R & D of Super Duplex Stainless Steel Coil for Deep-sea Umbilical Cable

Based on the requirements of the mechanical properties and pitting-corrosion resistance of the high performance super austenitic ferrite duplex stainless steel for underwater manifold of deep-sea umbilical cable，the alloy composition is designed and optimized. Adopting AOD furnace with Al deoxidation-calcium treatment and off-furnace refining，the key technologies for adjustment and control of integrated cold deformation of hot piercing-high temperature intermediate solution treatment，deformation and distribution are proposed. After hot piercing. As a result the high-performance S32750 super austenitic ferrite duplex stainless steel seamless pipe for deep-sea manifold service as produced with the abovementioned processes possesses rather high mechanical properties and excellent pitting-corrosion resistance，having met the applicable specification of deep-sea oil and gas production and been adaptable to the deep sea service in the harsh seawater medium environment.