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IPC Subgroup
C21B 9/06

Linings

Introduced: September 1968

Last revised: January 2006

Full Title

Stoves for heating the blast in blast furnaces > Brick hot-blast stoves > Linings

Classification Context

Section:
CHEMISTRY; METALLURGY
Class:
METALLURGY OF IRON
Subclass:
MANUFACTURE OF IRON OR STEEL

Filing statistics

IPC C21B 9/06 belongs to the parent subclass C21B, which recorded 31,098 patent applications worldwide between 2013 and 2023. Annual filings grew from 2,313 in 2013 to 3,647 in 2023 (+58%), peaking at 3,970 applications in 2022. The most active applicants in class C21 are JFE STEEL (7,470 applications), POSCO (POHANG IRON AND STEEL COMPANY) (4,615 applications) and JFE STEEL (4,538 applications).

Source: EPO PATSTAT, worldwide filings

Top Applicants

Top 10 applicants by patent filingsfor class C21, 2013–2023, worldwide · Source: EPO PATSTAT

  1. JFE STEEL JP 7,470
  2. POSCO (POHANG IRON AND STEEL COMPANY) KR 4,615
  3. JFE STEEL 4,538
  4. NIPPON STEEL CORPORATION JP 4,536
  5. ARCELORMITTAL LU 2,597
  6. NSSMC (NIPPON STEEL & SUMITOMO METAL) JP 2,241
  7. ANGANG STEEL COMPANY 2,126
  8. NSSMC (NIPPON STEEL & SUMITOMO METAL) 1,783
  9. BAOSHAN IRON & STEEL COMPANY 1,620
  10. HYUNDAI STEEL COMPANY KR 1,545