Effect of solution treatment period on Magnesium anode in soil environment

Abstract

The aim of this study is to determine the effect of heat treatment on the corrosion rate using immersion test in soil and backfill environment. Samples were heat treated at 300°C for 3, 6 and 9 hours in high temperature oven. The samples were quenched into distilled water and aged at 150°C for 8 hours. The samples were immersed in soil and backfill solution for 5 – 15 days. The samples were weighted at certain interval times. Corrosion rate was determined based on ASTM G31-72. The result shows sample without solution treatment and aged process was exhibits high corrosion rate (395.428 mpy) compared to the other samples that immersed into backfill environment as designation 1A. The deepest pitting (1280.6 µm) occurred on sample that done the aged process at 300°C at 8 hours and immersed into backfill environment as designation 1B. Result from immersion test of soil environment show lower value of corrosion rate than backfill environment and not happen pitting corrosion at sample’s surface. Thus it’s suggested the next experiment to use the designation 1A and 1B to determine the corrosion rates and pitting depth for another corrosive environment.