C21C 5/52
Manufacture of steel in electric furnaces
Official title: Manufacture of steel in electric furnaces {(C21C5/005 takes precedence)}
C21C5/52 (Manufacture of steel in electric furnaces) appears on 1,045 US grants and 838 published applications in this corpus.
Search patents in C21C- Granted patents
- 1,045
- Published applications
- 838
- Assignees
- 538
- Inventors
- 2,182
- Latest grant
- 22 Sep 2026
Filings by year
| Year | Granted patents | Published applications |
|---|---|---|
| 1976 | 21 | 0 |
| 1977 | 13 | 0 |
| 1978 | 18 | 0 |
| 1979 | 12 | 0 |
| 1980 | 12 | 0 |
| 1981 | 6 | 0 |
| 1982 | 9 | 0 |
| 1983 | 12 | 0 |
| 1984 | 26 | 0 |
| 1985 | 20 | 0 |
| 1986 | 24 | 0 |
| 1987 | 30 | 0 |
| 1988 | 24 | 0 |
| 1989 | 20 | 0 |
| 1990 | 18 | 0 |
| 1991 | 10 | 0 |
| 1992 | 13 | 0 |
| 1993 | 21 | 0 |
| 1994 | 23 | 0 |
| 1995 | 27 | 0 |
| 1996 | 27 | 0 |
| 1997 | 16 | 0 |
| 1998 | 23 | 0 |
| 1999 | 32 | 0 |
| 2000 | 24 | 0 |
| 2001 | 18 | 6 |
| 2002 | 25 | 16 |
| 2003 | 21 | 21 |
| 2004 | 21 | 23 |
| 2005 | 12 | 18 |
| 2006 | 3 | 21 |
| 2007 | 10 | 30 |
| 2008 | 12 | 28 |
| 2009 | 10 | 32 |
| 2010 | 27 | 40 |
| 2011 | 32 | 43 |
| 2012 | 23 | 45 |
| 2013 | 27 | 34 |
| 2014 | 28 | 34 |
| 2015 | 23 | 41 |
| 2016 | 25 | 33 |
| 2017 | 26 | 28 |
| 2018 | 19 | 25 |
| 2019 | 23 | 16 |
| 2020 | 22 | 36 |
| 2021 | 19 | 43 |
| 2022 | 17 | 37 |
| 2023 | 20 | 38 |
| 2024 | 35 | 63 |
| 2025 | 37 | 50 |
| 2026 | 29 | 37 |
By publication year. Applications have been published since 2001. 2026 runs to 8 Oct.
Subgroups
Granted patents
- C21C 5/5211In an alternating current [ac] electric arc furnace350
- C21C 5/527Charging of the electric furnace220
- C21C 5/5229In a direct current [dc] electric arc furnace162
- C21C 2005/5288Measuring or sampling devicesIndexing code109
- C21C 5/54Processes yielding slags of special composition77
- C21C 5/5241In an inductively heated furnace73
- C21C 5/5264Manufacture of alloyed steels including ferro-alloys73
- C21C 5/5294General arrangement or layout of the electric melt shop73
Recent patents
- Direct current electric arc furnace22 Sep 2026US 12,742,218 B2Masercata Oy
- High-carbon biogenic reagents and uses thereof1 Sep 2026US 12,723,211 B2Carbon Technology Holdings, LLC
- Temperature sensors28 Jul 2026US 12,693,171 B2Iowa State University Research Foundation, Inc.
- High-carbon biogenic reagents and uses thereof14 Jul 2026US 12,680,044 B2Carbon Technology Holdings, LLC
- High-carbon biogenic reagents and uses thereof7 Jul 2026US 12,674,108 B2Carbon Technology Holdings, LLC
- Method for melting iron source1 Oct 2026US 2026/0297697 A1Nippon Steel Corporation
- Novel process for the smelting of a metalliferous feedstock material yielding reduced carbon emissions1 Oct 2026US 2026/0297698 A1Metix (Proprietary) Limited
- Production and preparation method of carburized gear shaft bars by means of converter process24 Sep 2026US 2026/0286458 A1Bengang Steel Plates Co., Ltd.
- Systematic carbon emissions reduction method for whole process of production and casting3 Sep 2026US 2026/0258513 A1Jiqing Low Carbon Technology (Qinhuangdao) Co., Ltd.
- Composition of charcoal for use in production of steel, process of foaming slag in the production of steel in electric arc furnaces and use of a composition of charcoal3 Sep 2026US 2026/0258517 A1Vallourec SoluçõEs Tubulares Do Brasil S.A.
Most cited
By later US patents
- Scrap melter and impeller113US 6,723,276 B12004
- Adjustable momentum self-cooled oxy/fuel burner for heating in high temperature environments110US 5,199,866 AAir Products and Chemicals, Inc. · 1993
- Destruction of toxic chemicals100US 4,574,714 AUnited States Steel Corporation · 1986
- Destruction of toxic organic chemicals93US 4,602,574 AUnited States Steel Corporation · 1986
- Process and apparatus for melting a furnace charge87US 5,166,950 AL'Air Liquide, Societe Anonyme pour Etude et l'Exploitation des Procedes · 1992