At approximately 8:30 a.m. on December 26, employees at ZTE Energy Equipment Co., Ltd. methodically packed four large-diameter, thin-walled seamless super duplex steel pipes (specifications: 1016mm × 9.53mm) into crates within the workshop. This breakthrough product—filling an international gap and overcoming critical bottleneck technologies—will be shipped overseas via air freight.

With over 30 years of expertise in high-end steel pipe manufacturing, ZTE Equipment targeted the demanding stainless steel pipe market for nuclear power, marine engineering, and liquefied natural gas sectors as early as 2022, initiating technological development efforts. After three years of dedicated research, the team successfully overcame multiple technical barriers, achieving domestic production of these high-end products and breaking foreign technological monopolies.

In April this year, after approaching multiple globally renowned manufacturers without meeting its requirements, a European nuclear power company sought out ZTE Equipment based on its reputation and immediately signed an order exceeding 100 million yuan for nuclear-grade stainless steel pipes. The large-diameter, thin-walled seamless super duplex steel pipes being shipped now form a crucial part of that order.

Cui Bin, Director of the company's Technology Center, explained: "The R&D and production of this product faced multiple technical challenges, including the difficulty of precisely controlling material composition, the complexity of forming large-diameter thin-walled pipes, and stringent requirements for ensuring performance in extreme environments. Leveraging our robust technical capabilities, we not only shortened the delivery cycle to two months but also significantly reduced costs. During production, the company employed multi-stage refining to precisely regulate material composition. Innovative techniques—including high-temperature piercing rolling, cold spin rolling, and online solution treatment—strictly controlled wall thickness deviations within technical specifications, rapidly locked in the duplex microstructure, and effectively prevented harmful phase precipitation. Simultaneously, a comprehensive quality control system was established, featuring an integrated “composition-process-performance” database. Real-time production monitoring utilizes infrared temperature measurement and ultrasonic flaw detection, with key indicators exceeding international standards.

The successful shipment of these large-diameter, thin-walled super duplex stainless steel seamless pipes signifies China's complete resolution of critical material bottlenecks for seamless stainless steel pipes in major engineering sectors like nuclear power, deep-sea oil and gas, and LNG. This achievement will significantly advance the industrial upgrading of high-end duplex stainless steel and provide robust deep-sea equipment material support for China's strategy to become a maritime power. This inaugural export not only represents a significant breakthrough for China's high-end manufacturing “going global” but also offers a reliable “Chinese solution” for extreme-environment engineering worldwide.