Laboratory testing was used to demonstrate the differences in corrosion rate of typical zirconium 702 (R60702) containing approximately 2400 ppm tin, and low-tin zirconium 702 containing approximately 1400 ppm tin. Sample material was heat-treated at 770ºC for 1 hour. Standard immersion testing was conducted in 60-70% sulfuric acid at boiling temperatures. Autoclave testing was performed at the same concentrations of acid, but at temperatures up to 180°C. Updated 5 mpy isocorrosion curves for zirconium in sulfuric acid are presented. The effect of heat treatment on corrosion resistance in sulfuric acid applications is discussed.
Keywords: Zircadyne-702®, zirconium, tin, sulfuric acid, heat-treatment, corrosion