Development and characterization of chromium-free layers applied on galvanised steel

• Grant number: 16/50454-6
• Support type: Regular Research Grants
• Duration: February 01, 2017 - January 31, 2019
• Field of knowledge: Interdisciplinary Subjects
• Cooperation agreement: University of Surrey
• Mobility Program: SPRINT - Projetos de pesquisa - Mobilidade
• Principal researcher: Célia Regina Tomachuk dos Santos Catuogno
• Grantee: Célia Regina Tomachuk dos Santos Catuogno
• Principal researcher abroad: Mark Alan Baker
• Institution abroad: University of Surrey, England
• Home Institution: Escola de Engenharia de Lorena (EEL). Universidade de São Paulo (USP). Lorena , SP, Brazil
• Associated research grant: 15/09952-0 - Surface treatment process for application in zinc coating environmentally friendly, AP.R

Abstract

Conversion processes are very important, both as a means of protection against corrosion and for the surface preparation for paint application. Many commercial surface treatments currently use electrolytes containing hexavalent chromium salts. However, although effective, these processes are in the process of being banned from industrial use due to the toxic and carcinogenic properties of the residues generated. The literature shows the proposed new processes do not produce surface layers with the same corrosion protection properties as the chromate conversion layers. Besides, the layers formed by the new proposed processes do not offer similar adhesion to organic coatings. The aim of this project is to obtain conversion layers from electrolytes free from hexavalent chromium salts, which show similar corrosion protection to that of the currently used chromate conversion coatings, meeting environmental demands but allowing the use of the installed electroplating lines in galvanic industries. The alternatives to be tested are electrolytes containing cerium salts using a chemical deposition process. (AU)