Anticorrosivity of Electroless Ni-P-TiO2 Nanoplatings against Hydrogen Peroxide Solution

The pollution regulator measurements have resulted replacement of chlorine/chlorine dioxide through hydrogen peroxides as bleaching chemicals specially in paper, dye and textile industries. Adaptation of changed chemicals, generally affects the corrosion aspects, suitability of existing plant metallurgy, materials of construction of equipment and environmental conditions. The surface platings besides non-sactrificial, recently have acted as an obstacle between steel substrates and corrosive environments. Accordingly, a long-term immersion and electrochemical corrosion tests were conducted on steels (MS, SS 316L) and electroless plated Ni-P and Ni-P-TiO2 nanomaterials in hydrogen peroxide solutions at pH 9.1 ± 0.1 and an E-pH was diagram drawn for H2O-H2O2 system alongside Shannon entropy values were calculated by MATLAB software and are used to understand the corrosivity of the peroxide media and protection mechanism of tested materials. On the basis of long-term immersion corrosion test, electrochemical corrosion tests, an H2O-H2O2 E-pH diagram, Shannon entropy values and cost to mechanical properties; the different tested materials may be graded in terms of their resistance against uniform/localized type corrosion for handling peroxide test media in following manner: Ni-P-TiO2 as-plated > Ni-P-TiO2 heated > Ni-P as-plated > Ni-P heated ~SS316L > MS. The better cost/strength ratio of Ni-P-TiO2 platings make these materials as more suitable for handling peroxide media with/without Cl content.