At a shipyard in Mokpo on December 11 2020, a ship naming ceremony was held for two vessels that received the name of HL ECO and HL Green. Both vessels, able to carry up to 180,000 tons, are the world’s first LNG powered bulk carriers, as well as eco friendly carriers that POSCO has preemptively introduced to replace conventional ones. POSCO’s 9% nickel steel was applied as materials for the fuel tanks of the vessels, whereas 42,000 tons of POSCO steel plates were used in the bodies. The ships, HL ECO and HL Green, will transport iron ore and coal to steelworks, traveling between Korea and Australia.
It took two years for POSCO to introduce two LNG-powered vessels. In June 2018, an agreement was signed between the Ministry of Oceans and Fisheries, POSCO, H-Line, and KOGAS. From December that year, Hyundai Samho Heavy Industries began building the ship, and exactly two years later, POSCO could hold the ship naming ceremony. POSCO is currently participating in the low carbon & eco friendly policy even in the ocean by installing exhaust gas cleaning systems on 20 vessels, which is more than half of the total carriers, and by utilizing LNG and low sulfur fuel in the remaining raw material ships.
9% nickel steel is the most widely used steel for producing LNG storage tanks since it maintains outstanding strength and toughness even at extremely low temperatures that reach minus 163 degrees Celsius. 9% nickel steel could only be produced by few steelmakers in the past, so domestic shipbuilders had to depend on imports. However, POSCO succeeded in developing it for the first time in 1993, and after quality stabilization, production for the material has been accelerated from 2007. Recently, POSCO has been in active cooperation with the Big 3 shipbuilders in Korea to develop technology for LNG storage tanks using this material. By applying POSCO 9% nickel steel on the world’s first LNG-powered bulk carrier, POSCO has succeeded in material localization.
According to the regulations of the International Maritime Organization, only nickel alloy steel, stainless steel, 9% nickel steel, and aluminum alloy steel were permitted to be used as cryogenic materials for LNG tanks on board an LNG carrier. But there is one material that received approval two years ago, POSCO’s own high manganese steel. While 9% nickel steel has a downside of being expensive and unstable supply and demand, high manganese steel is about 30% more economical than 9% nickel steel. Its supply and demand are also stable due to its rich reserves. In December 2017, POSCO succeeded in applying high manganese steel to LNG tanks of the 50,000-ton Green Iris, the world’s largest LNG powered bulk carrier at the time.