C21D 1/40
Direct resistance heating
C21D1/40 (Direct resistance heating) appears on 123 US grants and 171 published applications in this corpus.
Search patents in C21D- Granted patents
- 123
- Published applications
- 171
- Assignees
- 107
- Inventors
- 377
- Latest grant
- 4 Nov 2025
Filings by year
| Year | Granted patents | Published applications |
|---|---|---|
| 1976 | 2 | 0 |
| 1977 | 1 | 0 |
| 1978 | 2 | 0 |
| 1979 | 0 | 0 |
| 1980 | 0 | 0 |
| 1981 | 0 | 0 |
| 1982 | 1 | 0 |
| 1983 | 0 | 0 |
| 1984 | 1 | 0 |
| 1985 | 0 | 0 |
| 1986 | 0 | 0 |
| 1987 | 1 | 0 |
| 1988 | 0 | 0 |
| 1989 | 1 | 0 |
| 1990 | 1 | 0 |
| 1991 | 0 | 0 |
| 1992 | 0 | 0 |
| 1993 | 1 | 0 |
| 1994 | 1 | 0 |
| 1995 | 0 | 0 |
| 1996 | 0 | 0 |
| 1997 | 0 | 0 |
| 1998 | 1 | 0 |
| 1999 | 2 | 0 |
| 2000 | 3 | 0 |
| 2001 | 3 | 0 |
| 2002 | 1 | 1 |
| 2003 | 0 | 3 |
| 2004 | 1 | 2 |
| 2005 | 3 | 2 |
| 2006 | 2 | 1 |
| 2007 | 0 | 0 |
| 2008 | 1 | 2 |
| 2009 | 0 | 5 |
| 2010 | 1 | 6 |
| 2011 | 1 | 3 |
| 2012 | 1 | 8 |
| 2013 | 7 | 9 |
| 2014 | 7 | 18 |
| 2015 | 5 | 17 |
| 2016 | 7 | 9 |
| 2017 | 10 | 17 |
| 2018 | 9 | 14 |
| 2019 | 12 | 9 |
| 2020 | 11 | 6 |
| 2021 | 4 | 6 |
| 2022 | 3 | 10 |
| 2023 | 6 | 1 |
| 2024 | 6 | 10 |
| 2025 | 4 | 7 |
| 2026 | 0 | 5 |
By publication year. Applications have been published since 2001. 2026 runs to 8 Oct.
Recent patents
- Steel pipe for fuel injection pipe, and fuel injection pipe using same4 Nov 2025US 12,460,275 B2Nippon Steel Corporation
- Steel pipe for fuel injection pipe, and fuel injection pipe using same20 May 2025US 12,305,597 B2Nippon Steel Corporation
- Method for manufacturing an austenitic steel component and use of the component4 Mar 2025US 12,241,139 B2Outokumpu Oyj
- Apparatus and methods for the drying treatment of an inductor7 Jan 2025US 12,188,720 B2Danieli Automation S.P.A.
- Electrical heating apparatus8 Oct 2024US 12,109,603 B2Sumitomo Heavy Industries, Ltd.
- Method and device for welding components, which can be travelled upon, of a track by flash butt welding23 Jul 2026US 2026/0208283 A1Voestalpine Railway Systems GmbH
- Forming system2 Apr 2026US 2026/0091424 A1Sumitomo Heavy Industries, Ltd.
- Radiant tube heater and heat treatment furnace19 Mar 2026US 2026/0078461 A1Daido Steel Co., Ltd.
- Coil spring manufacturing method12 Feb 2026US 2026/0042138 A1NHK Spring Co., Ltd.
- Manufacturing method of stabilizer and stabilizer22 Jan 2026US 2026/0022432 A1NHK Spring Co., Ltd.
Most cited
By later US patents
- Sheet forming of metallic glass by rapid capacitor discharge46US 8,613,815 B2California Institute of Technology · 2013
- Apparatus and method for thermomechanically forming an aluminide part of a workpiece38US 7,117,707 B2Philip Morris USA Inc. · 2006
- Instant heating process with electric current application to the workpiece for high strength metal forming30US 6,463,779 B12002
- Method for partly reinforcing a workpiece28US 6,742,374 B22004
- Magnetic and mechanical properties of amorphous alloys by pulse high current23US 4,950,337 AChina Steel Corporation · 1990