Server maintenance is scheduled for Saturday, December 21st between 6am-10am CST.

During that time, parts of our website will be affected until maintenance is completed. Thank you for your patience.

Search
Filters
Close

51315-5439-Corrosion and Corrosion Product Release Behavior of Co-Cr-W-C Weld Deposit

Product Number: 51315-5439-SG
ISBN: 5439 2015 CP
Author: Michael LeClair
Publication Date: 2015
$0.00
$0.00
$0.00
The corrosion behavior of Co-Cr-W-C weld deposit (MIL-R-17131A Type R-Co-Cr-A welding rod) was testing in deaerated pH adjusted water at 500 F for up to 10000 hours and subsequently analyzed by X-Ray Diffraction Auger Electron Spectroscopy and Electron Spectroscopy for Chemical Analysis to determine oxide composition and Scanning Electron Microscopy and Focused Ion Beam excavation to measure oxide thickness. The resultant weld deposit corrosion rate was three times higher than that of the analogous wrought material. The primary oxide phase composition of all surfaces was CoCr2O4; some corrosion films had a high-Co phase likely CoFe2O4 or CoO on their outermost surface. Thin corrosion films were found on the specimen surfaces thinner over the Cr-rich carbide phase than the Co-Cr-W metal matrix except where the carbide boundaries intersect the surface. Where this occurs corrosion penetrates down and around the carbides where the adjacent metal matrix regions are likely depleted in Cr and more susceptible to attack. These sub-surface corroded areas may have been excluded in other evaluations at shorter exposures thus understating this material's long-term corrosion rate. As a post-weld stress relief heat treatment applied to some specimens resulted in more carbides it also resulted in higher corrosion rates.Key words: Corrosion cobalt alloy weld oxide carbide
The corrosion behavior of Co-Cr-W-C weld deposit (MIL-R-17131A Type R-Co-Cr-A welding rod) was testing in deaerated pH adjusted water at 500 F for up to 10000 hours and subsequently analyzed by X-Ray Diffraction Auger Electron Spectroscopy and Electron Spectroscopy for Chemical Analysis to determine oxide composition and Scanning Electron Microscopy and Focused Ion Beam excavation to measure oxide thickness. The resultant weld deposit corrosion rate was three times higher than that of the analogous wrought material. The primary oxide phase composition of all surfaces was CoCr2O4; some corrosion films had a high-Co phase likely CoFe2O4 or CoO on their outermost surface. Thin corrosion films were found on the specimen surfaces thinner over the Cr-rich carbide phase than the Co-Cr-W metal matrix except where the carbide boundaries intersect the surface. Where this occurs corrosion penetrates down and around the carbides where the adjacent metal matrix regions are likely depleted in Cr and more susceptible to attack. These sub-surface corroded areas may have been excluded in other evaluations at shorter exposures thus understating this material's long-term corrosion rate. As a post-weld stress relief heat treatment applied to some specimens resulted in more carbides it also resulted in higher corrosion rates.Key words: Corrosion cobalt alloy weld oxide carbide
Product tags
Also Purchased
Picture for Corrosion of Ni-based Alloys and Stainless Steels in Mixed Acids and Salts—Experimental and Modeling
Available for download

51315-5430-Corrosion of Ni-based Alloys and Stainless Steels in Mixed Acids and Salts—Experimental and Modeling Results

Product Number: 51315-5430-SG
ISBN: 5430 2015 CP
Author: Narasi Sridhar
Publication Date: 2015
$0.00
Picture for Corrosion of Brackish Water Systems Used for In Situ Thermal Operations
Available for download

51315-5444-Corrosion of Brackish Water Systems Used for In Situ Thermal Operations

Product Number: 51315-5444-SG
ISBN: 5444 2015 CP
Author: Tesfaalem Haile
Publication Date: 2015
$0.00