Recently, POSCO proved its unrivaled steel material technology by becoming the first in Korea to obtain Korean Register (KR) certification for its new naval materials: high-ductility steel for naval vessels and armor steel for naval vessels. The application of these new materials is expected to drastically improve the performance of the Republic of Korea (ROK) Navy’s next-generation vessels. How were these steel plates, which withstand extreme water pressure and strong external impacts, born? We sit down with Lee Jae-ik and Lee Jin-woo, Principal Researchers at POSCO’s Steel Solution Research Group, to take a closer look at POSCO’s core competitiveness and future vision leading K-marine defense materials.

Lee Jae-ik: Hello. I research “application technology” to help our customers perfectly implement thin yet strong “high-strength steel” into their products. Recently, as reducing the weight of structural frames for carbon reduction has become a major topic, the demand for high-strength steel has increased significantly. However, as steel becomes stronger, welding becomes more difficult, and even after successful welding, the fatigue life of the joints often fails to match the strength of the steel itself. I solve this exact problem. My role is to dramatically extend the fatigue life of high-strength steel welded joints, providing optimal solutions so that customers can safely use lighter and stronger steel for a long time.

Lee Jin-woo: Nice to meet you. I am Lee Jin-woo, researching customized customer solutions at POSCO’s Steel Solution Research Group. Our group’s role does not end with simply making good steel. We provide a comprehensive “user manual” containing the optimal technology and guidelines so that the material can perform at 100% capacity at the customer’s site.

Currently, my main areas of focus are twofold. First is next-generation material solutions for land-based weapon systems and special vessels (surface combatants) that lead K-defense. Second is the heavy equipment and construction machinery sector. In particular, by applying the “extreme environment response technology” and “structural optimization know-how” accumulated in the defense sector to construction equipment, we create synergy to maximize the durability and efficiency of the equipment when our steel is applied. In short, my role can be described as a “technological bridge” that transforms raw materials into core components for high-tech industries.

▲ Conceptual rendering of a next-generation naval vessel applying new defense materials.

Lee Jin-woo: This KR certification is a decisive moment showing that the role of naval materials has evolved from simple “structural materials” to “core functional materials” that determine combat capability. It also demonstrates that Korea’s naval shipbuilding technology has entered a new dimension through material innovation. In modern warfare, where advanced weapons are becoming more sophisticated, the evolution of the hull that protects them is a necessity, not an option. POSCO’s new materials have secured both defensibility and mobility. By increasing elongation to 35% and impact absorption capacity by over 50%, we secured strong survivability, while reducing hull thickness by 30% to dramatically improve mobility and fuel efficiency. Our materials are completing the super-gap of K-defense as core functional materials supporting weapon systems. I am confident that this will serve as a solid foundation for POSCO to leap forward as a key partner in the global defense export market, going beyond being a “steel shield” for Korea’s next-generation vessels.

Lee Jin-woo: POSCO’s new naval materials are evolving in a direction to develop stronger and tougher steel materials so that submarines can operate safely deep under the sea. First, high-ductility steel, which applies technology that remains intact even when colliding with glaciers, stretches much better than conventional steel (35% elongation) while its capacity to absorb impact has become over 50% stronger. In addition, high-performance armor steel, which transplants solid ballistic technology from land-based weapon systems to the marine sector, maintains its strength while reducing the thickness of the steel plate by approximately 30% compared to existing ones. Reducing the thickness of the steel plate enables lightweighting of the hull, thereby improving both mobility and fuel efficiency. This advancement in material technology symbolizes a paradigm shift from structural materials to core functional materials, and will be POSCO’s core competitiveness to contribute to expanding K-defense exports and entering the global naval vessel market in the future.

Lee Jae-ik: Since they are used at sea, both general shipbuilding heavy plates and special steel for naval vessels require high reliability. However, the core purpose of the materials is different. General shipbuilding heavy plates focus on optimizing “economic efficiency and stability” according to the waves or temperatures of designated routes. On the other hand, marine defense materials, such as surface combatants and submarines, must perform operations in any ocean worldwide and survive extreme combat situations like shell hits or explosions. Therefore, they require the most stringent standards in existence. While general shipbuilding mainly uses “high-efficiency steel” with good work efficiency such as welding, marine defense uses “premium special steel” containing a large amount of special alloys to boast the highest level of strength and toughness. This is the biggest difference.

Lee Jae-ik: The pressure hull, which is the framework of a submarine, must maintain its original shape firmly without fatigue or cracking to protect the crew and sensitive equipment from intense water pressure, explosions, and impacts. To achieve this, steel must possess a combination of strength to withstand water pressure (yield strength), flexibility without breaking (elongation), impact absorption capacity (toughness), and ease of bending without heat (cold formability). Perfect welding that connects joints as strongly as the original steel plate and technology to eliminate post-welding stress are also essential.

For example, Japan’s Taigei-class submarines apply ultra-high-strength steel (NS110, yield strength of approx. 980 MPa) that withstands depths of 500 meters. The core technology here is overcoming the problem of reduced flexibility as steel becomes harder. On the other hand, Germany’s Type 212/214 submarines used “non-magnetic steel” that does not stick to magnets to avoid detection based on the enemy’s magnetic field, but because of the limitations in the material’s strength, their diving depth is limited to about 250 meters. Ultimately, for a submarine to survive intact in extreme crisis situations such as undersea collisions, torpedo evasion, or rapid surfacing, advanced steel materials that balance hardness and flexibility, along with reliable welding technology, must be supported.

Lee Jae-ik: To prove the reliability of submarine materials, we must go through three stages of evaluation. First, we quantify the basic alloy design and physical properties using fingernail-sized “micro-specimens.” Second, once the steel is produced, we manufacture “full-thickness specimens” to directly test the limits of strength and toughness of the base metal and welded joints. Finally, we conduct “structural mock-up testing,” assembling it similarly to an actual submarine shape. In this stage, we final-check residual stress generated during actual processing, fatigue life, and deformation during explosions. As a result, to develop a single steel material, hundreds of similar items are repeatedly verified double and triple, and only after passing this harsh process can we finally take responsibility for the submarine’s survivability.

Lee Jae-ik: That is the most difficult part of development. This is because a vicious cycle occurs where increasing the strength of the steel plate makes it weak against impact, and compensating for this warps the welding. POSCO is breaking through this difficult limitation with two innovations. We are researching to secure both strength and toughness simultaneously through advanced Thermo-Mechanical Control Process (TMCP) technology and fine microstructure control technology. Recently, technology that combines AI to find the optimal alloy ratio that captures both strength and toughness (flexibility) has been established. In addition, by package-developing the material and welding consumables as a single set from the beginning, we eliminated the trial and error of having to return to the starting point due to mismatching later, thereby dramatically shortening the overall development period.

Lee Jae-ik: Due to national security and diplomatic sensitivity, all technologies from design to operation in marine defense steel development are managed under strict security. Technology development is mainly carried out as national projects led by the Defense Acquisition Program Administration (DAPA), and the achievements belong to national assets. When a customer requests the development of general-purpose technology, development proceeds in the form of a “Joint Development Project (JDP).”

The most representative case is the “development of fatigue design technology for high-strength steel welded joints” project conducted in 2019 with Hanwha Ocean (formerly Daewoo Shipbuilding & Marine Engineering) and the Korean Register (KR). The design was initially carried out by applying design technology transferred from Germany’s HDW, but we eventually pursued localization. Since then, the three organizations have cooperated to secure localized design technology. In the future, when localized welding materials and welding solutions are applied, it is expected that a self-production foundation for high-performance large submarines will be established.

Lee Jin-woo: POSCO develops next-generation naval materials by establishing an “Early Supplier Involvement (ESI) framework,” collaborating closely from the initial design stage with the special ship business divisions of the two major heavy industries, which are key communication channels for defense agencies. The KR certification of the newly developed materials was also achieved through collaboration with the Special Ship Business Division of HD Hyundai Heavy Industries and communication with defense agencies. Defense steel has the difficult challenge of simultaneously satisfying complex conflicting conditions such as protective performance, weldability, and on-site assembly alignment, beyond simple high strength. Therefore, during the collaboration process, we closely exchange opinions on manufacturing technology, component feasibility, special protective performance verification methods, and final specification (Spec-in).

This field-oriented, close technical exchange (Spec-in) allowed us to reflect the “reality of the field” early on, which is easy to miss in the laboratory, thereby compensating for the limitations of the laboratory unit early. Consequently, it is becoming a core competitiveness that overcomes the structural limitations unique to defense R&D, which usually takes more than 5 to 10 years, and enables actual naval application within a short period. POSCO proactively shared the operational concepts of weapon systems, coordinated required performance, and led the “simultaneous evolution of material and structural design.” This is a symbolic case showing why the current collaboration system is so important.

Lee Jin-woo: POSCO has established itself as a core foundation of the domestic shipbuilding and naval industries by proving global top-tier quality and mass production capability in the field of heavy plates for hull structures. In the field of next-generation special steel, we are continuing strategic challenges to surpass advanced military nations such as the US and Germany, which still lead in some areas. To this end, rather than simply chasing technology, we are pursuing a strategy to build “POSCO’s unique independent development model” where “material development, manufacturing technology, and vessel design” move like a single organic body by establishing a “close joint research system” with national defense research institutes and special ship design departments of shipyards. We believe that this value chain-integrated collaborative ecosystem will be the most powerful core competitiveness for POSCO to leap forward as a first mover leading the paradigm of next-generation naval material technology in the future.

▲ Conceptual rendering of a submarine. (Image source: my posco)

Lee Jae-ik: Analyzing the aspects of modern warfare, such as the recent war in Ukraine, the paradigm of future submarine steel technology can be summarized as “expansion of unmanned systems” and “extreme stealth” such as stealth performance. To apply to unmanned drones that will disperse the risks of manned submarines, a higher level of high-strength steel is essential, and neighboring countries like Japan are also secretly continuing to improve material performance. In response to this, Korea must also move toward developing “ultra-high-strength steel” that withstands deeper seas, larger hulls to increase weapon payload, and “high-strength non-magnetic steel” that fundamentally blocks the enemy’s magnetic detection in shallow waters. Ultimately, we believe that the high-functional special steel equivalent to or surpassing that of neighboring countries, and the advancement of welding and processing technologies to perfectly implement it, are the clear future directions we must preoccupy.

Lee Jae-ik: Ultra-high-strength steel, which completes the “stealthiness” that is the life of a submarine, has doubled in strength compared to 50 years ago, turning what was once a “dream material” into reality. The important point is that these cutting-edge defense technologies will expand to civilian industries in the future, such as lightweighting ships and reducing carbon emissions, serving as a solid foundation to lead the upcoming low-carbon, high-strength steel era. I will make sure POSCO plays a leading role in that.

Lee Jin-woo: I believe that material innovation has true value when applied in the field, rather than remaining as an achievement in the laboratory. POSCO has turned that value into reality through close collaboration with partners such as shipyards and research institutes, as well as research, production, quality, and marketing. Going forward, we will continue to enhance the competitiveness of next-generation naval materials based on accumulated technology and execution capability. I want to responsibly contribute to laying the foundation for Korea’s defense material technology and securing global competitiveness.

POSCO Investment makes its first overseas CVC investment in the low-carbon steel sector

On April 28, POSCO announced the signing of a joint development agreement with Electra of the United States to develop low-carbon ironmaking technology.

Founded in Colorado in 2020, Electra possesses proprietary technology that produces solid iron by removing impurities from iron ore through electrochemical reactions. The company is currently constructing a pilot plant with an annual capacity of 500 tons, aiming for operation within this year.

Through this agreement, the two companies plan to combine POSCO’s direct reduction technology with Electra’s low-carbon ironmaking system to jointly verify technical and economic feasibility for commercial production.

“POSCO brings deep experience in steelmaking, production technology and process development,” said Sandeep Nijhawan, Electra’s co‑founder and chief executive officer. “We’re building for the long term, and this partnership helps us scale thoughtfully as we bring clean iron to more customers.”

Eom Kyeong-geun, Head of POSCO Technical Research Laboratories, explained, “This partnership through the joint development agreement aims for strategic synergy between POSCO’s proprietary direct reduction and engineering technologies and Electra’s innovative electrochemical process.”

On the same day, POSCO Investment also announced a CVC investment agreement with Electra.

Kim Keun-hwan, President of POSCO Investment, stated, “This investment marks our first overseas strategic CVC investment in the decarbonized steel sector. It holds special significance as a climate-tech investment in preparation for the era of decarbonization.”

▲ POSCO and POSCO Investment sign a joint development and investment agreement with Electra to collaborate on technical validation for commercial production. (From left) Eom Kyeong-geun, Head of POSCO Technical Research Laboratories; Sandeep Nijhawan, CEO of Electra; and Kim Keun-hwan, President of POSCO Investment.

Providing integrated solutions that encompass procurement, sourcing, contracting, and risk management between headquarters and overseas subsidiaries

POSCO Group has established an Integrated Procurement Center in Shanghai, China, and has officially commenced its operations.

The opening ceremony, held on April 14, was attended by Lee, Yu-kyung, Head of Corporate Procurement Division; Lee, Seung-gi, Head of Plant, Equipment and Materials Procurement Office; and Lee, Won-chul, Representative of POSCO China (POSCO HOLDINGS). They were joined by representatives from 13 key local suppliers, including Ouyeel, Baowu Resources, and Sinosteel, as well as Lee, Do-an, Consul General of the Republic of Korea in Shanghai.

The establishment of this Integrated Procurement Center is a preemptive measure to respond agilely to the rapidly changing global supply chain environment.

China has been recognized as a core procurement hub where high-performing suppliers continue to grow. By establishing the global Integrated Procurement Center in Shanghai, POSCO Group plans to strengthen cooperation with excellent local suppliers and thereby enhance its global supply chain competitiveness.

The Integrated Procurement Center will also serve as a platform connecting the headquarters with overseas subsidiaries. Moving beyond simple purchasing functions, it is characterized by providing integrated solutions that encompass sourcing, contracting, and risk management.

Through this, the group plans to build a robust supply chain by linking its global network—including the Pohang and Gwangyang Steelworks in Korea as well as operations in Indonesia, Vietnam, and Argentina—and proactively propose the introduction of new products and technologies.

Lee, Yu-kyung, Head of Corporate Procurement Division, stated on that day, “The Integrated Procurement Center is a significant milestone that will elevate POSCO’s global procurement competitiveness to the next level. Through close cooperation with excellent local suppliers, we will secure cost competitiveness and build a robust supply chain to support the sustainable growth of POSCO Group.”

▲ The POSCO China Integrated Procurement Center held an opening ceremony in Shanghai, China, on April 14 and officially commenced operations.

CES 2026, the world’s largest technology trade show, has come to a close—and this year, one theme stood out above all others: robots. From humanoids and quadrupeds to sports and healthcare applications, robotics was everywhere on the show floor, signaling that the era of Physical AI—where AI and robotics come together in the real world—is quickly taking shape.

With Jae-bum Park, Senior Researcher at POSCO Research Institute, we look at what CES 2026 revealed about the future of robotics and where POSCO Group’s strengths could create new opportunities in this fast-growing industry.

Powering the Energy Transition: Robots Were Everywhere at CES 2026

At this year’s CES, robots were impossible to miss. Even in booths hosted by companies not traditionally associated with robotics, robot-related technologies appeared throughout the exhibition. The message was clear: AI-powered robots are moving beyond demonstrations and entering everyday life and industrial environments.

One of the most talked-about exhibits was Atlas, the humanoid robot presented by Boston Dynamics, Hyundai Motor Group’s robotics affiliate. Equipped with 56 degrees of freedom (DoF), Atlas demonstrated highly flexible movement and the ability to handle heavy-duty tasks involving loads of more than 50 kilograms—offering a glimpse of its potential in real industrial settings.

The exhibition also introduced a collaboration case involving POSCO and Boston Dynamics. On screen, Spot, Boston Dynamics’ quadruped robot, was shown moving through high-temperature facilities at a POSCO steelworks. In a noisy and heat-intensive environment, Spot was able to detect gas leaks and carry out precise inspections of equipment and infrastructure. The scene offered a compelling look at how robots are evolving from crowd-pleasing exhibits into reliable co-workers on industrial sites.

Another exhibit that drew attention came from Korean company Bodyfriend, which showcased a massage chair designed to feel almost like wearing a robotic suit. Its wearable AI healthcare robot, with independently moving arms and legs, attracted strong interest for its ability to analyze and stretch the user’s joints.

Robots were also making an impact in sports. Table tennis robots and combat robots once again proved popular with visitors, while sports robots introduced by Chinese companies such as Unitree and others showed just how far the technology has advanced. Some were able to analyze an opponent’s movements and track the trajectory of a ball in real time, providing highly detailed coaching.

Degrees of Freedom: What Makes Robot Movement More Sophisticated

As CES 2026 made clear, robot movement is becoming increasingly refined as technology advances. One term that many robotics companies use when discussing precision and flexibility is DoF, or Degree of Freedom. In simple terms, DoF refers to the number of joint axes a robot can move or control.

Generally speaking, the higher the DoF, the more independently controllable joints a robot has. This is particularly important for humanoid robots, which are expected to move in ways that resemble the human body. Industrial robot arms used in automated manufacturing processes typically have around 6 DoF, while humanoid robots usually range from 30 to 60 DoF. With 56 DoF, Boston Dynamics’ Atlas is close to the level required to mimic full-body human joint movement.

That said, increasing DoF also means adding more components such as motors, reducers, and sensors. In other words, the more sophisticated the movement, the higher the production cost. That is why robotics companies carefully design and allocate DoF based on each robot’s purpose and application.

Why Actuators Matter

An actuator is the drive unit that physically moves a robot’s joints. It can be understood as a complete joint system that combines a motor, reducer, sensor, and control circuit.

A motor on its own produces rotational motion. But for a robot arm to extend in a straight line or bend with precision, rotational movement alone is not enough. By integrating gears and electronic controls, an actuator enables more complex forms of motion, including both rotational and linear movement. If a motor is like a muscle cell, an actuator is the complete muscular joint that allows a limb to move in a controlled way.

For a humanoid robot with 56 DoF, roughly 56 precision actuators are needed.

Why Hyper NO Matters in the Age of Robotics

Electrical steel is also a critical material in motor manufacturing, accounting for roughly 20% to 30% of total motor production cost. This is especially important in robot motors, which must generate high output despite their compact size. In many cases, the performance of the electrical steel used inside the motor directly affects the motor’s overall efficiency and output.

To achieve better performance, the steel sheet must be made as thin as possible. If it is too thick, eddy currents* can form inside the material, causing energy loss in the form of heat.

*Eddy currents are swirling electric currents generated by electromagnetic induction when the magnetic field around a conductor changes rapidly.

POSCO’s high-performance electrical steel, Hyper NO, is designed to maximize magnetic performance even at extremely thin, paper-like thicknesses. The thinner electrical steel becomes, the more difficult it is to manufacture. In fact, only about five to six steelmakers worldwide, including POSCO, are capable of stably mass-producing electrical steel at the Hyper NO level. That makes it a strategic material with high technological barriers to entry—and an increasingly important one in the era of robotics and electrification.

Energy and Materials Will Help Power the Humanoid Robot Era

No matter how advanced a robot’s movement may be, it cannot function properly without enough energy. Today, humanoid robots typically operate continuously for only about two to four hours, making battery technology one of the biggest limiting factors in the industry.

At CES 2026, swappable battery systems emerged as a notable trend aimed at addressing that limitation. Boston Dynamics’ Atlas, for example, is known to operate continuously for around four hours, and it is even equipped with a function that allows it to replace its own battery when power runs low.

Tesla CEO Elon Musk recently predicted that there could be 10 billion humanoid robots within 25 years. If production reaches that scale, demand for actuators would rise into the hundreds of billions, making growth in demand for high-performance electrical steel almost inevitable. Once replacement demand is taken into account, the number of batteries required could also reach into the tens of billions.

This would also drive a sharp increase in demand for lithium, one of the key raw materials used in batteries. From this perspective, POSCO Group’s high-performance electrical steel technology and lithium assets are likely to draw growing attention as the robotics market continues to expand.

As robotics moves closer to real-world adoption, the future of the industry will depend not only on software and AI, but also on the materials and energy technologies that make advanced movement possible. In that future, POSCO Group is well positioned to play an important role.

Comprehensive review of cooperation with local steelmakers, stable material supply for Korean companies operating locally, and global expansion strategies for energy business

Chairman In-hwa Chang will preside over the Southeast Asia regional strategy meeting in Singapore on the 25th to review the complete localization execution strategies for the steel business.

This meeting was convened to strengthen regional business competitiveness and accelerate overseas growth strategies by establishing a complete localization operational system for overseas steel subsidiaries, amid growing uncertainties in the external business environment such as intensified global protectionism and slowing demand.

Chairman Chang, together with heads of key subsidiaries in the region, will review this year’s business plans and safety management policies, and focus discussions on the direction and execution tasks for advancing the supply chain of overseas subsidiaries.

In particular, the meeting will concretize execution plans for overseas growth strategies encompassing both steel and energy businesses, including:

• Expanding cooperation with local steelmakers in the region
• Establishing a stable material supply system for Korean companies operating locally
• Creating synergies between subsidiaries
• Expanding regional logistics hubs and improving operational efficiency
• Reviewing key issues of the Singapore LNG trading subsidiary established last year

Southeast Asia is a strategic market with high growth potential in downstream industries such as automobiles, home appliances, and construction. POSCO Group plans to systematically promote tailored growth strategies for each region by building a complete localization supply chain system based on its global business network.

POSCO Group has established production, processing, and distribution systems in the Southeast Asia region centered on key local subsidiaries, including PT. Krakatau POSCO in Indonesia, POSCO Yamato Vina, POSCO-Vietnam, POSCO-VST in Vietnam, POSCO-TCS and POSCO-Thainox in Thailand, and POSCO-Malaysia in Malaysia. Based on this, the Group is pursuing customer-focused sales strategies and expanding high value-added products, while continuously strengthening integrated regional competitiveness from raw material procurement to steel production and sales.

Meanwhile, Chairman Chang emphasized at the first group management meeting of the year in January, “We must materialize the fruits of future growth investments based on execution capabilities in times of crisis.” The Southeast Asia regional strategy meeting is part of efforts to further enhance the execution of overseas growth strategies in line with this management policy.

Highly rated for HyREX (hydrogen reduction steelmaking) technology and stakeholder communication.

POSCO Holdings has been named a “Top Performer” after ranking 4th globally in the Just Transition Benchmark assessed by the World Benchmarking Alliance (WBA), a global sustainability evaluation organization.

The WBA is a non-profit foundation launched at the 2018 UN General Assembly. It selects 2,000 most influential companies each year to evaluate their contributions to the UN Sustainable Development Goals (SDGs). This year’s the 2,000 most influential companies list includes 50 Korean companies, including POSCO Holdings.

In this assessment, POSCO Holdings ranked 4th out of over 1,600 global companies in the Just Transition Benchmark, while simultaneously securing 1st place both globally and in Korea within the Steel and Mining sector. The company also demonstrated its ESG leadership in the Nature Benchmark, ranking 87th globally, 16th in the Steel and Mining sector, and 1st in Korea.

The recognition as a “Top Performer” in the Just Transition is a direct result of the company’s efforts to reduce carbon emissions through its “HyREX” (hydrogen reduction steelmaking) technology and its successful communication with stakeholders. POSCO Holdings scored 75 out of 100 in the Just Transition Benchmark, placing it in the top five global companies.

In recognition of these achievements, POSCO Holdings attended the WBA event held during the World Economic Forum in Davos, Switzerland, where it shared sustainability cases with other top-tier global companies. The company further strengthened international cooperation by discussing decarbonization alternatives.

▲POSCO Holdings ranked 4th globally in the WBA’s Just Transition Benchmark and was named a Top Performer. (Source: WBA Website).

POSCO Holdings received high ratings from various global ESG rating agencies last year. In the assessment published by MSCI (Morgan Stanley Capital International), the company maintained an overall grade A for three consecutive years. Additionally, it received a risk score of 23.3 (medium risk) from Sustainalytics, placing its management capabilities in the top 4% of global steelmakers.

POSCO Group produces the core steel materials required to drive the global shift toward decarbonization. Through high-performance steel products and tailored solutions, the Group enhances safety, efficiency, and durability across industries including oil and gas, power generation, and renewable energy, contributing to the sustainable growth of the global energy sector. Here, we take a closer look at POSCO Group’s key steel products that are shaping the future of energy infrastructure.

Powering the Energy Transition with POSCO Group’s High-Performance Steel

The global energy landscape is undergoing a profound transformation. While technologies such as renewable energy, hydrogen, LNG, and CCUS continue to advance in pursuit of carbon reduction, it is advanced materials that ultimately enable these innovations to become reality. POSCO Group is supporting the advancement of next-generation energy infrastructure by providing steel engineered to perform under extreme environments and demanding conditions. From PosMAC, a high-corrosion-resistant alloy-coated steel used in renewable energy infrastructure, to steel forming the foundation of hydrogen pipeline systems, high-manganese steel recognized as a key material for liquefied hydrogen storage tanks, and LT-FH36, a core steel for LCO₂ carriers, POSCO’s high-performance steel products are applied across a wide range of energy transition industries, each tailored to specific application requirements.

Strengthening ESS Safety with PosMAC: A High-Corrosion-Resistant Alloy-Coated Steel

▲ PosMAC is used as a material for ESS battery cases developed by LG Energy Solution.

As renewable energy expands and power efficiency becomes increasingly important, demand for energy storage systems (ESS) continues to rise. Because ESS must store electricity safely and reliably over long periods, corrosion-resistant materials are essential. POSCO’s high-corrosion-resistant alloy-coated steel, PosMAC, is widely used in ESS battery enclosures, ensuring long-term stability and durability.

PosMAC offers more than five times the corrosion resistance of conventional galvanized steel, maintaining reliable performance even in coastal, high-humidity, and high-salinity environments. This durability helps reduce carbon emissions and overall lifecycle costs. As a result, PosMAC is extensively applied across renewable energy infrastructure, including wind turbine tower components, offshore wind structures, and solar module mounting systems. By extending equipment lifespans and reducing maintenance requirements, PosMAC plays a key role in driving the growth of sustainable energy.

Beyond ESS battery enclosures, PosMAC is expanding into a wider range of components, including racks and Battery Protection Unit (BPU) cases. Through close collaboration with customers, POSCO continues to enhance the product’s reliability and application range, reinforcing PosMAC’s position as a core material in the renewable energy industry.

Steel for Hydrogen Pipelines: The Foundation of Hydrogen Infrastructure

▲ Model of hydrogen pipeline steel exhibited at the POSCO Group booth at the 2025 International Climate Industry Expo.

Hydrogen is a cornerstone of future clean energy systems, requiring uncompromising safety throughout its entire value chain—from production and storage to transportation. In particular, pipelines transporting high-pressure gaseous hydrogen must resist hydrogen embrittlement* while maintaining reliable performance under extreme conditions.

*Hydrogen embrittlement: A phenomenon in which hydrogen penetrates a material, significantly reducing the ductility and toughness of the metal.

POSCO’s steel for hydrogen pipelines was designed to meet these stringent requirements. By replacing imported seamless pipes previously used for hydrogen transport, POSCO has enabled domestic production while offering strong cost competitiveness, supplying the product at approximately 70% of the cost of imported alternatives. The steel provides sufficient strength and toughness to withstand impact at temperatures as low as –45°C, not only in the pipe body (base material) but also at welded joints. After rigorous testing by international certification bodies, it has been confirmed to meet hydrogen pipeline performance standards, earning official recognition for its safety and reliability.

By 2025, POSCO plans to introduce high-strength materials compliant with API X70 standards for use in high-pressure environments of up to 100 bar. Demonstration and verification testing will be conducted in collaboration with Korea Gas Corporation (KOGAS), Korea Gas Safety Corporation (KGS), Korea Research Institute of Standards and Science (KRISS), and domestic steel pipe manufacturers.

*API (American Petroleum Institute): An organization that establishes international standards for pipelines and steel products used in the oil and gas industry.

Challenging –253°C: High-Manganese Steel for Liquefied Hydrogen Storage Tanks

▲ Model of high-manganese steel liquefied hydrogen storage tank exhibited at the POSCO Group booth at the 2025 International Climate Industry Expo.

Liquefied hydrogen (LH₂) is drawing global attention as a core technology for hydrogen transportation and storage in the hydrogen economy. Stored and transported at an ultra-cryogenic temperature of –253°C, liquefied hydrogen places significantly higher demands on storage tank materials than liquefied natural gas (LNG), which is handled at approximately –163°C. Against this backdrop, POSCO’s high-manganese steel is recognized as a key material capable of maintaining stability under such extreme conditions.

Independently developed by POSCO as the first of its kind in the world, high-manganese steel contains more than 22% manganese (Mn). It offers outstanding performance at cryogenic temperatures while offering a unique combination of high strength, excellent wear resistance, and non-magnetic properties that minimize electromagnetic effects. Its yield strength exceeds 335 MPa—approximately twice that of conventional stainless steel—while high elongation ensures excellent formability. In addition, relatively low manufacturing costs* contribute to its economic competitiveness. As a result, high-manganese steel is widely used in LNG infrastructure, including storage tanks, carriers, pipelines, and terminals.

*Manganese used in high-manganese steel is abundant worldwide and relatively inexpensive.

▲ Inside view of Tank No. 7 at Gwangyang LNG Terminal 2. High-manganese steel has been applied to the inner tanks of Units 5 and 6, and it is planned to be applied to Units 7 and 8 to be constructed in the future.

Over the past decade, POSCO’s high-manganese steel has proven its reliability through certifications from leading global classification and certification bodies. In 2022, the International Maritime Organization (IMO) formally adopted international technical standards governing its application, allowing the material to be used in cryogenic cargo and fuel tanks without separate flag-state approval. In 2024, it was further registered under standards applicable to both LNG and ammonia cargo and fuel tanks.

Building on its extensive experience in LNG infrastructure, POSCO is working to improve the performance of high-manganese steel so that it can reliably withstand impact even at –253°C. Going forward, the company plans to conduct demonstration projects and feasibility assessments through the fabrication of liquefied hydrogen storage tanks in collaboration with customers, aiming to secure both safety and economic viability for future hydrogen infrastructure.

Applied to the World’s Largest 22,000㎥ Vessels: Steel for LCO₂ Carriers

▲ AI virtual image of a liquefied carbon dioxide (LCO2) carrier.

Liquefied carbon dioxide (LCO₂) carriers are specialized vessels designed to safely store and transport carbon dioxide captured through CCUS processes after it has been cooled and compressed into liquid form. As the carbon capture and storage (CCS) industry continues to expand, the need for materials that support safer and more efficient vessel operations is becoming increasingly critical.

Unlike LNG and ammonia, which can be transported in liquid form under low-temperature conditions alone, carbon dioxide must be transported under both low temperature and controlled pressure. Scaling up liquefied carbon dioxide storage tanks therefore requires advanced steelmaking technologies.

POSCO’s LT-FH36 steel for LCO₂ carriers is engineered to maintain stable performance at temperatures as low as –60°C, reflecting the design conditions of low-pressure LCO₂ tanks. It can be applied in thicknesses of up to 50 mm and provides a yield strength exceeding 355 MPa. Even after post-weld heat treatment (PWHT), the steel maintains stable mechanical properties, ensuring long-term reliability in environments with elevated risks of corrosion and structural failure.

LT-FH36 is the world’s first steel to receive certification for use in large-scale liquefied carbon dioxide transport tanks. In 2023, at the international maritime exhibition Nor-Shipping, Lloyd’s Register (LR), a globally recognized British classification society, awarded POSCO official certification for steel used in large-scale LCO₂ carriers.

▲ The world’s largest 22,000㎥ liquefied carbon dioxide (LCO₂) carrier currently under construction at HD Hyundai Mipo. It uses POSCO’s LT-FH36 steel.(Photo source: HD Hyundai Heavy Industries)

LT-FH36 is currently applied to the world’s largest 22,000m³-class liquefied carbon dioxide carriers. In anticipation of the industry’s shift toward ultra-large storage tanks to improve transport efficiency, POSCO has also become the first in the world to complete the development and certification of LT-FH51, a higher-yield-strength steel grade. Over the longer term, the company plans to introduce even stronger grades, such as LT-FH70, further strengthening the safety and efficiency of next-generation LCO₂ carriers.

From PosMAC and steel for hydrogen pipelines to high-manganese steel and LT-FH36, POSCO Group’s independently developed high-performance steel products are delivering greater safety, efficiency, and sustainability across the energy industry. POSCO Group will continue to strengthen its materials technologies to help shape the infrastructure of the future global energy landscape.

Recently, POSCO Holdings announced a large-scale lithium investment plan as a core strategy to realize its vision of “Materials for the Nation,” laying a critical foundation for its ambition to emerge as a global lithium player. The investments target equity stakes in lithium mines in Australia and mining rights to the Hombre Muerto salt lake in Argentina, enabling POSCO Holdings to secure stable lithium production capacity while strengthening its global competitiveness. In this article, we take an in-depth look at the strategic significance of these investments and POSCO Group’s long-term lithium business outlook, together with Senior Research Fellow Jae-bum Park of the POSCO Research Institute.

Lithium is currently the most widely used material in electric vehicle batteries, yet its strategic value continues to rise rapidly. Beyond electric vehicles, lithium-based batteries are increasingly essential across a wide range of industries, including artificial intelligence, drones, next-generation aircraft, and space exploration. They also play a critical role in Energy Storage Systems (ESS), which store electricity generated from renewable energy sources such as solar and wind power. As demand continues to expand across these sectors, global efforts to develop faster and more efficient next-generation batteries are accelerating. Once commercialized, these advanced batteries are expected to drive a significant increase in lithium demand beyond current levels. In this context, lithium has firmly established itself as one of the most closely watched and strategically important raw materials worldwide.

Against this backdrop, POSCO Holdings, following extensive deliberation, decided to move forward with a large-scale lithium investment to strengthen its competitiveness in future advanced materials businesses. The initiative comprises two key pillars: an equity investment in lithium mines in Australia and the acquisition of mining rights to the Hombre Muerto salt lake in Argentina. These investments reflect POSCO Holdings’ strong commitment to securing a stable supply of high-quality lithium resources and positioning itself as a global lithium company.

Globally, only around ten lithium mines are classified as Tier-1, a designation reserved for assets with exceptionally high ore grades. Most of these are concentrated in Western Australia. POSCO Holdings plans to acquire equity stakes in two such Tier-1 assets: the Wodgina mine and the Mt Marion mine.

▲ POSCO Holdings, through a joint venture intermediate holding company established with Australia’s Mineral Resources, holds a 30% stake in the Wodgina mine (left) and the Mt. Marion mine (right). (Right photo source: Mineral Resources website)

The Wodgina mine has officially confirmed reserves of approximately 6.5 million tonnes of lithium carbonate equivalent (LCE)*, the standard reference form for lithium used in battery materials. Lithium at Wodgina is produced in the form of spodumene concentrate, which undergoes beneficiation to increase lithium content. With spodumene grades reaching approximately 5.5%, the Wodgina mine is widely regarded as a top-tier lithium asset. The Mt Marion mine likewise holds around 2.1 million tonnes of LCE in reserves, with spodumene concentrate grades approaching 5%, and is therefore also recognized as a high-quality lithium resource.

*LCE (Lithium Carbonate Equivalent): a standardized measure expressing lithium content in terms of lithium carbonate.

Currently, Mineral Resources holds a 50% stake in each mine. POSCO Holdings plans to establish a jointly owned intermediate holding company with Mineral Resources and invest approximately USD 765 million (around KRW 1 trillion) to acquire a 30% stake in the holding company.

By securing equity stakes in the Wodgina and Mt Marion mines, POSCO Holdings expects to stably secure approximately 270,000 tonnes of lithium concentrate per year, reflecting planned production capacity expansions at both sites. This volume is sufficient to produce around 37,000 tonnes of lithium hydroxide—enough to supply batteries for approximately 860,000 electric vehicles. Both mines are capable of producing spodumene concentrate, meaning the investment is expected to generate revenue not only through concentrate sales, but also by securing a stable supply via long-term offtake agreements.

In hard-rock lithium operations, raw material costs account for a substantial portion of total production costs, making integration between mining and downstream processing a critical determinant of cost competitiveness. Even with optimized production processes, there are inherent limits to reducing raw material costs. Accordingly, this investment provides a strategic foundation for generating raw material sales revenue, mitigating exposure to price volatility, and improving overall operational efficiency across the value chain.

In addition to its Australian mine investments, POSCO Holdings plans to acquire additional mining rights at the Hombre Muerto salt lake in Argentina. In 2018, the company already secured mining rights covering approximately 25,000 hectares in the northern portion of the salt lake, which spans a total area of roughly 60,000 hectares. Hombre Muerto is widely regarded as one of the world’s highest-quality brine resources, characterized by high lithium concentrations and low impurity levels. In light of expectations for rapidly rising global lithium demand, POSCO Holdings decided to pursue the additional acquisition.

The newly acquired area is adjacent to POSCO Holdings’ lithium processing plant currently under construction. The mining rights are held by NRG Metal, the Argentine subsidiary of Canadian company Lithium South. POSCO Holdings plans to acquire a 100% stake for approximately KRW 100 billion, enabling operational synergies with its existing salt lake assets.

The newly acquired salt lake asset is estimated to contain approximately 1.58 million tonnes of LCE, with an average lithium concentration of 736 mg/L, and is considered a premium brine resource due to its low impurity levels. Because the asset is located within the same Hombre Muerto salt lake already operated by POSCO Holdings, the brine composition is highly similar. This allows the company to leverage existing extraction processes, local infrastructure, and operational experience, creating favorable conditions for producing lithium at a competitive cost.

In parallel, POSCO Holdings is developing Direct Lithium Extraction (DLE) technology, moving away from the conventional evaporation pond method that requires several years. DLE offers shorter processing times, higher recovery rates, reduced land requirements, and lower water and environmental impact, making it a promising next-generation lithium extraction technology. With the additional mining rights secured, POSCO Holdings will be able to expand its lithium carbonate production infrastructure. Once DLE technology is fully validated and commercialized, the company expects to achieve more economical and efficient lithium production.

▲Ombre Muerto lithium salt lake, Argentina.

POSCO Group has established a foundation to produce lithium hydroxide domestically starting in 2024 by securing a supply of spodumene mined in Australia. This strengthened cooperation has expanded into equity investments in Australian lithium mines and broader collaboration with leading Australian research institutions, reinforcing R&D capabilities in critical minerals such as lithium and rare earth elements.

▲ POSCO Holdings signed an MOU with the Australian Nuclear Science and Technology Organisation (ANSTO) on November 19 for critical minerals technology development. From left: Ki-soo Kim, POSCO Group CTO, and Oleh Nakone, Group Executive at ANSTO.

In May, POSCO Holdings became the first Korean company to establish a dedicated overseas resource research hub with the launch of the Australia Critical Minerals R&D Lab. In November, it signed an MOU with the Australian Nuclear Science and Technology Organisation (ANSTO), Australia’s leading government-affiliated research institute and a central hub for critical minerals R&D. Through this partnership, the two organizations plan to pursue joint research projects in refining technologies and advanced material characterization, while holding regular technical exchange forums to strengthen global technological competitiveness.

By securing premium lithium resources, POSCO Group is establishing a stable supply base that will enable it to compete with top-tier global lithium producers over the long term. Worldwide, 65 companies are preparing for lithium production. Based on projected 2025 output, the top five producers are Albemarle, Ganfeng Lithium, SQM, Rio Tinto, and Tianqi Lithium.

Their primary competitive advantage lies in ownership of large-scale, high-grade lithium resources. Through this investment, POSCO Holdings is expected to secure annual lithium production capacity of approximately 93,000 tonnes by 2026—exceeding the roughly 70,000 tonnes produced by Tianqi, currently ranked fifth globally. Once ramp-up is complete and production stabilizes, POSCO Group has a strong chance of entering the global top 10 lithium producers.

By securing both spodumene from hard-rock mines and lithium from salt lakes, POSCO Holdings is also well positioned to expand refining capacity as market demand grows. This allows consideration of investments not only in lithium hydroxide, but also lithium carbonate, reducing supply-demand risks while diversifying the supply chain. Going forward, POSCO Group will continue to closely monitor lithium market conditions and policy developments, adjusting investment scale and timing with flexibility.

The recent Australian mine investments and the additional acquisition of salt lake mining rights in Argentina clearly demonstrate that POSCO Holdings’ future growth strategy is progressing successfully—and that its blueprint for securing premium lithium resources is steadily being realized.

POSCO Holdings signed a memorandum of understanding (MOU) on November 19 with the Australian Nuclear Science and Technology Organisation (ANSTO), Australia’s leading nuclear science and technology agency, to initiate a formal joint research cooperation on the processing and refining of critical minerals.

▲ POSCO Holdings signed an MOU with the Australian Nuclear Science and Technology Organisation (ANSTO) on November 19 for critical minerals technology development. From left: Ki-soo Kim, POSCO Group CTO, and Oleh Nakone, Group Executive at ANSTO.

Founded in 1953, ANSTO is Australia’s premier government research organisation, with world-class achievements in nuclear science, radiation medicine, materials science, and environmental and mineral resources research. In particular, the ANSTO Minerals business unit has distinguished itself in the development and commercialisation of several refining technologies for critical and strategic minerals such as lithium and rare earth elements, in addition to its support to critical minerals project development in Australia. ANSTO is one of the pillars of the Australian Critical Minerals R&D Hub, a collaboration between ANSTO, Geoscience Australia and CSIRO.

The signing ceremony was held via video conference connecting ROK and Sydney, Australia, and was attended by Ki-soo Kim, Head of POSCO N.EX.T Hub and POSCO Group CTO, Oleh Nakone, Group Executive of Nuclear Medicine and Commercial at ANSTO, and other key representatives from both sides.

Under the agreement, POSCO Holdings and ANSTO will pursue various collaborative projects related to the development of innovative mid-stream and down-stream processing technologies for lithium, rare earths, and other critical minerals. The two parties will also strengthen joint research cooperation through regular technical exchange meetings.

POSCO Group is currently producing battery-grade lithium on a commercial scale from lithium-containing hardrock and brine feedstocks, while also conducting demonstrations of the next-generation of processing technologies, such as Direct Lithium Extraction (DLE) technology. In the rare earth sector, the Group is actively exploring commercialization and technology internalization through collaborations and MOUs with domestic and overseas research institutions. In May this year, POSCO established the Australia Critical Minerals R&D Laboratories, the first overseas resource-specialized research base set up by a Korean company in Australia.

Ki-soo Kim, POSCO Group CTO, stated:
“POSCO Group is expanding its business scope beyond steel into the critical minerals sector, driving sustainable technological innovation. Today’s cooperation with ANSTO will serve as an opportunity to further strengthen the technological competitiveness of POSCO Group’s critical minerals business. By combining POSCO Group’s business capabilities with ANSTO’s critical and strategic minerals processing expertise, we will take the lead in the global critical minerals supply chain.”

Oleh Nakone, Group Executive Nuclear Medicine and Commercial at ANSTO, said:
“Through this collaboration with the POSCO Group, we can achieve the necessary innovation to enable both Australia’s and the Republic of Korea’s energy transitions in a sustainable way and diversify the supply chains of the economically significant critical minerals that both our countries require. Our applied R&D cooperation will deliver tangible results in the critical minerals sector.”

POSCO Holdings plans to continue expanding its network with major Australian research institutions, thereby enhancing its R&D capabilities in lithium, rare earths, and other critical minerals, and further boosting its global technological competitiveness.