- 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 6/04 - Hardening by cooling below 0° C
Patent holdings for IPC class C21D 6/04
Total number of patents in this class: 135
10-year publication summary
|
5
|
12
|
12
|
13
|
11
|
10
|
5
|
12
|
6
|
4
|
| 2017 | 2018 | 2019 | 2020 | 2021 | 2022 | 2023 | 2024 | 2025 | 2026 |
Principal owners for this class
| Owner |
All patents
|
This class
|
|---|---|---|
| Aubert & Duval | 114 |
10 |
| Daido Steel Co., Ltd. | 284 |
5 |
| Messer Group GmbH | 49 |
5 |
| Hitachi Metals, Ltd. | 1900 |
4 |
| ArcelorMittal | 2663 |
4 |
| CRS Holdings, Inc. | 29 |
4 |
| Salzgitter Flachstahl GmbH | 163 |
4 |
| CRS Holdings, LLC | 148 |
4 |
| Danmarks Tekniske Universitet | 1026 |
3 |
| Jiangsu University | 1166 |
3 |
| QuesTek Innovations LLC | 61 |
3 |
| Shinhokoku Material Corp. | 16 |
3 |
| SNECMA S.A. | 1146 |
2 |
| Hitachi, Ltd. | 16071 |
2 |
| Huawei Technologies Co., Ltd. | 123282 |
2 |
| NSK Ltd. | 2831 |
2 |
| Hilti Aktiengesellschaft | 3662 |
2 |
| Aktiebolaget SKF | 3126 |
2 |
| JFE Steel Corporation | 7508 |
2 |
| National Oilwell Varco, L.P. | 1698 |
2 |
| Other owners | 67 |