Cathodic modification of stainless steels with ruthenium: a review of recent advances in making the cheaper option cheaper

Abstract

AbstractCorrosion resistance of stainless steels is significantly compromised in oxygen-deficient environments, leading to limited service life as well as unsatisfactory performance of the structures made of these alloys. Cathodic modification with ruthenium has been demonstrated to remarkably improve the corrosion resistance of stainless steels in reducing acidic media, even in the presence of an abrasive suspension. Although ruthenium is several times cheaper than other platinum group metals (PGMs), alloying with ruthenium remains prohibitively more expensive than alloying with conventional, although less effective, metals. A number of strategies have been explored to reduce the amount of ruthenium required to cathodically modify stainless steels in a bid to make this cheaper option much cheaper and thus increase the cost-benefits of using these alloys. Some of the strategies include partially substituting ruthenium with cheaper metals, as well as introducing the PGM as a surface alloy.