IPC Subgroup
C21D 3/04 Decarburising
Introduced: September 1968
Last revised: January 2006
Full Title
Diffusion processes for extraction of non-metals; Furnaces therefor > Extraction of non-metals > Decarburising
Classification Context
- Section:
- CHEMISTRY; METALLURGY
- Class:
- METALLURGY OF IRON
- Subclass:
- 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
Related Keywords
DECARBURISING iron and steel by diffusiondecarburising IRON by diffusion
Top Applicants
Top 10 applicants by patent filingsfor class C21, 2013–2023, worldwide · Source: EPO PATSTAT
- JFE STEEL JP 7,470
- POSCO (POHANG IRON AND STEEL COMPANY) KR 4,615
- JFE STEEL 4,538
- NIPPON STEEL CORPORATION JP 4,536
- ARCELORMITTAL LU 2,597
- NSSMC (NIPPON STEEL & SUMITOMO METAL) JP 2,241
- ANGANG STEEL COMPANY 2,126
- NSSMC (NIPPON STEEL & SUMITOMO METAL) 1,783
- BAOSHAN IRON & STEEL COMPANY 1,620
- HYUNDAI STEEL COMPANY KR 1,545