403 Stainless Steel Coil is a martensitic stainless steel specifically formulated for high-temperature steam turbine applications, offering an optimal balance of strength, hardness, and corrosion resistance. With a controlled composition of 11.5-13.0% chromium and reduced silicon content compared to similar grades, 403 provides excellent resistance to scaling and oxidation at elevated temperatures while maintaining good mechanical properties and fabricability. Originally developed for steam turbine blades and other high-stress components in power generation equipment, this grade has become the standard for applications requiring reliable performance in demanding thermal environments.

Supplied in continuous coil form, 403 stainless steel combines the heat treatability and strength of martensitic stainless steels with improved high-temperature stability compared to standard 410 grade. Its carefully controlled chemistry minimizes delta ferrite formation, ensuring consistent mechanical properties and dimensional stability during heat treatment. While primarily associated with power generation, 403 has found applications across various industries where components must withstand combination of stress, temperature, and mildly corrosive environments, offering a cost-effective alternative to more highly alloyed materials.