Corrosion behaviour of aged A297HF stainless steel in a chloride environment

THIS PAPER discusses the influence of the thermal-ageing process on the corrosion behaviour of heat-resistant A297HF stainless steel in a chloride environment, The results of the slow-strain-rate test and electrochemical analysis indicated that under the condition of free corrosion potential in 0.5M chloride solution at 25 degrees C, stress-corrosion cracking occurs in an aged (A297HF) alloy with carbide precipitation, but not in those with prime precipitation or via solid-solution treatment (at 1200 degrees C). Under anodic polarization, the stress-corrosion cracking occurred in an aged alloy with carbide precipitation more easily than in those with prime-phase precipitation or via solid-solution treatment. Under cathodic polarization potential, hydrogen embrittlement was observed in an aged alloy with prime-phase precipitation or via solid-solution treatment, while strong cracking resistance was observed for the aged material with carbide precipitation.