
Menu

Save 20% on select titles with code HIDDEN24 - Shop The Sale Now

51316-7308-Effect of Tungsten on Pitting and Crevice Corrosion of Type 25Cr Super Duplex Stainless Steel

Picture for Effect of Tungsten on Pitting and Crevice Corrosion of Type 25Cr Super Duplex Stainless Steel
Available for download

To examine the effect of Tungsten (W) on localized corrosion of 2 superduplex stainless steels (SDSS)- high & low-W. Both plain samples (pitting corrosion) and samples with artificial crevices (crevice corrosion) were exposed. Tests in 3.50-wt% NaCl solution or natural seawater. T= 30 to 90°C.

Product Number: 51316-7308-SG
ISBN: 7308 2016 CP
Author: Roy Johnsen
Publication Date: 2016
Industry: Oil and Gas Production
$0.00
$20.00
$20.00

The oil and gas industry frequently uses type 25Cr super duplex stainless steels (SDSS) both for seawater applications and for pipes and components exposed to hydrocarbon environments topside and subsea. During the last years, the effect of tungsten on pitting and crevice corrosion resistance has been debated among corrosion experts. In particular, some authors claim that W has a strong synergistic effect with molybdenum when added above a certain threshold value. In the solution annealed condition, tungsten-containing SDSS have been claimed to offer corrosion resistance on a par with higher-grade steels such as type 6Mo (UNS S31254) super austenitic stainless steel grades.

The objective of this investigation was to examine the effect of W on localized corrosion of two SDSS: a high-W (UNS S39274) and a low-W (mod. UNS S32750) grade. Both plain samples (pitting corrosion) and samples with artificial crevices (crevice corrosion) were exposed. Tests were conducted in a 3.50-wt% NaCl solution or natural seawater with temperature ranging from 30°C to 90°C. Cyclic Potentiodynamic polarization scans according to ASTM G-61, critical pitting temperature tests according to ASTM G-150, and long-term seawater open circuit potential exposures of creviced samples were conducted.

The outcome of the testing showed that W addition has a positive effect on both pitting and crevice corrosion resistance. We propose a new parametric definition of Pitting Resistant Equivalent.

Keywords: downloadable, super duplex stainless steels, seawater, critical pitting temperature, critical crevice temperature, cyclic potentiodynamic testing

The oil and gas industry frequently uses type 25Cr super duplex stainless steels (SDSS) both for seawater applications and for pipes and components exposed to hydrocarbon environments topside and subsea. During the last years, the effect of tungsten on pitting and crevice corrosion resistance has been debated among corrosion experts. In particular, some authors claim that W has a strong synergistic effect with molybdenum when added above a certain threshold value. In the solution annealed condition, tungsten-containing SDSS have been claimed to offer corrosion resistance on a par with higher-grade steels such as type 6Mo (UNS S31254) super austenitic stainless steel grades.

The objective of this investigation was to examine the effect of W on localized corrosion of two SDSS: a high-W (UNS S39274) and a low-W (mod. UNS S32750) grade. Both plain samples (pitting corrosion) and samples with artificial crevices (crevice corrosion) were exposed. Tests were conducted in a 3.50-wt% NaCl solution or natural seawater with temperature ranging from 30°C to 90°C. Cyclic Potentiodynamic polarization scans according to ASTM G-61, critical pitting temperature tests according to ASTM G-150, and long-term seawater open circuit potential exposures of creviced samples were conducted.

The outcome of the testing showed that W addition has a positive effect on both pitting and crevice corrosion resistance. We propose a new parametric definition of Pitting Resistant Equivalent.

Keywords: downloadable, super duplex stainless steels, seawater, critical pitting temperature, critical crevice temperature, cyclic potentiodynamic testing

Product tags
Also Purchased
Picture for 11255 Pitting Corrosion Mechanisms of Lean Duplex
Available for download

11255 Pitting Corrosion Mechanisms of Lean Duplex, Duplex and Super Duplex Stainless Steels in Chloride Solutions

Product Number: 51300-11255-SG
ISBN: 2011 11255 CP
Author: J. Saithala, J. Atkinson, H Ubhi, A. Patil
Publication Date: 2011
$20.00
Picture for 09194 Evaluation of Crevice Corrosion Resistance of Duplex and Super Duplex Stainless Steels for Sea
Available for download

09194 Evaluation of Crevice Corrosion Resistance of Duplex and Super Duplex Stainless Steels for Seawater Pumps

Product Number: 51300-09194-SG
ISBN: 09194 2009 CP
Author: Hiroshi Yakuwa, Katsuhiro Mitsuhashi, Kenichi Sugiyama and Matsuho Miyasaka
Publication Date: 2009
$20.00

The crevice corrosion resistance of duplex and super duplex stainless steels used for seawater pumps was evaluated by comparing the to results tests conducted using actual seawater  with the behavior of the stainless steels in artificial seawater
Picture for Corrosion Management Of Assets Constructed In Super Duplex Stainless Steels (SDSS)
Available for download

51316-6982-Corrosion Management Of Assets Constructed In Super Duplex Stainless Steels (SDSS)

Product Number: 51316-6982-SG
ISBN: 6982 2016 CP
Author: Glenn Byrne
Publication Date: 2016
$20.00

Based on alloy development and manufacturer independent supply experience of super duplex steel over a 30 year period the paper considers some of the less well known but recurring problems and the methods used to ameliorate them.
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