Browsing by Author "Costin, W"

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    The effect of the crystallographic texture on intergranular stress corrosion crack paths
    (Elsevier, 2014-11) Lavigne, O; Gamboa, E; Luzin, V; Law, M; Giuliani, M; Costin, W
    Intergranular stress corrosion cracking (IGSCC) crack paths usually travel perpendicular to the applied load direction. Some instances of crack paths propagating in directions away from the perpendicular have been observed in low carbon steels. This study shows that the crystallographic texture is a critical factor that drives the IGSCC crack path. Residual shear strain induced by shear texture (induced by rolling processes) explains the inclination of the cracks at a certain depth and the continuous propagation of the cracks along the transverse directions. The residual strains coming from the manufacturing processes determine the crack propagation paths. © 2014, Elsevier B.V.
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    Microstructural and mechanical factors influencing high pH stress corrosion cracking susceptibility of low carbon line pipe steel
    (Elsevier, 2014-10) Lavigne, O; Gamboa, E; Costin, W; Law, M; Luzin, V; Linton, V
    Several adjacent gas pipe sections were obtained from the field. These pipe sections had nominally identical manufacturing, construction, coating and operational conditions. Some sections were unaffected by stress corrosion cracking (SCC), whereas surrounding sections were affected by SCC. Slight differences in mechanical and microstructural properties were found between the two types of section. Residual stress/strain and hardness close to the outer surface of the pipes and high angle boundary fraction values were lower for the non-cracked pipe sections. Predominant 〈1 1 0〉//ND texture was also found at the outer surface of the non-cracked pipe sections. These characteristics lead to a lower crack growth rate in laboratory SCC experiments. These features being mainly a result of the line pipe steel manufacturing operations, appropriate metallurgical processes leading to low residual stress (6.2%YS), relatively low fraction of high angle boundaries (about 0.75) and predominant {1 1 0}〈1 1 0〉 texture in the material (or in the near surface) are expected to greatly improve the stress corrosion cracking resistance of line pipe steels on the field. © 2014, Elsevier Ltd.