Xingcheng Special Steel's world's largest thickness 9Ni stee

International first! Xingcheng Special Steel's world's largest thickness 100mm 9Ni steel for pressure-bearing equipment

 

Recently, Xingcheng Special Steel successfully adopted continuous casting technology to produce and develop 100mm thick 9Ni steel and passed the type test certification of nine classification societies such as CCS and ABS, breaking through the specification limit of the maximum thickness of the classification society of 50mm, filling the gap in domestic and foreign products in this field, marking Xingcheng Special Steel's major breakthrough in the field of nickel-based low-temperature steel for ultra-thick pressure-bearing equipment.

 

Marine 9Ni steel is mainly used for the storage and transportation of liquefied natural gas. It is one of the products with the highest technical level, the greatest difficulty and the highest added value among civilian steel products. In 2019, the capacity of China's largest LNG storage tank was only 160,000 cubic meters, and in 2022, the LNG storage tank has developed to 270,000 cubic meters. The thickness of steel plates used in land-based LNG storage tanks is usually 5 to 36 mm. The capacity of offshore mobile storage tanks and fuel tanks is generally only a few thousand cubic meters, but they are much thicker than land-based storage tanks. The maximum thickness of the tanks currently under construction has reached 56 mm, which exceeds the specification range of classification societies (≤50 mm). In the future, the trend of nickel-based low-temperature steel for pressure-bearing equipment is obvious to develop in the direction of greater thickness, and the demand will increase year by year.

 

Due to the flammability and ultra-low temperature of liquefied natural gas, compared with general low-temperature pressure vessels, the low-temperature steel used for its storage and transportation must have comprehensive characteristics such as strength, thermal stress and strain, welding performance and corrosion resistance. In special important structures, in order to prevent accidents, the material must also be required to have brittle crack propagation resistance. Therefore, whether such products can be produced is an important symbol of the overall technical level of a steel enterprise. 9Ni steel has extremely high requirements for low-temperature impact toughness and extremely strong crack sensitivity of ingots, and has long been monopolized by foreign countries. Only in recent years, enterprises with strong R&D strength in medium and thick plates such as Xingcheng and Nangang have been localized and have been substantially applied.

 

Xingcheng Special Steel combines its special steel smelting experience, first-class equipment advantages and characteristics, and continuously conducts in-depth research and development and technical reserves for high-quality 9Ni steel. It has successfully developed 9Ni steel with a maximum thickness of 100mm for pressure-bearing equipment and passed the type test certification of nine classification societies. This is another leap forward in Xingcheng Special Steel's practice of developing highly difficult medium and thick plate products, indicating that the medium and thick plate production technology has reached the world's first-class level. It will further lead the research and development of a series of steel grades with the characteristics of clean steel, high alloy and high surface quality, which is of great significance to the optimization and upgrading of the medium and thick plate product structure.