The corrosion mechanism of 1Cr18Ni9Ti alloy used for an underwater craft component. Issue 3 (5th May 2015)

• Record Type: Journal Article
• Authors: Cathy Liu, Dr; Peng, Zhiling; Zhao, Heming
• Is Part Of: Anti-corrosion methods and materials. Volume 62:Issue 3(2015)
• Page Start: 156
• Page End: 162
• Publication Date: 2015-05-05
• Subjects: Corrosion and anti-corrosives -- Periodicals; 620.11223
• DOI: 10.1108/ACMM-01-2015-1492
• Languages: English
• ISSNs: 0003-5599

Abstract

<abstract> <title> <x content-type="archive" xml:space="preserve">Abstract</x> </title> <sec> <title content-type="abstract-heading">Purpose</title> <p> – An engine component made from 1Cr18Ni9Ti alloy to be used underwater was the subject of the present research investigation. </p> </sec> <sec> <title content-type="abstract-heading">Design/methodology/approach</title> <p> – A stereomicroscope, a metallurgical microscope, a microhardness tester and an electron energy dispersion spectroscope were used to observe cross-sections of the alloy's microstructure at different locations, as well as its overall corrosion behavior. </p> </sec> <sec> <title content-type="abstract-heading">Findings</title> <p> – The corrosion of the 1Cr18Ni9Ti alloy, attributed to welding, cold processing and plastic deformation processes, was investigated together with an analysis of the chemical composition of the corrosion products and microsclerometry of the cross-sections. It was revealed that defects such as shrinkage cavities and porosity, often were observed to occur in the welding fusion zone. During cold processing treatments, work hardening was induced in the surface layer. Corrosion products consisted of oxides, chlorides and sulfides, with oxides as the dominant component. The high chromium content of d-ferrite had resulted in chromium depletion in nearby phase boundaries, which had led to oxidation and corrosion at these boundaries. As the electrode potential of d-ferrite is different to that of austenite, it is possible for a galvanic couple to develop between the two phases, leading to differential rates of corrosion attack. </p> </sec> <sec> <title content-type="abstract-heading">Originality/value</title> <p> – Methods are proposed to improve corrosion resistance by improving the quality of the surface overlaying processes and by adopting special surface treatment techniques.</p> </sec> </abstract>