This work focusses on understanding corrosion severity and material performance within model geothermal sulfuric acid (H2SO4)-containing environments. With the use of a tantalum-lined high pressure/high temperature autoclave, the corrosion behavior of N80 carbon steel was compared against duplex stainless steel when exposed to H2SO4 solutions (pH 2-4) at temperatures up to 150°C. Electrochemical linear polarization resistance measurements were implemented to gather real time corrosion kinetic data. Complimentary ex-situ analyses (scanning electron microscopy and white light interferometry) were conducted to understand the corrosion mechanism and quantify localized corrosion rates. A quantitative relationship was identified in terms of pH, temperature and metal corrosion for the selected materials to highlight material capability within such low pH geothermal environments.