POSCO and HD Hyundai Heavy Industries are betting their steel expertise can crack the naval defense market, signing an agreement to develop high-manganese steel for military vessels at a Busan defense exhibition last week.
The partnership aims to adapt technology POSCO originally created for liquefied natural gas storage tanks, positioning the material as superior to conventional ship steel. High-manganese steel is about 30% less expensive than nickel steel and maintains excellent impact toughness and strength even in extreme environments below minus 160°C, according to the companies.
The steel’s non-magnetic properties could help naval vessels evade detection by sea mines that respond to magnetic fields. High-manganese steel also has 10% higher strength compared to regular ship-grade steel, making the hull less susceptible to external impacts or explosions.
Yet challenges remain. Mangalloy’s uses are often limited by its difficulty in machining, sometimes described as having “zero machinability”. The material requires specialized cutting tools and techniques, potentially complicating shipyard operations.
POSCO developed the technology starting in 2008, anticipating growing LNG demand. Whether defense contractors will embrace the more complex manufacturing requirements for potentially marginal performance gains remains unclear. The Korean companies face established competitors with proven naval steel technologies already deployed across global fleets.
