Rebar Production and Quenching Patents: Who Leads, Trends 2026
- Five assignees account for all 24 records in scope. the ranking closes at 100.0% coverage with no long tail of unranked filers left outside it.
- Filing peaked in 2021 at 8 records, then fell to zero by 2024. a -100% swing over that three-year span that predates the reporting lag on 2025-2026 data.
- Heat treatment claims dominate: C21D appears in 83.3% of records. while alloy composition (C22C) sits at 62.5%, showing most activity clusters in processing rather than rolling geometry.
Filing growth compares 2021 (8 records) with 2024 (0) — 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 24 records in scope (CR5), not by the ranked leaders only.
What this landscape covers
This landscape tracks patent activity at the intersection of hot rolled and thermomechanically treated (TMT) rebar and the quenching and self-tempering processes that set its martensitic rim. The search combines process terms — martensitic rim thickness, water box design, microalloying reduction — with performance claims around weldability, rib geometry and seismic-grade property, capturing records where metallurgical process and product-in-use claims meet.
Coverage runs from 2015-01-01 through the 2026-07-31 data cut-off. Because publication typically lags filing by around 18 months, the most recent one to two years of the trend are understated and should not be read as a decline in real filing activity.
Filing trend and technology composition
Twenty-four published records sit in scope, spanning a filing peak in 2021 and a technology mix weighted heavily toward heat treatment over rolling mechanics.
Filing trend, 2017-2026
Filings rose from 2 records in 2017 to a peak of 8 in 2021, then fell to 0 by 2024 – a -100% swing over that three-year window. 2025 and 2026 figures are still filling in due to publication lag and should not be read as the field going quiet.
IPC subclass composition
C21D (heat treatment of metals) appears in 83.3% of the 24 records in scope, well ahead of C22C (alloys) at 62.5%. Rolling and drawing classes (B21B, B21C) each sit at 16.7%, and coating, tunnel-support and structural-component classes barely register – each record can carry more than one class, so these shares add to more than 100%.
Shares are the percentage of the 24 records in scope. A patent can carry several IPC classes, so the shares add up to more than 100%.
Go deeper on Rebar Production and Quenching with Eureka
This page is one run against one query. Ask Eureka your own question about rebar production and quenching and every answer comes back with the patent numbers behind it.
Try EurekaMost-cited records in this landscape
High Strength Seamless Steel Pipe for Machine Structure Use Superior in Toughness and Weldability, and Method of Production of The Same
A high strength seamless steel pipe for machine structure use, specified by a narrow compositional window (C, Mn, Ti, Nb, B, with optional Ni, Cr, Cu, Mo) and a metallurgical structure that is either a single phase of self-tempered martensite or a mixed phase of self-tempered martensite and lower bainite.Filed by Nippon Steel & Sumitomo Metal Corporation, published 2009-03-12.
View full filing| # | Publication no. | Patent title | Citations |
|---|---|---|---|
| 1 | EP2028284A1 | High-strength seamless steel pipe for mechanical structure which has excellent toughness and weldability, and… | 40 |
| 2 | US20090065102A1 | High Strength Seamless Steel Pipe for Machine Structure Use Superior in Toughness and Weldability, and Method… | 7 |
| 3 | IN201631011723A | Process for production of seismic resistant high strength fe500 s grade thermo mechanically treated (TMT) bar | 1 |
| 4 | IN201631004862A | An improved thermo-mechanically treated rebar with a rib configured through optimization of root radius and h… | 1 |
Citation counts reflect influence within the searched corpus and favour older filings; they are not a measure of current commercial importance.
Publication numbers are shown where the record carries one (4 of 4 rows); clicking a row searches Eureka by that number.
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The dataset is small and concentrated, which changes how it should be read: a handful of players cover the whole ranked field, and the composition skews toward process claims over product geometry.
No unranked long tail
All 24 records in scope trace to the five ranked assignees, with the leader alone accounting for 14 of them. There is no fragmented tail of single-filing entrants outside this ranking to watch for surprise entrants.
Peak passed, recent years still filling in
2021 was the peak filing year at 8 records; by 2024, the last year treatable as complete, filings had fallen to 0 – a -100% swing. Filings from 2025 onward are undercounted due to the roughly 18-month publication lag and should not be read as the field going cold.
Process claims dominate over geometry
C21D heat treatment claims appear in 83.3% of the 24 records, compared with 16.7% for metal rolling (B21B) and the same for extrusion and drawing (B21C). Most competitive pressure sits on quenching and tempering process claims, not on rib or rolling-tool geometry.
Eureka can read the same corpus for gaps instead of for coverage: under-claimed branches adjacent to rebar production and quenching, with the prior art for and against each one.
The assignee landscape
Five companies make up the entire ranked field for this search, led by one filer with 14 records against a fifth-place entrant holding a single record.
Furthest ahead on volume
The leading assignee holds 14 of the 24 records in scope, more than the remaining four ranked companies combined. Recent-year momentum for this filer sits at zero in the latest year, consistent with the broader post-2021 pullback in the trend.
A closed, fully covered ranking
The ranking is not a top-50 or top-100 cut – it is the entire set of assignees returned for this search, and together they cover all 24 records. There is no unranked long tail left to size up separately.
Uniform pullback across the field
Every ranked assignee shows zero filings in the latest year, mirroring the fall from the 2021 peak of 8 to 0 by 2024. This is a field-wide pattern rather than one company stepping back while others continue.
| Assignee | Recent year | YoY |
|---|---|---|
| ArcelorMittal | 0 | — |
| Nippon Steel Corporation | 0 | — |
| Steel Authority of India Ltd | 0 | — |
| Tata Steel Ltd | 0 | — |
Where to take this analysis
The ranked field is small enough to review claim-by-claim rather than by statistical sampling alone.
Map claims against the under-claimed branches
Rib geometry, water box design and coating-compatible surfaces show thin coverage next to the dominant heat-treatment classes – a focused claim search there can confirm whether the gap is real or just under-indexed by these search terms.
Explore white space in EurekaTrack the five ranked assignees for renewed filing
With every ranked assignee at zero in the latest year, a fresh filing from any of them would be a meaningful signal worth monitoring given the field's small size.
Set up assignee monitoring in EurekaCommon questions on rebar production and quenching patents
Within this dataset, one assignee leads with 14 of the 24 records in scope, well ahead of the other four ranked companies. Those five companies together account for 100.0% of all records returned by the search, meaning there is no significant unranked long tail of smaller filers to track separately. This concentration makes the field easier to monitor than a fragmented one, since a small number of portfolios cover essentially all relevant prior art.
Filing peaked in 2021 at 8 records and fell to 0 by 2024, a -100% change over that three-year span. However, 2025 and 2026 figures are still incomplete because publication typically lags filing by around 18 months, so it would be premature to call the field dormant based on the most recent years alone. The safest reading is that the post-2021 pullback is real through 2024, with more recent activity still emerging in the data.
Self-tempered martensite refers to the microstructure formed at the rebar's outer rim when it is quenched rapidly after hot rolling and then allowed to temper using residual heat from the still-hot core – a process central to thermomechanically treated (TMT) rebar. It is the mechanism behind the strength-toughness-weldability balance that seismic-grade rebar needs. Patent claims in this space concentrate heavily in the C21D heat treatment class, which appears in 83.3% of the 24 records analysed here, more than any other IPC subclass.
Relative to heat treatment (83.3% of records) and alloy composition (62.5%), classes covering coating and surface deposition, tunnel and mine support structures, and structural building components each appear in only about 4-8% of the 24 records in scope. Rib geometry and rolling-tool design (B21B, B21C) also sit lower, at 16.7% each. These thinner areas are worth a closer claim-level search before assuming they are genuinely open, since low coverage in this specific search does not rule out relevant prior art indexed under different terms.
US20090065102A1, filed by Nippon Steel & Sumitomo Metal Corporation, claims a high-strength seamless steel pipe with a tightly specified alloy composition and a metallurgical structure of self-tempered martensite, either alone or mixed with lower bainite. It is one of the more heavily cited records in this landscape, alongside its related filing EP2028284A1, reflecting its role as a foundational reference for self-tempering process claims. Anyone filing composition or heat-treatment claims for similar martensitic structures should review its specific elemental ranges closely, since overlapping composition windows are a common source of rejection.
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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.