Menu
Search
Filters
Close
Menu

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

Environmentally Assisted Cracking Evaluation of UNS N06686 Using Constant Extension Rate Testing

Picture for 11296 Environmentally Assisted Cracking Evaluation of UNS N06686
Available for download
Product Number: 51300-11296-SG
ISBN: 2011 11296 CP
Author: Michelle G. Koul and Peggy S. LeGrand
Publication Date: 2011
$0.00
$20.00
$20.00
Constant, slow extension rate tests in air and ASTM D1141 seawater were conducted on two cold worked bars of Grade 2 IN686 (UNS N06686, 125 min. yield strength) where the cold work was imparted using two different methods: conventional drawing and rotary forging. Baseline tests were also conducted on Alloy K-500 (UNS N05500), which is a marine grade material currently in use. Specimens were cathodically polarized to simulate catholic protection conditions and evaluate the alloys’ resistance to hydrogen-assisted EAC (HEAC). Ductility measurements using elongation at fracture and reduction in area were used to quantitatively evaluate the HEAC susceptibility. In addition, qualitative fractographic assessments to identify EAC fracture modes were conducted using optical and scanning electron microscopy. The strength and fracture morphology was found to vary with the method of cold working employed. Susceptibility to HEAC was indicated for smooth specimens of IN686 at -1.0 VSCE<.sub> and 9x10-7 in/sec elongation rate via test data and the presence of secondary cracking. IN686 ductility losses were 25% at most, whereas Alloy K-500 measured a ductility loss of more than 60% under the same conditions. The measured effect of a thread-like notch was to reduce the elongation at fracture of IN686 to less than 10% for all conditions, and exacerbate the less ductile fracture modes that were observed.

Key words: environmentally assisted cracking, hydrogen embrittlement, nickel alloys, cathodic protection, marine corrosion
Constant, slow extension rate tests in air and ASTM D1141 seawater were conducted on two cold worked bars of Grade 2 IN686 (UNS N06686, 125 min. yield strength) where the cold work was imparted using two different methods: conventional drawing and rotary forging. Baseline tests were also conducted on Alloy K-500 (UNS N05500), which is a marine grade material currently in use. Specimens were cathodically polarized to simulate catholic protection conditions and evaluate the alloys’ resistance to hydrogen-assisted EAC (HEAC). Ductility measurements using elongation at fracture and reduction in area were used to quantitatively evaluate the HEAC susceptibility. In addition, qualitative fractographic assessments to identify EAC fracture modes were conducted using optical and scanning electron microscopy. The strength and fracture morphology was found to vary with the method of cold working employed. Susceptibility to HEAC was indicated for smooth specimens of IN686 at -1.0 VSCE<.sub> and 9x10-7 in/sec elongation rate via test data and the presence of secondary cracking. IN686 ductility losses were 25% at most, whereas Alloy K-500 measured a ductility loss of more than 60% under the same conditions. The measured effect of a thread-like notch was to reduce the elongation at fracture of IN686 to less than 10% for all conditions, and exacerbate the less ductile fracture modes that were observed.

Key words: environmentally assisted cracking, hydrogen embrittlement, nickel alloys, cathodic protection, marine corrosion
Product tags
Also Purchased
Picture for 11354 Monitoring the Corrosion of Copper-Nickel-Chromium Castings
Available for download

Monitoring the Corrosion of Copper-Nickel-Chromium Castings Using Electrochemical Frequency Modulation

Product Number: 51300-11354-SG
Author: Derek R. Lenard, Yueping Wang and Bradley A. Noren
Publication Date: 2011
$20.00
Picture for 11129 Integration of External Corrosion Direct Assessment
Available for download

Integration of External Corrosion Direct Assessment with Integrity Management Software Application

Product Number: 51300-11129-SG
ISBN: 2011 11129 CP
Author: Lyle Welsh
Publication Date: 2011
$20.00
Picture for 11294 Susceptibility of Hydrogen Induced Stress Cracking of Duplex SS at Elevated Temperature
Available for download

11294 Susceptibility of Hydrogen Induced Stress Cracking of Duplex Stainless Steel at Elevated Temperature

Product Number: 51300-11294-SG
ISBN: 2011 11294 CP
Author: Roy Johnson, Bard Nyhus, and Ole Edvard Kongstein
Publication Date: 2011
$20.00

Experience has shown that stainless steels can suffer from Hydrogen Induced Stress Cracking (HISC) under cathodic protection in seawater.  This paper presents results from a test program examining the HISC susceptibility of 25% Cr super duplex stainless steel (UNS S32750) at temperatures up to 1500C.
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