Each month, Stainless Solutions from IMOA covers a different stainless steel issue with tips on design and specification, and links to technical resources. This month’s issue will explore the performance of higher-alloyed stainless steel curtain wall applications in China.
Pollution, acid rain and airborne particulate levels remain very high in fast-growing economies around the world and create very corrosive conditions. When combined with coastal or deicing salts, the service environment for materials becomes even more demanding. About 60% of China’s population is located in coastal zones. China is also the world’s largest producer of deicing salt, which is increasingly being used on the country’s roadways in winter.
Materials that perform well in countries with lower pollution levels can deteriorate quickly under these conditions. IMOA’s web pages on stainless steel selection, coastal locations, deicing salt and the Nickel Institute brochure Guidelines for Corrosion Prevention assist with stainless steel selection in demanding environments.
While literature provides guidance, the best way to compare material performance is to look at actual buildings in representative service environments that are at least ten years old. It is important to look at examples of all of the materials that are being considered and to ask questions about any maintenance, replacement or recoating that has occurred.
Eight Chinese reference projects are listed via the link below by year of completion. The designers understood the severity of the environment and selected Type 316 or more corrosion resistant stainless steel alloys. The level of maintenance carried out on these projects varies significantly but simple cleaning can restore stainless steel’s appearance.