- 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 1/18 - HardeningQuenching with or without subsequent tempering
Patent holdings for IPC class C21D 1/18
Total number of patents in this class: 1923
10-year publication summary
|
163
|
151
|
161
|
196
|
153
|
137
|
147
|
187
|
264
|
92
|
| 2016 | 2017 | 2018 | 2019 | 2020 | 2021 | 2022 | 2023 | 2024 | 2025 |
Principal owners for this class
| Owner |
All patents
|
This class
|
|---|---|---|
| Nippon Steel Corporation | 6166 |
225 |
| JFE Steel Corporation | 6767 |
166 |
| ArcelorMittal | 2227 |
152 |
| Nippon Steel & Sumitomo Metal Corporation | 1988 |
63 |
| POSCO Co., Ltd. | 1395 |
62 |
| Kabushiki Kaisha Kobe Seiko Sho (Kobe Steel, Ltd.) | 2872 |
42 |
| ThyssenKrupp Steel Europe AG | 950 |
39 |
| NTN Corporation | 4974 |
38 |
| Baoshan Iron & Steel Co., Ltd. | 955 |
36 |
| Voestalpine Stahl GmbH | 353 |
34 |
| Nanjing Iron&Steel Co.,Ltd. | 161 |
20 |
| Caterpillar Inc. | 9472 |
18 |
| Hitachi Metals, Ltd. | 1990 |
16 |
| POSCO | 2189 |
16 |
| ThyssenKrupp AG | 3266 |
16 |
| GM Global Technology Operations LLC | 14879 |
13 |
| Jiangyin Xingcheng Special Steel Works Co., Ltd. | 61 |
13 |
| Voestalpine Metal Forming GmbH | 76 |
13 |
| Aktiebolaget SKF | 2921 |
11 |
| Tata Steel Ijmuiden B.V. | 304 |
10 |
| Other owners | 920 |