C21D 1/72
During chemical change of surfaces
Official title: during chemical change of surfaces
C21D1/72 (During chemical change of surfaces) appears on 40 US grants and 41 published applications in this corpus.
Search patents in C21D- Granted patents
- 40
- Published applications
- 41
- Assignees
- 45
- Inventors
- 141
- Latest grant
- 16 Sep 2025
Filings by year
| Year | Granted patents | Published applications |
|---|---|---|
| 1976 | 1 | 0 |
| 1977 | 0 | 0 |
| 1978 | 1 | 0 |
| 1979 | 0 | 0 |
| 1980 | 1 | 0 |
| 1981 | 1 | 0 |
| 1982 | 0 | 0 |
| 1983 | 0 | 0 |
| 1984 | 0 | 0 |
| 1985 | 0 | 0 |
| 1986 | 0 | 0 |
| 1987 | 1 | 0 |
| 1988 | 2 | 0 |
| 1989 | 2 | 0 |
| 1990 | 0 | 0 |
| 1991 | 1 | 0 |
| 1992 | 0 | 0 |
| 1993 | 0 | 0 |
| 1994 | 1 | 0 |
| 1995 | 0 | 0 |
| 1996 | 0 | 0 |
| 1997 | 0 | 0 |
| 1998 | 1 | 0 |
| 1999 | 1 | 0 |
| 2000 | 0 | 0 |
| 2001 | 0 | 0 |
| 2002 | 3 | 0 |
| 2003 | 0 | 0 |
| 2004 | 1 | 0 |
| 2005 | 0 | 2 |
| 2006 | 0 | 1 |
| 2007 | 1 | 0 |
| 2008 | 1 | 1 |
| 2009 | 0 | 1 |
| 2010 | 0 | 1 |
| 2011 | 0 | 3 |
| 2012 | 1 | 3 |
| 2013 | 1 | 3 |
| 2014 | 0 | 6 |
| 2015 | 1 | 3 |
| 2016 | 2 | 2 |
| 2017 | 5 | 1 |
| 2018 | 2 | 2 |
| 2019 | 0 | 3 |
| 2020 | 1 | 1 |
| 2021 | 2 | 1 |
| 2022 | 1 | 4 |
| 2023 | 1 | 2 |
| 2024 | 2 | 1 |
| 2025 | 2 | 0 |
By publication year. Applications have been published since 2001.
Recent patents
- Preparation method of glassless grain-oriented silicon steel and product thereof16 Sep 2025US 12,416,059 B2Shougang Zhixin Electromagnetic Materials (Qian'an) Co., Ltd.
- Method for producing grain oriented electrical steel sheet15 Jul 2025US 12,359,274 B2Nippon Steel Corporation
- Fabrication method for a component having magnetic and non-magnetic dual phases12 Mar 2024US 11,926,880 B2General Electric Company
- Protective surface on stainless steel2 Jan 2024US 11,859,291 B2NOVA Chemicals (International) S.A.
- Grain-oriented electrical steel sheet and method for manufacturing same31 Jan 2023US 11,566,302 B2Jfe Steel Corporation
- Method for producing an oxidation protection coating at least in regions on a component of a thermal gas turbine29 Aug 2024US 2024/0287634 A1MTU Aero Engines AG
- Ni-based alloy material26 Oct 2023US 2023/0340644 A1NV Bekaert SA
- Annealing separator for oriented electrical steel sheet, oriented electrical steel sheet, and manufacturing method of oriented electrical steel sheet9 Feb 2023US 2023/0042915 A1Posco
- Preparation method of glassless grain-oriented silicon steel and product thereof17 Nov 2022US 2022/0364197 A1Beijing Shougang Co., Ltd.
- Hydrophilic stainless steel and method for manufacturing same3 Nov 2022US 2022/0349062 A1Iucf-Hyu (Industry-University Cooperation Foundation Hanyang University)
Most cited
By later US patents
- Surface on a stainless steel matrix23US 6,824,883 B1NOVA Chemicals (International) S.A. · 2004
- Method of producing grain-oriented silicon steel sheets having substantially no glass film12US 4,255,205 AKawasaki Steel Corporation · 1981
- Method for protecting from hardening a selected region of a steel structure12US 4,664,722 AHughes Tool Company - USA · 1987
- Steel-tooth bit with improved toughness11US 6,374,704 B1Baker Hughes Incorporated · 2002
- Process of treating a stainless steel matrix11US 6,436,202 B1NOVA Chemicals (International) S.A. · 2002