Electric Arc Furnace Patents: Top Companies & Filing Trends 2026
- Filings nearly tripled in three years — +207% between 2021 (27) and 2024 (83), the last year the data can treat as complete.
- Leadership is real but not locked in — the top 5 assignees hold 16.9% of all 1,908 records and the top 10 hold 27.5%, leaving a long tail of single- and few-filing entrants.
- Claim density is uneven across the furnace — C21C steelmaking classes cover 51.0% of records while ceramics/refractory filings (C04B) sit at just 3.9%.
Filing growth compares 2021 (27 records) with 2024 (83) — a three-year span. 2024 is the most recent year we treat as complete: publication lags filing by roughly 18 months, so 2025 onwards are still filling in and any growth rate that ends there would understate the field. Top-5 share is the combined record count of the five largest assignees divided by all 1,908 records in scope (CR5), not by the ranked leaders only.
What this landscape covers
Electric arc furnace melting sits at the intersection of scrap metallurgy, high-current electrical control and refractory engineering. The search behind this page pairs core furnace terms — electric arc furnace, steel scrap melting, graphite electrode regulation — with the operating problems that actually drive filings: flicker generation, foaming slag, hot heel practice, electrode consumption, scrap preheating and tap-to-tap cycle time. That combination pulls in control-system patents alongside metallurgical process claims, which is why the technology composition spans steelmaking, furnace hardware and electric heating circuits rather than one narrow class.
The scope covers 1,908 published records with priority or publication activity from 2015 through the July 2026 data cut-off. Filing activity is credited by publication year, so the two most recent years are still filling in as later filings publish.
Let an AI agent run this analysis on your own technology
Pick a task. Every answer cites the patents behind it.
Filing trend and technology composition
Two views of the same 1,908-record dataset: how filing volume has moved year over year, and how those records split across the IPC subclasses that describe furnace hardware, steelmaking process and electrical control.
Growth phase, not a plateau
Publications rose from 49 in 2017 to a peak of 83 in 2024, with the 2021→2024 span alone up 207%. The 2025 and 2026 figures (down to 9 by 2026) reflect publication lag rather than a real slowdown — filings made in the last 18 months have not finished publishing yet.
Steelmaking process dominates, refractory chemistry is thin
C21C steelmaking accounts for 51.0% of the 1,908 records, and F27D furnace details/accessories for 37.1% — the two together describe most of what gets filed. C04B ceramics and refractories sits at only 3.9%, and C01B non-metallic elements at 4.5%, both far below what the furnace's thermal and chemical demands would suggest is available to claim.
Shares are the percentage of the 1,908 records in scope. A patent can carry several IPC classes, so the shares add up to more than 100%.
Go deeper on Electric Arc Furnace Melting with Eureka
This page is one run against one query. Ask Eureka your own question about electric arc furnace melting and every answer comes back with the patent numbers behind it.
Try EurekaMost-cited records and a representative filing
US5539768A — Electric arc furnace electrode consumption analyzer
An electric arc furnace includes at least one electrode projecting into a furnace vessel for containing a charge to be heated and electrode support structure for moving the electrode in a direction along a path towards and away from the charge. An improvement to the electric arc furnace comprises a sensor for detecting the position of the electrode support structure from an initial position. A processor calculates one of a support structure travel distance from the initial position and a rate of electrode consumption. An alarm signal is generated in response to at least one of the travel distance and the rate of electrode consumption being at least equal to a respective predetermined threshold.Filed by International Steel Group Inc.; granted 1996-07-23.
| # | Publication no. | Patent title | Citations |
|---|---|---|---|
| 1 | US20110127702A1 | Dynamic control of lance utilizing counterflow fluidic techniques | 310 |
| 2 | US5400358A | Continuous scrap preheating | 109 |
| 3 | US5714113A | Apparatus for electric steelmaking | 108 |
| 4 | US6004504A | Method and apparatus for controlling bath level and measurement of bath characteristics | 99 |
| 5 | US4439491A | Oxidation retardant for graphite | 98 |
| 6 | US20030075843A1 | Multi-purpose, multi-oxy-fuel, power burner/injector/oxygen lance device | 95 |
| 7 | US5611838A | Process for producing an iron melt | 95 |
| 8 | US5599375A | Method for electric steelmaking | 80 |
| 9 | US6372010B1 | Method for metal melting, refining and processing | 76 |
| 10 | US4575856A | Iron free self baking electrode | 68 |
Ranked by citation count within the searched corpus; older filings accumulate citations for longer, so treat this as a signal of influence rather than of current technical importance.
Each row carries its publication number; clicking a row searches Eureka by that number.
Put your own technology through the same analysis
Eureka on the web
When you want the answer in the next five minutes.
The agent works the prompt against patents and technical literature, citing every source.
Run your analysis now →MCP server & REST API
When it has to run inside your own pipeline.
Patent search, landscape analysis and assignee resolution as MCP tools. Drop them into any agent framework, or call REST directly.
Browse MCP servers →What the numbers mean for a filing decision
Three read-throughs from the concentration, growth and citation figures above, aimed at where a new filing would actually land.
Leadership is present but not exclusive
The top 5 assignees combined hold 16.9% of all 1,908 records and the top 10 hold 27.5%. That leaves roughly three-quarters of the dataset spread across a long tail of assignees, including many with only a handful of filings — the space is open to new entrants who can show a genuine process improvement.
Filing activity is still climbing, not cooling
Publication counts nearly tripled between 2021 and 2024, the last year the data can be treated as complete. The apparent drop-off in 2025 and 2026 is a publication-lag artefact, not a real decline — filings from those years are still working through the pipeline.
Steelmaking process claims are crowded; refractory chemistry is not
Just over half of all records touch C21C steelmaking process claims, and over a third touch F27D furnace hardware. Ceramics and refractory materials (C04B) and non-metallic inorganic compounds (C01B) sit in single digits, despite refractory wear and slag chemistry being persistent operating problems in every EAF shop.
Eureka can read the same corpus for gaps instead of for coverage: under-claimed branches adjacent to electric arc furnace melting, with the prior art for and against each one.
| Assignee | Co-assignee | Shared families |
|---|---|---|
| ABB (Schweiz) AG | Tenova S.p.A. | 15 |
| CISDI Engineering Co., Ltd. | CISDI Technology Research Center Co., Ltd. | 6 |
| L'Air Liquide, Société Anonyme pour l'Étude et l'Exploitation des Procédés Georges Claude | GRANT MICHAEL | 5 |
| L'Air Liquide, Société Anonyme pour l'Étude et l'Exploitation des Procédés Georges Claude | Air Liquide USA LLC | 3 |
| Tenova S.p.A. (Techint International) | MEMOLI FRANCESCO | 3 |
| Tenova S.p.A. (Techint International) | BRIONI OSVALDO | 3 |
| Tenova S.p.A. (Techint International) | BIANCHI FERRI MAURO | 3 |
| L'Air Liquide, Société Anonyme pour l'Étude et l'Exploitation des Procédés Georges Claude | LAURENT JACKY | 2 |
Only 10 co-assignee pairs appear in the dataset, and the strongest pairing accounts for 15 shared records — most assignees in this field file independently rather than through joint ventures or shared R&D vehicles.
Who is filing, and where the gate sits
The leader holds 87 records; fifth place holds 50 and tenth place 35 — a steep drop from the top but no single company controls the field. Recent-year momentum for several previously active assignees has flattened to zero in the latest published year, consistent with the publication-lag effect rather than a real pullback.
A clear but not dominant top filer
The leading assignee's 87 records put it well ahead of fifth place at 50, but its recent-year count has dropped to zero — a pattern shared by several other established filers and best read as publication lag rather than withdrawal from the field.
A competitive second tier
Positions five through ten sit in a 35-to-50-record band, close enough together that a handful of new filings could reorder the middle of the ranking. This tier is where equipment suppliers, gas and materials specialists, and engineering contractors compete on furnace control and consumables claims.
Joint filings are the exception
With only 10 co-assignee pairs identified and the strongest at 15 shared records, most patenting activity here is done solo. Where pairing does happen, it tends to link an engineering-technology arm with its research-centre affiliate rather than cross-company alliances.
| Assignee | Recent year | YoY |
|---|---|---|
| GrafTech International Holdings Inc. | 0 | — |
| ChemTreat Inc. | 0 | -100% |
| SMS Group GmbH | 0 | — |
| L'Air Liquide, Société Anonyme pour l'Étude et l'Exploitation des Procédés Georges Claude | 0 | — |
| Midrex Technologies Inc. | 0 | — |
| ABB (Schweiz) AG | 0 | -100% |
| CISDI Engineering Co., Ltd. | 0 | — |
| Voestalpine AG | 0 | — |
Where to take this next
The dataset points to a field that is still growing and only moderately concentrated at the top, with clear gaps in refractory and slag-chemistry claims relative to steelmaking process and furnace hardware.
Map the white space before filing
Under-claimed branches like refractory wear-life monitoring and foaming-slag chemistry sit next to dense steelmaking and furnace-hardware classes — worth checking against a fresh claim before assuming the space is occupied.
Explore the white space in EurekaWatch the mid-tier, not just the leader
The 35-to-50-record band five through ten is close enough that new filings could shift the ranking; tracking this tier can surface emerging competitors earlier than watching the leader alone.
Track assignee momentum in EurekaCommon questions about electric arc furnace melting patents
Within this dataset of 1,908 records, one assignee leads with 87 records, well ahead of fifth place at 50 and tenth place at 35. The top 5 assignees combined hold 16.9% of all records and the top 10 hold 27.5%, which means the majority of filings come from a long tail of companies with smaller portfolios. No single company controls the field, so competitive tracking needs to cover the mid-tier as well as the leader.
It is growing. Publications rose from 49 in 2017 to a peak of 83 in 2024, and the 2021-to-2024 span alone shows +207% growth. The apparent decline in 2025 and 2026 is a publication-lag artefact: patent publications typically trail filing by around 18 months, so the most recent one to two years always look understated in any trend chart. Treat 2024 as the last complete year for growth comparisons.
Steelmaking process claims (IPC class C21C) appear in 51.0% of the 1,908 records, and furnace details and accessories (F27D) in 37.1% — together these describe the bulk of filing activity. Electric heating and control circuits (H05B) cover 24.9%. By contrast, ceramics and refractories (C04B) sit at just 3.9% and non-metallic inorganic compounds (C01B) at 4.5%, both thin relative to how central refractory wear and slag chemistry are to furnace operation.
US5539768A, assigned to International Steel Group Inc. and granted in 1996, covers an electric arc furnace fitted with a sensor that tracks electrode support structure position from an initial reference point, a processor that calculates travel distance or consumption rate from that position data, and an alarm triggered when either value crosses a preset threshold. It blocks designs that combine position sensing on the electrode support structure with threshold-based alarming for consumption rate. It does not by itself cover alternative sensing modalities (optical, current-based, or acoustic) or consumption estimation methods that skip physical position sensing altogether, which is where design-around work typically starts.
The United States leads receiving offices with 425 filings in this dataset, followed by the European Patent Office at 273 and Canada at 146. WIPO's PCT route accounts for 145 filings, with India at 129 and Japan at 125. This spread indicates the technology is filed broadly across major industrial and steel-producing jurisdictions rather than concentrated in one region, which matters for freedom-to-operate checks that need to cover more than a single office.
Research Electric Arc Furnace Melting in depth with Eureka
Go past this page: query the whole electric arc furnace melting corpus yourself, in your own scope.
Every answer comes back with patent numbers you can open.
Disclaimer. This page is generated from Patsnap Eureka data drawn from a limited snapshot of global patent and scientific-literature records, and is provided for general information and reference only.
Patent data carries inherent limitations: recent filings (typically the most recent 18–24 months) are under-counted due to standard publication lag; counts may be reported at either a patent-family or a patent-record basis and are not always directly comparable; classification, applicant-name, and citation data may contain errors, duplicates, or omissions; and the underlying search query defines and constrains the scope shown. As a result, the analysis may be incomplete or inaccurate and may not reflect the full technology landscape.
Nothing on this page constitutes an exhaustive prior-art, novelty, freedom-to-operate, or validity search, nor does it constitute legal, financial, investment, or professional advice, and it should not be relied upon as such. Any patent, commercial, or strategic decision should be verified independently and reviewed with qualified patent, legal, and domain professionals. Patsnap makes no warranties, express or implied, as to the accuracy, completeness, or fitness for any particular purpose of the information presented.
Machine translation. Assignee and organisation names originally recorded in Chinese, Japanese or Korean have been rendered into English by an AI translation step so that the tables stay readable. These renderings are best-effort and may not match a company’s registered English name; the original name is what the underlying patent record carries, and it is what any Eureka query launched from this page uses.