The 9% Ni steel developed in December 2020 is widely used as a material for LNG storage tanks thanks to its excellent durability against impact in ultra low temperatures (-196 ℃) and outstanding welding performance.
While demand for LNG is rapidly increasing due to it emitting fewer pollutants compared to conventional diesel fuel, technological restrictions apply to using it as fuel for ships since the interior of the storage tank needs to be maintained at below -165 ℃.
In February, Hyundai Steel signed a contract to supply 9% Ni steel as fuel tank material for an extra-large LNG-propelled container ship that Hyundai Heavy Industries is building, the first supply already provided in June. The amount that Hyundai Steel will supply, 2,100 tons, is for two extra-large LNG-propelled container ships. The company has developed the product through two-way early vendor involvement (EVI)* activities, including a quality assessment meeting with the client before supplying the product and a reflection of the client’s quality requirements in production.
Having extremely strict quality requirements, this product used to rely entirely on importation. Since signing the contract, Hyundai Steel will be the first Korean steel company to supply the Type B fuel tank* material, which is expected to generate an import-substitution effect in related material markets in the future.
Following this contract, Hyundai Steel is planning on actively tackling related LNG markets that are sharply rising in demand, including LNG-propelled ship fuel tanks and land storage tanks used for LNG plants and LNG terminals. A company official said, “We are planning on making additional investments in heat treatment facilities to expand the supply of 9% Ni steel, and by doing so, plan to actively respond to the increase in demand for ship LNG fuel tanks and land storage tanks in the future.”
※ Early Vendor Involvement(EVI): Joint product development
※ Type B Fuel Tank: The International Maritime Organization (IMO) classifies the LNG fuel tank of ships into two types: “membrane tank” and “independent tank.” The independent tank comes in three types: “Type A,” “Type B,” and “Type C.” Large container ships use the Type B fuel tank, which can be designed and manufactured in a prism shape and with fewer form limitations.
Nine percent Ni steel, which is used as the fuel tank material for Type B and Type C, requires strict quality standards, particularly in terms of its flatness and residual magnetic field, for the physical properties of the final product. Specifically, the Type B tank requires extremely strict surface quality, demanding a much greater level of technological prowess.