Electrodeposition of Iron-Chromium Alloys from Sulfate Bath

Abstract

The object of these experiments was to obtain Fe-Ni-Cr alloys, having higher corrosion resistance. The first step for this object was the investigation on the deposition of Fe-Cr alloys, which is reported in this paper.From the standpoints of abating the public nuisance, the study was performed with a bath containing an electrolyte of sulfate, and the following results were obtained.(1) A bright deposit of Fe-Cr alloys, containing about 20% of chromium, was obtained.(2) Current efficiency was 20-30%.(3) The hardness of the deposit was above 700 in Vickers value.(4) The addition of aluminum sulfate was effective among inorganic addition agents.(5) The optimum condition of bath composition and electrolysis available was as follows.Ferrous sulfate 83g/l Sulfuric acid 30-50g/lChromic sulfate 140g/l pH 1.8Urea 180g/l Current density 30-35A/dm2Ammonium sulfate 265g/l Temperature 40-50°CSulfuric acid was used for adjusting pH.