Inclusion Control Patents: Who Leads, Where the Gaps Are 2026
Inclusion Control and Steel Cleanliness Patents: Mapping the Filing Landscape
41.7% concentration. The top 5 of 94 ranked assignees account for 116 of 278 records in scope — a small group holding disproportionate ground in calcium treatment, reoxidation control and castability claims. Filings rose to a peak of 7 in 2021 before falling to 3 by 2024, a 57% decline over that three-year window. Treat 2025 and 2026 as incomplete rather than as a continuation of the decline, since publication typically lags filing by around 18 months.
- 1NUCOR CORP47
- 2NIPPON STEEL CORPORATION32
- 3KAWASAKI STEEL CORP14
- 4TATA STEEL IJMUIDEN BV13
- 5LG ELECTRONICS INC10
See the full inclusion control and steel cleanliness analysis in Eureka
- The complete ranking, not just the top five
- Every IPC branch with its share of the corpus
- The most-cited records, and where claim space is still thin
Common questions about this landscape
Who holds the most patents in inclusion control and steel cleanliness?
One assignee leads clearly with 47 of the 278 records in scope, well ahead of the fifth-placed company at 10 and the tenth at 6. The top 5 assignees together account for 41.7% of all records, and the top 10 for 54.7%. Beyond that, the ranking of 94 companies thins into a long tail of firms with only a handful of filings each, typical of refractory suppliers and ceramics makers filing around a shared casting problem.
Is patent filing in this field growing or slowing down?
Filings peaked at 7 in 2021 and fell to 3 by 2024, a 57% decline over that span. It would be a mistake to read the years after 2024 as continuing that fall, because patent publication typically lags filing by around 18 months, so the most recent years in any dataset are always undercounted. The honest read is that activity cooled from a 2021 high, with the true 2025-26 trend not yet visible.
Which technology areas see the most patent activity in steel cleanliness?
B22D, metal casting, appears in 56.5% of the 278 records, making it the dominant IPC subclass by a wide margin. C22C (alloys) follows at 42.8% and C21C (steelmaking) at 28.1%, while heat treatment (C21D) and rolling (B21B) trail well behind. Because records often carry multiple IPC codes, these percentages overlap rather than sum to a whole, but the ranking itself is a reliable guide to where claim density is heaviest.
Disclaimer. This analysis is based on Patsnap Eureka data drawn from a limited snapshot of global patent records and is provided for general information and reference only. Patent data carries inherent limitations — recent filings are under-counted because of publication lag, counts may be on a record or family basis, classification and applicant-name data may contain errors or duplicates, and the underlying search query defines the scope shown — so the analysis may be incomplete or inaccurate and may not reflect the full technology landscape.
Nothing here is an exhaustive prior-art, novelty, freedom-to-operate or validity search, nor does it constitute legal, financial or professional advice, and it should not be relied upon as such. Verify independently and review with qualified patent and legal professionals before acting on it.
Method: Filing trend and technology composition. Derived from a Patsnap search on Inclusion Control and Steel Cleanliness covering 2015–2026, data cut-off 2026-07-31. Counts reflect published records only and shift as new filings publish. Every share divides by all records in scope. Data: Patsnap Eureka. See the full landscape report.