Duplex stainless steel is increasingly favored by users because of its long service life, high strength, light weight, good welding performance, corrosion resistance, maintenance-free and environmental protection. TISCO is the first company in China to develop and produce duplex stainless steel. In recent years, a large number of research and development and promotion work have been carried out in terms of variety structure, specifications, quantity and application fields, and many key technologies have been broken. The manufacturing process ranks among the world's first. The products have been successfully applied to the Hong Kong-Zhuhai-Macao Bridge and the world's largest tonnage. Major projects at home and abroad such as chemical tankers, Oman natural gas pipelines, and PetroChina Tarim Oilfield Natural Gas Reconstruction Project.