POSCO develops first armor steel for naval ships
Hyundai Steel leads the way in armored vehicles and tanks
SeAH Group establishes a special alloy plant in the USA

Korea’s steel industry is seeking new opportunities with differentiated high-value-added special steel for aerospace, defense, and nuclear power plants.
According to steel industry sources, major steelmakers such as SeAH, POSCO and Hyundai Steel are rapidly restructuring their business portfolios, prioritizing special steel for aerospace, defense, and nuclear power.
SeAH Group, which primarily produces shape steel and steel pipes, is at the forefront of this restructuring. SeAH Changwon Special Steel, a special steel affiliate, is constructing SeAH Super Alloy Technology, a special alloy plant for aerospace, in Temple, Texas.
The company plans to start commercial production in the second half of this year and directly supply local aerospace and defense companies. Orders from leading aerospace companies such as SpaceX are also anticipated.
SeAH Changwon Special Steel supplied a prototype of a 900℃ high heat-resistance alloy for aircraft engines to Hanwha Aerospace last year.
POSCO has also opened the door to the market of special steel for naval ships by developing the first higher-ductility hull structural steel and armor steel in Korea. Armor steel is 30% thinner than existing steel plates for ships but has the same bulletproof performance. Its application to upper structures of naval vessels aims to enhance protection power, while improving restoration of ships by reducing weight.
The company is also expanding its presence with steel materials for energy that can withstand extremely low temperatures. ‘High manganese steel,’ developed by the company itself, is a material that adds a large amount of manganese to steel so it does not break even at temperatures of -196˚C.
Hyundai Steel is also focusing on special steel for defense in response to slowing demand for construction and automobiles. Hyundai Rotem started supplying rear plates for armored vehicles in 2024. It also plans to begin mass-production and supply of rear plates for tanks this year, with development completed last year.
The domestic steel industry’s shift to high-value-added materials for aerospace and defense is seen as a survival strategy to escape the ‘negative growth tunnel’ caused by intensive supply of low-priced general-purpose goods from China.
According to the Financial Supervisory Service’s E-disclosure, the combined sales of Korea’s big four steelmakers ― POSCO, Hyundai Steel, Dongkuk Steel and SeAH Steel ― totaled KRW 70.98 trillion last year, a 3% decrease from the previous year, recording negative growth for three consecutive years.
An official from the steel industry explained, “It is difficult to withstand price competition with latecomers such as China and India only with general materials. Supplying special steel with high technology thresholds such as aerospace materials and armor steel for naval ships will determine the next 10 years of K-steel.”

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