Estudio de la agresividad corrosiva en medio salino de planchas galvanizadas en caliente, sometidas a esfuerzos de tensión

Abstract

Steel coatings are one of the most technics used for protection on elements and steel structures, one of them is the galvanized for Hot-dip process. 55%Al-Zn coated is the most used in the industry for protection on frames, gutter, ceilings and other. These materials are exposed to highly risk environmental conditions like that we have in the Coast. For the this project we used specimens made of steel sheets grade 230 with a AZ150 coating given for the ASTM A792M which ones have a double colored Surface that we named as normal and stained, with different tension stress, in an accelerated salty environment with a solution of 5%NaCl dissolved in water; based on ASTM G49-85 with the purpose of testing the corrosion resistance for each kind of Surface. The test was made in a spray fog chamber at 35 °C for an exposure period of 70 days, to 15 specimens with loads between 0 to 10 N-m; the specimens were inspected every 7 days to watch the corrosion process. The evaluation was made using a photographic register, microindentation test, chemical composition and metallographic test; where we watched that the stained specimens showed a less corrosion resistance and another cases they get broken.