Factors Affecting Housing and Utilities Pipe Corrosion Resistance

Modification of Non-Metallic Inclusions in Oil-Pipeline Steels by Ca-Treatment

“…It is known that the main cause of high corrosion rates of oilfield pipelines is contaminations of steel by certain harmful non-metallic inclusions, which are precipitated in steel during the ladle treatment and casting process. Such inclusions are called corrosion-active non-metallic inclusions [10,11]. However, these non-metallic inclusions in modern steels have usually a complex chemical composition, where often the influence of the composition on the corrosion is not fully known.…”

“…However, these non-metallic inclusions in modern steels have usually a complex chemical composition, where often the influence of the composition on the corrosion is not fully known. Previous authors have reported negative effects on the corrosion resistance of oil-field pipeline steels due to two types of non-metallic inclusions [10,11]. The first type is non-metallic inclusions based on calcium aluminates, which sometimes contain magnesium and silicon oxides.…”

Confirmation of Hydrogen Embrittlement Mechanism for Stress Corrosion Cracking of Gas Main Lines

“…Being aggressive (from the point of view of SCC) in relation to this class of materials, the latter are inactive in relation to other (sometimes close in structure and chemical composition) steels. Thus, SCC can develop in specific metal-medium systems [6][7][8][9].…”

“…If the process of microdamage accumulation takes place at the top of the stress concentrator, at a certain level of the latter the surface layer, attenuated by metal microdamage with a passivation film, might get destroyed and an unprotected metal surface might be formed. On the formed surface, the process of microdamage accumulation will resume, after which the weakened surface layer will be destroyed, and thus further growth of the generated stresscorrosion crack will occur [7,9,10,12,13].…”