Stress corrosion cracking fracture mechanisms in rock bolts

dc.contributor.authorGamboa, E.
dc.contributor.authorAtrens, A.
dc.date.issued2003
dc.descriptionThe original publication is available at www.springerlink.com
dc.description.abstractRock bolts have failed by Stress Corrosion Cracking (SCC). This paper presents a detailed examination of the fracture surfaces in an attempt to understand the SCC fracture mechanism. The SCC fracture surfaces, studied using Scanning Electron Microscopy (SEM), contained the following different surfaces: Tearing Topography Surface (TTS), Corrugated Irregular Surface (CIS) and Micro Void Coalescence (MVC). TTS was characterised by a ridge pattern independent of the pearlite microstructure, but having a spacing only slightly coarser than the pearlite spacing. CIS was characterised as porous irregular corrugated surfaces joined by rough slopes. MVC found in the studied rock bolts was different to that in samples failed in a pure ductile manner. The MVC observed in rock bolts was more flat and regular than the pure MVC, being attributed to hydrogen embrittling the ductile material near the crack tip. The interface between the different fracture surfaces revealed no evidence of a third mechanism involved in the transition between fracture mechanisms. The microstructure had no effect on the diffusion of hydrogen nor on the fracture mechanisms. The following SCC mechanism is consistent with the fracture surfaces. Hydrogen diffused into the material, reaching a critical concentration level. The thus embrittled material allowed a crack to propagate through the brittle region. The crack was arrested once it propagated outside the brittle region. Once the new crack was formed, corrosion reactions started producing hydrogen that diffused into the material once again.
dc.description.statementofresponsibilityE. Gamboa and A. Atrens
dc.identifier.citationJournal of Materials Science, 2003; 38(18):3813-3829
dc.identifier.doi10.1023/A:1025996620197
dc.identifier.issn0022-2461
dc.identifier.issn1573-4803
dc.identifier.urihttp://hdl.handle.net/2440/43389
dc.language.isoen
dc.publisherKluwer Academic Publ
dc.source.urihttps://doi.org/10.1023/a:1025996620197
dc.titleStress corrosion cracking fracture mechanisms in rock bolts
dc.typeJournal article
pubs.publication-statusPublished

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