Nippon Steel Bets €900 Million on a Hybrid Future for Košice

On June 2, 1965, the first blast furnace at the steelworks outside Košice produced its first iron. More than six decades later, the plant is preparing to add a fundamentally different steelmaking route. U. S. Steel Košice, now part of Nippon Steel’s global group, has approved an investment of about €900 million in a new electric arc furnace and a new air-separation unit. ^{[1] [3]}

The Slovak operation signed a grant agreement with the Slovak government on September 15. The package provides access to as much as €350 million from the EU Modernisation Fund: €310 million for the electric arc furnace and €40 million for the air-separation unit. The ASU is scheduled to start in 2029 and the EAF in 2030. The furnace is planned for roughly 1.6 million metric tons of annual production. ^[1]

A hybrid steelworks, not an overnight conversion

An electric arc furnace makes steel by using electrical energy to generate an intense arc that melts metallic feedstocks such as scrap and direct-reduced iron. A blast furnace starts farther upstream, reducing iron ore with carbon-rich coke and coal before the metal reaches the steelmaking stage. Carbon is not merely a fuel in that process; it is part of the chemistry, and CO₂ is therefore inherent in conventional ore reduction. Nippon Steel’s own carbon-neutrality materials describe that problem directly. ^{[10] [11]}

That makes EAFs attractive, but not simple. They require large amounts of electricity. Scrap and reduced-iron quality matter greatly when a producer is trying to make demanding grades. Electricity prices and the carbon intensity of the grid affect both economics and emissions. A large integrated mill also has decades of equipment downstream and upstream that cannot be redesigned as if it were a greenfield mini-mill.

Košice’s answer is a hybrid. In an employee Q&A published by the plant, the company says the current plan calls for one EAF operating with the existing blast-furnace route, a configuration it believes provides the best balance of flexibility and resilience while preserving future options. ^[4]

The company puts the CO₂ reduction at about 2.7 million tons a year

Nippon Steel’s September 16 release says the investment will produce a significant reduction in CO₂ emissions but does not publish a figure. A separate official employee Q&A from U. S. Steel Košice is more specific: the company says it expects the project to reduce CO₂ emissions by about 2.7 million metric tons per year from the current level. ^[4]

The same Q&A says the EAF itself is expected to consume roughly 0.72 TWh of electricity annually and that total plant electricity demand would be about 2.0 TWh a year. Those figures illustrate an important limit to the shorthand “electric steel equals green steel.” Electrification moves a large part of the energy burden from coal toward the power system. The carbon benefit then depends partly on how that electricity is generated. ^[4]

Slovakia’s Ministry of Finance has separately analyzed the implications for the national power system. Its Value for Money unit says the steelworks currently consumes about 1.5 TWh a year — more than 5% of Slovakia’s 2024 electricity consumption — and expects the mill to become one of the country’s largest electricity consumers as electrification increases demand and reduces self-generation from process gases. ^[5]

The less glamorous companion investment: an air-separation unit

The second major asset in the package is the new Air Separation Unit, or ASU — described as an oxygen plant in Nippon Steel’s Japanese release. It separates atmospheric gases to provide industrial oxygen and related gases required for steelmaking. Nippon Steel says the unit will support stable mill operations, improve energy efficiency and contribute to lower CO₂ emissions. It is scheduled to enter service a year before the EAF. ^[1]

Oxygen remains important in electric steelmaking. It is used to accelerate reactions in the molten bath, remove carbon and impurities and improve furnace productivity. The ASU therefore shows why a conversion is much more than purchasing one giant furnace: the plant’s gas systems, power supply, casting, finishing and logistics all have to be integrated around the new route.

A mill born as a Cold War industrial project

The Košice steelworks began as Východoslovenské železiarne, or East Slovakian Steelworks, under communist Czechoslovakia. Its foundation document was signed in April 1959, construction began in January 1960, and the first blast furnace came on line in June 1965. By 1966 the integrated metallurgical cycle was complete. ^[3]

After the political transformation of 1989, the enterprise moved from state ownership toward a joint-stock structure and privatization. VSŽ and United States Steel formed a joint venture in 1998. On November 24, 2000, U. S. Steel took over the Košice steelmaking business. ^[3]

For the next quarter-century, U. S. Steel Košice supplied flat products to automotive, electrical, packaging, energy and construction customers, especially across Central and Eastern Europe. Nippon Steel later cited the plant’s location, customer base, diverse flat-steel portfolio, skilled workforce and existing facilities as reasons to make Košice a core European operating hub. ^[2]

Košice reached Tokyo through Pittsburgh

Nippon Steel’s ownership of Košice came through one of the most closely watched steel transactions in recent history. Nippon Steel agreed to acquire U. S. Steel in December 2023. After a prolonged U.S. political and national-security battle, the transaction was completed on June 18, 2025. Nippon Steel’s later financial disclosure lists that date as the acquisition date and says it obtained 100% of U. S. Steel’s voting equity. ^{[8] [9]}

Košice remained legally under U. S. Steel after the transaction, but Nippon Steel decided this year to move the Slovak company into direct ownership. On October 1, 2026, U. S. Steel Košice is scheduled to become a direct Nippon Steel subsidiary and change its name to Nippon Steel Slovakia s.r.o., or NSSK. ^[2]

Nippon Steel’s rationale reaches beyond corporate housekeeping. It describes Europe as the world’s third-largest steel market after China and the United States, with strong demand for high-grade steel. It also argues that tariffs, safeguards and the Carbon Border Adjustment Mechanism increase the value of producing inside the region rather than merely exporting into it. ^[2]

The Slovak project fits a technology push already under way in Japan

Nippon Steel’s Carbon Neutral Vision 2050 does not bet on a single route. It identifies three major technical tracks: high-grade steel in large electric arc furnaces, hydrogen-based direct reduction, and hydrogen injection into blast furnaces. ^{[10] [11]}

In Japan, the company has already decided to build, expand or restart EAF capacity at Yawata, Hirohata and Shunan. At Yawata, construction began in April 2026 on what Nippon Steel calls a world-first integrated mass-production system for high-grade steel using a large EAF. The company’s challenge is not simply melting scrap; it is proving that very large electric furnaces can consistently make grades traditionally associated with integrated blast-furnace steelmaking. ^[10]

Nippon Steel has not said that Košice will duplicate the Japanese designs. But the connection matters. The company acquiring direct control of the Slovak plant is simultaneously spending heavily to master large-EAF process control, raw-material management and high-grade production at home.

Košice once planned two EAFs, not one

The 2026 decision is smaller and more flexible than an earlier decarbonization concept. Slovakia’s Ministry of Finance says the previous plan envisioned two electric arc furnaces plus direct casting and rolling, at an estimated cost of roughly €2 billion, with a projected 70% reduction in greenhouse-gas emissions. The steelworks had qualified for support under two aid schemes worth as much as €600 million, but binding contracts were not completed while uncertainty persisted around U. S. Steel’s ownership. ^{[5] [13]}

The project was then redesigned. The current version uses one EAF, drops the direct-casting-and-rolling component and keeps blast furnaces in a hybrid system. U. S. Steel Košice’s own Q&A says management prefers that configuration because it balances flexibility with resilience and preserves options for later development. ^[4]

Why Brussels is helping pay

The Modernisation Fund is financed from revenues generated by the EU Emissions Trading System and is designed to support lower-income EU member states as they modernize energy systems, improve efficiency and cut greenhouse-gas emissions. Member states select projects; the European Investment Bank, European Commission and the fund’s Investment Committee have defined roles in the approval and disbursement process. ^{[6] [7]}

For Košice, the grant agreement provides up to €310 million for the EAF and €40 million for the ASU. The maximum grant is equivalent to about 39% of the announced €900 million investment if compared arithmetically, but that does not mean 39% of every project cost is automatically reimbursed: eligibility, milestones and payment conditions are governed by the grant agreement.

The policy logic is not solely environmental. Steelmakers in the EU pay for greenhouse-gas emissions under the ETS, while free allocations are being reduced. The economics of a carbon-intensive blast-furnace operation therefore deteriorate as carbon costs rise unless emissions fall or products earn a premium. Decarbonization spending becomes part of the cost of remaining competitive inside Europe.

The employment promise — and the unanswered workforce question

A technology shift this large immediately raises questions about jobs. In its employee Q&A, Košice management says Nippon Steel plans to increase production and productivity without reducing employment and says the ownership transition should not have a negative employment impact. It also points to a coming wave of retirements and the need to transfer technical knowledge to younger workers. ^[4]

Those are company commitments, not a published 2030 staffing plan. The mix of work will change as the plant adds high-voltage electrical equipment and EAF operations while adjusting coke, blast-furnace and primary-process activity. Headcount and job content therefore need to be followed separately.

What €900 million says about Nippon Steel’s Europe strategy

The sequence is as important as the amount. Nippon Steel completed the U. S. Steel transaction in 2025, announced direct ownership of Košice in May 2026, and has now approved one of the plant’s biggest technological transitions just before the Slovak subsidiary is renamed. That is the behavior of an owner trying to turn an inherited European asset into a strategic operating base.

The difficult questions are still ahead: electricity cost, access to low-carbon power, scrap and reduced-iron quality, the division of production between EAF and blast furnace, and whether the new route can supply the high-grade mix Nippon Steel wants to expand in Europe.

Košice began its industrial life around the blast furnace. Nippon Steel is not extinguishing that route in 2030. Instead, it plans to place a 1.6-million-ton electric furnace beside it and run both. In a steel industry where technology, carbon policy and raw-material security are all changing at once, the most revealing part of this €900 million decision may be precisely what Nippon Steel chose not to do: it did not make an all-or-nothing bet.