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CPC Subgroup
C21D 1/54

Determining when the hardening temperature has been reached by measurement of magnetic or electrical properties

Full Title

General methods or devices for heat treatment, e.g. annealing, hardening, quenching or tempering > Determining when the hardening temperature has been reached by measurement of magnetic or electrical properties

Top Applicants

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

  1. JFE STEEL JP 8,270
  2. NIPPON STEEL CORPORATION JP 5,222
  3. POSCO (POHANG IRON AND STEEL COMPANY) KR 4,824
  4. JFE STEEL 3,311
  5. ARCELORMITTAL LU 3,239
  6. NSSMC (NIPPON STEEL & SUMITOMO METAL) JP 2,659
  7. HYUNDAI STEEL COMPANY KR 1,492
  8. ANGANG STEEL COMPANY 1,318
  9. BAOSHAN IRON & STEEL COMPANY 1,233
  10. KOBE STEEL JP 1,228