Diseño del proceso químico de galvanizado en por inmersión en caliente de piezas industriales para la empresa PCA company S.A.

Abstract

The objective of this curricular integration work is to carry out the preliminary design of the chemical process of hot galvanizing, of metal parts for the Enterprise PCA Company SA. It consists of an experimental study to obtain the variables of the chemical pretreatment operations and coating of the parts with molten zinc. Rectangular pieces of dimensions 20x50mm and thickness of 3mm of carbon steel were used. Eighteen pieces were selected that were subjected to two different methods of chemical pretreatment. The sequence of the chemical pretreatment process is: degreasing, first rinse, pickling, second rinse and fluxing; each stage has a working temperature for the treatment solution and an immersion time. The molten zinc coating process consists of the following stages: drying, coating and cooling; the oven works at a temperature of 450 degrees Celsius. The results for the pretreatment show that the surface characteristics of the metals treated by the basic and acid method differ considerably. The plates treated with the basic method maintained their metallic luster and the parts treated with the acid method had a dark surface. In the coating test, three replications were performed, only the plates from the last test showed compliance with the INEN ISO 1641 norm, with an average coating mass for the plates treated with the basic method of 530.54 g / m2 (74.31 micrometers) and the acid method of 532.43 g / m2 (74.57 µm). In conclusion, the chemical process of a hot dip galvanizing plant was designed and it is recommended to carry out more in-depth studies of the zinc coating process mixed with chromium, tin and other metals.