Indian researchers have developed a new ultra-low carbon stainless steel that combines exceptional strength, flexibility and corrosion resistance for aerospace and defence applications.
Scientists from IIT Kharagpur, IISc Bengaluru and ISRO mapped how microscopic changes inside precipitation-hardened martensitic stainless steel evolve under precise heat treatment. By subjecting the steel to sub-zero processing followed by ageing between 482°C and 621°C, the team identified an optimal temperature window that balances strength and toughness.
At controlled ageing temperatures of 510–593°C, tiny Ni₃Ti precipitates strengthen the steel while a softer phase, known as reverted austenite, enables a TRIP effect. Under stress, this phase transforms and absorbs energy, preventing cracks and improving impact resistance, which is critical for rocket casings and satellite structures operating in deep space.
The study also establishes an upper temperature limit, beyond which toughness drops sharply. Importantly, the steel offers built-in corrosion resistance, eliminating the need for toxic coatings. The research provides a clear manufacturing roadmap for next-generation space-grade components.
