Change search
ReferencesLink to record
Permanent link

Direct link
Hydrogen-assisted stress corrosion cracking of high strength steel
KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering.
2011 (English)Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
Abstract [en]

In this work, Slow Strain Rate Test (SSRT) testing, Light Optical Microscopy (LOM) and Scanning Electron Microscopy (SEM) were used to study the effect of microstructure, corrosive environments and cathodic polarisation on stress corrosion cracking (SCC) of two grades of high strength steels, Type A and Type B. Type A is manufactured by quench and tempered (Q&T) method. Type B, a normalize steel was used as reference. This study also supports electrochemical polarisation resistance method as an effective testing technique for measuring the uniform corrosion rate. SSRT samples were chosen from base metal, weld metal and Heat Affected Zone (HAZ). SSRT tests were performed at room temperature under Open Circuit Potential (OCP) and cathodic polarisation using 4 mA/cm2 in 1 wt% and 3.5 wt% NaCl solutions. From the obtained corrosion rate measurements performed in 1 wt% and 3.5 wt% NaCl solutions it was observed that increased chloride concentration and dissolved oxygen content enhanced the uniform corrosion for all tested materials. Moreover, the obtained results from SSRT tests demonstrate that both Q&T and normalized steels were not susceptible to SCC in certain strain rate (1×10-6 s-1) in 1 wt% and 3.5 wt% NaCl solutions under OCP condition. It was confirmed by a ductile fracture mode and high reduction in area. The weld metal of Type A with acicular ferrite (AF), pro-eutectoid (PF) and bainite microstructure showed higher susceptibility to hydrogen assisted stress corrosion cracking compared to base metal and HAZ. In addition, typical brittle intergranular cracking with small reduction in area was observed on the fracture surface of the Type A due to hydrogen charging.

Place, publisher, year, edition, pages
2011. , 65 p.
Keyword [en]
Hydrogen assisted stress corrosion cracking, Hydrogen embrittlement, High strength steel, Slow Strain Rate Test
National Category
Materials Engineering
URN: urn:nbn:se:kth:diva-103265OAI: diva2:559358
Subject / course
Corrosion Science
Educational program
Master of Science - Materials Science and Engineering
2011-08-24, Swerea KIMAB, Stockholm, 08:08 (English)
Available from: 2012-10-09 Created: 2012-10-09 Last updated: 2012-10-09Bibliographically approved

Open Access in DiVA

fulltext(6493 kB)795 downloads
File information
File name FULLTEXT01.pdfFile size 6493 kBChecksum SHA-512
Type fulltextMimetype application/pdf

By organisation
Materials Science and Engineering
Materials Engineering

Search outside of DiVA

GoogleGoogle Scholar
Total: 795 downloads
The number of downloads is the sum of all downloads of full texts. It may include eg previous versions that are now no longer available

Total: 337 hits
ReferencesLink to record
Permanent link

Direct link