Adsorption of Calcium Particles on A36 Mild Steel and its Thermodynamic Parameters

Abstract

Adsorption behavior of Ca particles obtained from SS, PS and ES calcination, as well as its Td parameters, during A36 MS coating via phosphating process, was investigated. A36 MS coupons surfaces were coated with phosphates and varied C of Ca particles (from 1 to 2.5 g/dm 3 ), at a T of 60 and 80 C. Ca particles (as inhibitor) adsorption onto the MS surface obeyed Freundlich's isotherm, with R 2 values around 1. Kads and Td parameters, such as G, H and S, were also determined. A36 MS coated with Ca particles obtained from calcined SS gave the best A capacity, as revealed in terms of Kads, G and S values. Higher Kads was obtained when T increased from 60 to 80 C. Also, Td parameters results revealed that Ca particles adsorption mechanism on MS was a more spontaneous process, at an increased T of 80 C.