- All sections
- C - Chemistry; metallurgy
- C21D - Modifying the physical structure of ferrous metals; general devices for heat treatment of ferrous or non-ferrous metals or alloys; making metal malleable, e.g. by decarburisation or tempering
- C21D 1/18 - Hardening; Quenching with or without subsequent tempering
Patent holdings for IPC class C21D 1/18
Total number of patents in this class: 1621
10-year publication summary
|
170
|
163
|
151
|
161
|
196
|
153
|
136
|
144
|
178
|
70
|
| 2015 | 2016 | 2017 | 2018 | 2019 | 2020 | 2021 | 2022 | 2023 | 2024 |
Principal owners for this class
| Owner |
All patents
|
This class
|
|---|---|---|
| Nippon Steel Corporation | 5649 |
180 |
| JFE Steel Corporation | 6067 |
139 |
| ArcelorMittal | 1887 |
99 |
| Nippon Steel & Sumitomo Metal Corporation | 1990 |
63 |
| POSCO Co., Ltd. | 1059 |
41 |
| Kabushiki Kaisha Kobe Seiko Sho (Kobe Steel, Ltd.) | 2865 |
38 |
| NTN Corporation | 5008 |
36 |
| ThyssenKrupp Steel Europe AG | 924 |
32 |
| Baoshan Iron & Steel Co., Ltd. | 832 |
30 |
| Voestalpine Stahl GmbH | 311 |
27 |
| Hitachi Metals, Ltd. | 2175 |
16 |
| Nanjing Iron&Steel Co.,Ltd. | 135 |
16 |
| Caterpillar Inc. | 8877 |
15 |
| POSCO | 2222 |
15 |
| ThyssenKrupp AG | 3086 |
15 |
| Jiangyin Xingcheng Special Steel Works Co., Ltd. | 58 |
13 |
| Aktiebolaget SKF | 2700 |
11 |
| GM Global Technology Operations LLC | 13620 |
10 |
| Kobe Steel, Ltd. | 912 |
10 |
| Tata Steel Ijmuiden B.V. | 283 |
10 |
| Other owners | 805 |