The QN series is an economical nitrogen-alloyed high-strength austenitic stainless steel series globally launched by Tsingshan Group (a subsidiary of Tsingshan Holding Group). The core product, QN1803, was first introduced in 2018-2019, marking an innovative shift for Chinese stainless steel grades from following to leading. This series utilizes nitrogen alloying technology to replace expensive metals like nickel and molybdenum with nitrogen, significantly enhancing performance while reducing costs. It has been incorporated into the national standard GB/T 20878-2024.

QN Series Stainless Steel Composition Table

1. High Strength & Nickel Saving: Yield strength generally reaches 355-400MPa or higher (approximately 1.5 times that of traditional 300 series), with significantly reduced nickel content, offering clear cost advantages.
2. Excellent Corrosion Resistance: Pitting Resistance Equivalent Number (PREN) ranges from 15 to 30, reaching levels comparable to 201/430, 304, 316L, and 317L respectively; nitrogen inhibits chromium carbide precipitation, providing strong intergranular corrosion resistance.
3. Good Processability: Elongation exceeds 50%, excellent cold working performance allows for thickness reduction strengthening, further lowering overall costs.
4. Low-Temperature Toughness: Maintains good toughness even in extremely low-temperature environments down to -200°C, offering a wide application range.

Widely applied in six major areas: strip, decorative welded pipes, wire rod, steel bars, sections, seamless tube billets. Specific scenarios include:

• Home Appliance Manufacturing (e.g., Midea dishwashers exported to North America)
• Building Decoration (curtain walls, doors/windows, roofing)
• Food Machinery, Paper Storage Tanks, Elevator Components
• Marine Engineering, Energy Equipment, Precision Parts for Smart Equipment

QN Series Pitting Potential Diagram

Stainless Steel Corrosion Performance Test

Compared with benchmarked grades, QN series steels maintain equivalent or higher Cr and N content. While nickel content is reduced, QN series steels still achieve a higher PREN value, ensuring superior corrosion resistance. With high strength, high corrosion resistance, and high cost-effectiveness, lightweight design is possible, achieving at least a 10% thickness reduction.

Actual Environmental Corrosion Performance of New Stainless Steel Materials - (0.5km from coast coupon test, Ningde, Fujian)
Marine atmospheric environment (5 months) coupon photos: 410S, J3, J2 showed significant rust after two weeks; 430 showed slight rust spots after one month; after 3 months, QN1701, 304J1, 304, 304DQ, QN1803 all showed a few rust spots; 316L, QN1906 and higher grades did not rust.
In offshore environments, at least QN1906/316L or higher grade stainless steel is required.

After two years of promotion, the application fields of QN series stainless steel continue to expand. It is now widely used in building envelopes, industrial refrigeration containers, agriculture and animal husbandry, electrical equipment, and other fields.

• Application of QN1803 in Refrigeration Containers

• Application of QN1803 in Municipal Engineering

• Application of QN1701 in Elevators

• Application of QN Series Stainless Steel in Livestock Farms

       Outdoor roofing is primarily subject to atmospheric corrosion; ceiling tiles, railings, curtain walls, and troughs are in contact with the farm environment, where corrosion is more severe. Using QN series stainless steel can significantly slow down the corrosion rate.

• Application of QN Series Stainless Steel in Home Appliances

• Application of QN Series Stainless Steel in Industrial Fields