Iron & Steelmaking Patents: Who Leads, Where the Gaps Are 2026
- 23.1% of all 15,844 records sit with just five assignees, while a long tail files once or twice and drops out.
- Filing peaked in 2022 at 794 records and the leader's own filings fell 51% year-on-year in the latest tracked period.
- Steelmaking and alloy claims dominate at 32.9% and 23.0% of records respectively, while furnace-accessory and casting claims sit well below 15%.
Filing growth compares 2021 (700 records) with 2024 (536) — 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 15,844 records in scope (CR5), not by the ranked leaders only.
What this landscape covers
This dataset tracks 15,844 published records filed against molten metal processing, reduction furnaces, alloy composition and related iron and steelmaking claims between 2015 and the 2026 cut-off. The search string pairs core process terms — molten metal, reduction furnace, alloy impurity — against the broader steelmaking and alloy-metal vocabulary, so the corpus spans blast-furnace reduction, secondary steelmaking, alloy formulation and the furnace hardware that supports all three.
Filing is not evenly spread across the process chain. Steelmaking (C21C) and alloy composition (C22C) claims together outnumber furnace-accessory and casting claims by a wide margin, which says more about where applicants believe the differentiable IP sits than about where the engineering effort actually goes.
Filing trends and technology composition
Publication lags filing by roughly 18 months, so the most recent one or two years in any trend understate true filing activity — treat 2025 and 2026 as still filling in rather than as a real slowdown.
A 2022 peak followed by an incomplete decline
Filings rose from 517 in 2017 to a peak of 794 in 2022. Using the last fully comparable span, 2021's 700 records fell to 536 by 2024, a 23% drop — a real contraction in a mature filing area, not an artefact of publication lag, since both years are complete.
Steelmaking and alloy claims lead by a wide margin
C21C (steelmaking) covers 32.9% of records and C22C (alloys) 23.0%, each well ahead of blast-furnace iron production at 19.3%. Furnace hardware (F27D, F27B) and casting (B22D) each sit at or below 12.4%, suggesting hardware and process-equipment claims are comparatively less contested than composition and process-route claims.
Shares are the percentage of the 15,844 records in scope. A patent can carry several IPC classes, so the shares add up to more than 100%.
Go deeper on Iron & Steelmaking Patent Landscape with Eureka
This page is one run against one query. Ask Eureka your own question about iron & steelmaking patent landscape and every answer comes back with the patent numbers behind it.
Try EurekaA representative filing and how it reads
US20010025549A1 — Method of manufacturing molten metal iron
Filed by Midrex International, this record claims a rotary-hearth-furnace route: charging a carbonaceous reducing material with iron oxide, reducing it under heat to solid reduced iron, carburizing that solid iron with carbon from the reducing material to melt it, separating slag, and discharging molten metal iron for recovery, with a specified downward-inclined furnace surface.Filed 2001-10-04 — an early, frequently-referenced articulation of the rotary-hearth direct-reduction route still used as a reference point in later filings.
| # | Publication no. | Patent title | Citations |
|---|---|---|---|
| 1 | US20160045841A1 | New and improved system for processing various chemicals and materials | 860 |
| 2 | US5149680A | Platinum group metal alloy catalysts for hydrogenation of carboxylic acids and their anhydrides to alcohols a… | 490 |
| 3 | US20150143806A1 | Quintuple-Effect Generation Multi-Cycle Hybrid Renewable Energy System with Integrated Energy Provisioning, S… | 268 |
| 4 | US4985572A | Catalyzed hydrogenation of carboxylic acids and their anhydrides to alcohols and/or esters | 267 |
| 5 | WO2014153570A2 | New and improved system for processing various chemicals and materials | 219 |
| 6 | EP0285420A1 | The catalysed hydrogenation of carboxylic acids and their anhydrides to alcohols and/or esters | 195 |
| 7 | US4574714A | Destruction of toxic chemicals | 188 |
| 8 | US5322547A | Method for indirect chemical reduction of metals in waste | 182 |
| 9 | US3591362A | Composite metal powder | 182 |
| 10 | US5443572A | Apparatus and method for submerged injection of a feed composition into a molten metal bath | 174 |
Citation counts favour older records simply because they have had more time to be cited — read them as a signal of influence within this searched set, not as a ranking of current importance.
Each row carries its publication number; clicking a row searches Eureka by that number.
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Three patterns stand out once the ranking, the trend and the class shares are read together.
Filing sits with a small group, not one dominant player
The top 5 assignees combined hold 23.1% of all 15,844 records in scope, and the top 10 hold 32.4%. That is meaningful concentration but well short of a single-company lock — the leader's 1,203 records against a fifth-place figure of 392 shows a fast drop-off rather than a plateau.
The contraction is real, but check who is pulling back
Filing fell from 700 records in 2021 to 536 in 2024, a complete and comparable three-year span. Recent-year momentum data shows the leading assignee's own filings down 51% year-on-year in the latest tracked period, with several established filers down 56-82% — a broad pullback among incumbents, not just one company easing off.
Composition claims crowd out hardware claims
Steelmaking process claims (C21C, 32.9% of records) and alloy composition claims (C22C, 23.0%) are claimed far more densely than furnace and kiln hardware (F27B, 8.3%). Heavy claim density in process and composition space does not mean the underlying chemistry is settled — it means that space is where applicants have chosen to fight.
Eureka can read the same corpus for gaps instead of for coverage: under-claimed branches adjacent to iron & steelmaking patent landscape, with the prior art for and against each one.
Who is filing, and where the gate sits
The ranked leaders file across steelmaking, alloy and blast-furnace claims, with co-filing patterns pointing to close operating partnerships rather than open licensing.
A clear top filer with a fast drop-off behind it
The leading assignee holds 1,203 records against 392 at fifth place and 255 at tenth — a steep gradient rather than a plateau, which means the next tier of filers is contesting a much smaller pool of claim space than the leader itself.
Strongest pairs top out at 26 shared records
The strongest co-assignee pairs in this corpus each reach 26 shared records, consistent with integrated steelmakers filing jointly with affiliated research institutes or refractory suppliers rather than with competitors — a sign of vertically coordinated R&D, not open collaboration.
Established filers are pulling back at the same time
Every incumbent tracked for recent-year momentum shows a year-on-year decline, ranging from -17% to -82%, with one long-standing filer at zero for the latest year. That is a coordinated retreat across established filers, worth watching against 2025-2026 data once publication lag closes.
| Assignee | Recent year | YoY |
|---|---|---|
| POSCO | 20 | -51% |
| ArcelorMittal | 19 | -17% |
| JFE Steel Corporation | 4 | -56% |
| Nippon Steel Corporation | 3 | -70% |
| Carbon Technology Holdings LLC | 3 | -82% |
| Kawasaki Steel Corporation | 0 | — |
| Kobe Steel, Ltd. | 0 | — |
| Sumitomo Metal Industries, Ltd. | 0 | — |
Where to take this from here
The dataset points to specific next steps rather than a single conclusion.
Map the white space before filing
Furnace hardware and slag-recovery claims are thinner than the steelmaking and alloy core. A freedom-to-operate check focused on these under-claimed branches is likely to surface fewer blocking references than a search centred on core alloy composition.
Explore white space in EurekaTrack the incumbent pullback into 2025-2026
Every tracked incumbent shows a year-on-year decline, but publication lag means 2025 and 2026 figures will keep rising as filings publish. Re-run this trend once those years settle before concluding the field is shrinking.
Monitor filing trends in EurekaStudy the co-filing pairs for partnership models
The strongest co-assignee pairs suggest integrated filing between steelmakers and affiliated institutes or suppliers. Reviewing these pairs' claim scope can clarify how joint R&D is being protected versus licensed.
Review assignee relationships in EurekaCommon questions about this landscape
The leading assignee in this ranking holds 1,203 records, well ahead of the fifth-place filer at 392 and tenth place at 255. The top 5 assignees combined account for 23.1% of all 15,844 records in scope, and the top 10 for 32.4% — meaningful concentration, but the steep drop-off from first to fifth place shows no single company controls the field outright. The rest of the ranked leaders and a long tail of single- or few-filing entrants fill out the remainder.
Filing rose to a peak of 794 records in 2022 before falling; comparing the last two fully complete years, 2021's 700 records dropped to 536 in 2024, a 23% decline. That is a genuine contraction rather than a data artefact, because both years have had time to publish. Figures for 2025 and 2026 will look lower still, but that reflects the roughly 18-month publication lag rather than an actual further drop — they should not be read as confirming the trend until more time has passed.
Steelmaking process claims (IPC class C21C) appear in 32.9% of the 15,844 records, the largest single share, followed by alloy composition (C22C) at 23.0% and blast-furnace iron production (C21B) at 19.3%. Furnace hardware and casting classes each sit at or below 12.4% of records. Because a single record can carry multiple IPC classes, these shares add up to more than 100% and should be read individually against the full record count, not summed.
This Midrex filing claims a rotary-hearth-furnace method for producing molten metal iron: charging a carbonaceous reducing material with iron oxide, reducing it under heat into solid reduced iron, carburizing that iron with carbon from the reducing material to melt it, separating the slag produced during melting, and discharging molten metal iron through a furnace fitted with a specified downward-inclined surface. It is a process-and-apparatus claim tied to that specific furnace geometry and reduction sequence, filed in 2001, and it functions in this landscape as an early reference point for the rotary-hearth direct-reduction route rather than a blanket block on molten-iron production generally.
Furnace hardware and accessory classes (F27D, F27B) and casting (B22D) each carry noticeably lower claim density than steelmaking and alloy composition, sitting at or below 12.4% of the 15,844 records compared with 32.9% for C21C. Specific sub-areas worth a closer freedom-to-operate look include furnace refractory wear monitoring, slag-to-value-product recovery, low-carbon reducing-agent substitution and real-time alloy impurity sensing. These are process-adjacent rather than untouched, so any filing there should still run a targeted prior-art search rather than assume open space.
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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.