STUDY OF THE EFFECT OF TEMPERATURE ON THE HARDNESS, GRAIN SIZE, AND YIELD IN ELECTRODEPOSITION OF CHROMIUM ON 1045 STEEL

Abstract

A study was made on the effect of temperature on the electrodeposition of hard chromium on 1045 steel within a range of 30 degrees to 60 degrees C., as shown by variations in reaction yield, surface hardness, and depositional grain size. Increase in temperature produced a decrease in faradic yield of the reaction of between 17% and 9%, an increase in hardness from 550 to 700 Brinelli, and a decrease in deposited chromium grain size from 278 to 32.4 mu m. The most notable effect of temperature difference was observed between 30 degrees and 40 degrees C. Chrono-potentiometric and poteniodinamic linear sweep were measured at 30 degrees C, 40 degrees C and 50 degrees C in an attempt to explain this behavior. The results obtained suggested the formation of a compact film typical of a nucleation process in chromium electrodeposition. An increase in temperature affects the formation of this film, decreasing its thickness and distributing it in a more homogeneous manner over the steel, as shown by a decrease in the grain size of the chrome deposited.