- All sections
- C - Chemistrymetallurgy
- C21D - Modifying the physical structure of ferrous metalsgeneral devices for heat treatment of ferrous or non-ferrous metals or alloysmaking metal malleable, e.g. by decarburisation or tempering
- C21D 1/25 - Hardening, combined with annealing between 300 °C and 600 °C, i.e. heat refining ("Vergüten")
Patent holdings for IPC class C21D 1/25
Total number of patents in this class: 281
10-year publication summary
|
25
|
30
|
22
|
30
|
21
|
13
|
22
|
18
|
20
|
5
|
| 2016 | 2017 | 2018 | 2019 | 2020 | 2021 | 2022 | 2023 | 2024 | 2025 |
Principal owners for this class
| Owner |
All patents
|
This class
|
|---|---|---|
| JFE Steel Corporation | 6916 |
34 |
| ArcelorMittal | 2319 |
27 |
| Nippon Steel Corporation | 6334 |
18 |
| United States Steel Corporation | 174 |
8 |
| Hitachi Metals, Ltd. | 1973 |
6 |
| Baoshan Iron & Steel Co., Ltd. | 966 |
6 |
| ThyssenKrupp Steel Europe AG | 959 |
6 |
| Voestalpine Stahl GmbH | 359 |
6 |
| Daido Steel Co., Ltd. | 271 |
4 |
| Tata Steel Nederland Technology BV | 151 |
4 |
| Caterpillar Inc. | 9628 |
3 |
| Aubert & Duval | 112 |
3 |
| L.E. Jones Company, LLC | 18 |
3 |
| POSCO Co., Ltd. | 1571 |
3 |
| Rautaruukki Oyj | 146 |
3 |
| Uddeholms Aktiebolag | 195 |
3 |
| Robert Bosch GmbH | 42813 |
2 |
| Aisin AW Co., Ltd. | 2324 |
2 |
| Schaeffler Technologies AG & Co. KG | 9973 |
2 |
| NTN Corporation | 4970 |
2 |
| Other owners | 136 |