THE EFFECT OF ROUGHNESS ON THE PHYSICOCHEMICAL PROPERTIES OF A36 STEEL: PHOSPHATE ADHESION STUDY

This work discusses the effect of surface roughness and surface physicochemical properties on the initial adhesion of phosphate to steel. The steel samples used in this study are made from A36 low alloy steel. The phosphate was extracted from the BenGurir-Morocco area and is used in this work in the form of pellets that were compacted using different pressures. The steel surface is treated by two methods of surface pretreatment such as honing and horizontal milling. The influence of this pretreatment procedure on the surface morphology, roughness, surface energy and hydrophobicity are examined. By measuring the contact angle on the surfaces of the phosphate pellets and the substrates of low-alloy A36 steel, we were able to identify the physicochemical parameters by calculating the surface energy. In addition, the roughness of each steel sample was investigated using the roughness meter and the metallurgical microscope. The results obtained showed that the phosphate surface is is subject to dispersing forces and has a hydrophilic character. For the surfaces of different A36 steel substrates, the effect of roughness was well examined, the minimum surface energy was obtained for both pretreatment (honing and horizontal milling) for a determined roughness. This result can be used for preparing surfaces with minimum surface energy in order to minimize fracture energy and therefore minimize the adhesion and clogging of the phosphate on steels.