In the relentless pursuit of safer and more efficient energy infrastructure, a team of researchers has shed new light on the behavior of austenitic stainless steel under corrosive conditions. The study, led by DENG Zhiwei of the Boda Oil and Gas Management Area of Tarim Oilfield Company and SONG Xiaojun of Shanghai Lanya Petrochemical Equipment Testing Institute, focuses on the pitting susceptibility of 304L and 316L stainless steel—materials widely used in pressure vessels and pipelines in the energy sector.
The research, published in *Cailiao Baohu* (translated as *Materials Protection*), employed electrochemical methods to measure the critical pitting temperature (CPT) of these stainless steels in a chloride-rich environment, a common corrosive agent in industrial settings. The team established evaluation curves to predict pitting susceptibility, which were further refined through chemical immersion tests. The findings reveal that as temperature or chloride concentration increases, the protective passivation film on both 304L and 316L stainless steel weakens, making them more prone to pitting corrosion.
“This study provides a clearer understanding of how environmental factors influence the longevity of stainless steel in critical applications,” said DENG Zhiwei. “By refining our evaluation methods, we can better predict material performance and make more informed decisions in material selection for pressure vessels and pipelines.”
The research highlights a significant temperature difference—ranging from -10 to 23°C—between the electrochemical and chemical immersion methods for determining CPT within the experimental chloride concentration range. Both methods confirmed that higher chloride concentrations lower the CPT, though the rate of decrease slows as concentration rises. The impact of chloride ions was found to be more pronounced at medium and low concentrations, a critical insight for industries operating in varying environmental conditions.
For the energy sector, these findings are particularly valuable. Pressure vessels and pipelines are subjected to extreme conditions, and understanding their susceptibility to corrosion is essential for ensuring safety and efficiency. “This research offers a more precise framework for assessing material performance, which could lead to longer-lasting infrastructure and reduced maintenance costs,” added SONG Xiaojun.
The study not only provides theoretical guidance but also practical data to support material selection under real-world operating conditions. As the energy sector continues to push the boundaries of efficiency and safety, this research could shape future developments in material science and engineering, ensuring that infrastructure remains resilient against corrosion.