By 2025, stainless steel technological innovation is shifting from ‘single-property optimisation’ to ‘comprehensive performance enhancement’. Breakthroughs in high-nitrogen alloys by North Heavy Industries Group, nanocrystalline technology by the Chinese Academy of Sciences, and dual-phase steel by Taiyuan Iron & Steel have addressed the industry's longstanding challenges of ‘strength-toughness imbalance’ and ‘corrosion resistance versus cost trade-offs’ through three distinct pathways: composition substitution, microstructural control, and structural innovation. These advancements inject fresh momentum into high-end manufacturing.Composition innovation replaces nickel with nitrogen, pioneering a low-cost pathway to high-end production. Through collaboration with universities, North Heavy Industries Group has mastered atmospheric pressure melting technology for high-nitrogen stainless steel, achieving stable production with nitrogen content exceeding 0.85%. Substituting scarce nickel resources with nitrogen reduces raw material costs by over 30%. This high-nitrogen, non-magnetic austenitic stainless steel exhibits a 40% increase in tensile strength compared to traditional 304 grade, surpasses 316L in seawater corrosion resistance, and maintains excellent toughness after cold working. It is now supplied in bulk for deep-sea equipment and naval vessel construction, breaking foreign monopolies on high-pressure smelting technology. This technology eliminates the need for specialised pressurisation equipment, significantly enhancing production safety and efficiency. It holds promise for establishing an industrial cluster centred on high-nitrogen alloys.Microstructural control has overcome bottlenecks, achieving synergistic performance enhancements. The Institute of Metal Research, Chinese Academy of Sciences, has produced martensite-free nanocrystalline 304 stainless steel plates through precise rolling process control. This marks the first global resolution to the challenge of reconciling mechanical strength with corrosion resistance in nanomaterials. Compared to conventional 304 stainless steel, this material exhibits a 50% improvement in high-temperature oxidation resistance, a twofold increase in strain fatigue life, while maintaining an elongation rate exceeding 12%. This material can be directly applied to critical components such as aero-engine blades and high-end bearings, driving equipment towards lightweight and extended service life. Concurrently, the Institute of Mechanics at the Chinese Academy of Sciences employed ultrasonic coupling additive manufacturing to construct cross-scale heterogeneous structures within 316L stainless steel. This technique achieved a gradient distribution of millimetre-scale grains and nanoscale precipitates, delivering an outstanding combination of 1GPa tensile strength and 12.5% elongation.Structural innovation focuses on duplex steel to meet extreme application demands. TISCO has achieved multiple breakthroughs in duplex steel, not only mass-producing 115-millimetre ultra-thick super duplex steel plates but also developing the cost-effective S32202 grade, successfully supplied to Qatar's chemical storage tank project. This dual-phase steel combines the toughness of austenite with the strength of ferrite, exhibiting stress corrosion resistance over three times that of 304 stainless steel. It facilitates import substitution in sectors such as petrochemicals and offshore platforms. Qingtuo Group has applied its economical duplex steel to new energy heavy-duty truck chassis, achieving a 30% increase in tensile strength compared to traditional carbon steel. This enables ‘long-term service without coating’ in coastal high-humidity environments, reducing vehicle weight by 15% while cutting maintenance costs by 60%.From compositional optimisation to microstructural reconstruction, stainless steel technological innovation is redefining material performance boundaries. These breakthroughs not only resolve bottlenecks in high-end materials but also drive deep application in strategic sectors like defence, new energy, and offshore engineering through dual advantages of cost reduction and performance enhancement, providing core material support for manufacturing upgrades.