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US4668298A Expired / Lapsed US ⏱️ 0.0 years remaining

Coating composition for preventing high temperature oxidation for electrodes

Assignee: Mitsumaru Chemical and Synthetic Industrial Co Ltd
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Filing: 1986-06-16
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Granted: 1987-05-26
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Expires: 2006-06-16
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Abstract

Abstract The invention relates to a coating composition containing ceramic components, for preventing high temperature oxidation of graphite electrodes employed in electric furnace steelmaking. This ceramic composition consists of the following components: (a) 40-75% by weight of silicon carbide as a heat radiation component; (b) 15-40% by weight of a binding and heat radiation promoting component consisting of 3-20 parts by weight of silicon nitride, 5-20 parts by weight of salt of phosphorous-containing acid, 2-10 parts by weight of chromium oxide, 2-10 parts by weight of tantalum carbide, and 5-20 parts by weight of pulverous aluminum; (c) 10-35% by weight of an additive for improving the adhesion to the graphite electrode and increasing the binding strength between the coated layers, consisting of 1-10 parts by weight of aluminum oxide, 3-15 parts by weight of glass powder, 3-15 parts by weight of zirconium oxide, 1-10 parts by weight of silicon dioxide, 1-10 parts by weight of magnesium oxide, and 1-10 parts by weight of iron oxide; (d) 5-20% by weight of a metal powder consisting of 0-40 parts by weight of pulverous copper, 0-40 parts by weight of pulverous nickel, 0-40 parts by weight of pulverous stainless steel, 0-40 parts by weight of pulverous iron, and 0-40 parts by weight of pulverous tin; (e) 2-5% by weight of a sintering promoter mixture consisting of 10-30 parts by weight of silver carbonate, and 30-50 parts by weight of copper sulfate, and/or 30-50 parts by weight of iron sulfate; and (f) 3-7% by weight of a melting point lowering component consisting of 30-60 parts by weight of iron fluoride, and 40-70 parts by weight of copper fluoride.

Inventors

  • 👤 Kazutomi Funahashi
  • 👤 Koichi Yoshii
  • 👤 Yoichi Nakamura
  • 👤 Tatsumi Oshikiri
  • 👤 Hajime Kobayashi

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-02 17:54
CPC Classifications
B; B22; B22F; B22F9/00; H; H05; H05B; H05B7/00; H05B7/02; H05B7/06; H05B7/08; H05B7/085; H05B7/12

Claims Analysis

Total Claims: 4
Claim 1
Independent Claim 272 words
A coating composition for preventing the high temperature oxidation of steelmaking graphite electrodes, which comprises: (a) 40-75% by weight of silicon carbide as a heat radiation component; (b) 15-40% by weight of a binding and heat radiation promoting component consisting of 3-20 parts by weight of silicon nitride, 5-20 parts by weight of salt of phosphorous containing acid, 2-10 parts by weight of chromium oxide, 2-10 parts by weight of tantalum carbide, and 5-20 parts by weight of pulverous aluminum; (c) 10-35% by weight of an additive for improving the adhesion to the graphite electrode and increasing the binding strength between the coated layers, consisting of 1-10 parts by weight of aluminum oxide, 3-15 parts by weight of glass powder, 3-15 parts by weight of zirconium oxide, 1-10 parts by weight of silicon dioxide, 1-10 parts by weight of magnesium oxide, and 1-10 parts by weight of iron oxide; (d) 5-20% by weight of a metal powder consisting of 0-40 parts by weight of pulverous cooper, 0-40 parts by weight of pulverous nickel, 0-40 parts by weight of pulverous stainless steel - 40parts by weight of pulverous iron, and 0-40 parts by weight of pulverous tin; (e) 2-5% by weight of a sintering promoter mixture consisting of 10-30 parts by weight of silver carbonate, and 30-50 parts by weight of copper sulfate, and/or 30-50 parts by weight of iron sulfate; and (f) 3-7% by weight of a melting point lowering component consisting of 30-60 parts by weight of iron fluoride, and 40-70 parts by weight of copper fluoride; wherein the total of the above components (a)-(f) add up to 100% by weight.
Claim 2
Dependent Claim 272 words
A coating composition for preventing the high temperature oxidation of steelmaking graphite electrodes, which comprises: (a) 40-75% by weight of silicon carbide as a heat radiation component; (b) 15-40% by weight of a binding and heat radiation promoting component consisting of 3-20 parts by weight of silicon nitride, 5-20 parts by weight of salt of phosphorous containing acid, 2-10 parts by weight of chromium oxide, 2-10 parts by weight of tantalum carbide, and 5-20 parts by weight of pulverous aluminum; (c) 10-35% by weight of an additive for improving the adhesion to the graphite electrode and increasing the binding strength between the coated layers, consisting of 1-10 parts by weight of aluminum oxide, 3-15 parts by weight of glass powder, 3-15 parts by weight of zirconium oxide, 1-10 parts by weight of silicon dioxide, 1-10 parts by weight of magnesium oxide, and 1-10 parts by weight of iron oxide; (d) 5-20% by weight of a metal powder consisting of 0-40 parts by weight of pulverous cooper, 0-40 parts by weight of pulverous nickel, 0-40 parts by weight of pulverous stainless steel - 40parts by weight of pulverous iron, and 0-40 parts by weight of pulverous tin; (e) 2-5% by weight of a sintering promoter mixture consisting of 10-30 parts by weight of silver carbonate, and 30-50 parts by weight of copper sulfate, and/or 30-50 parts by weight of iron sulfate; and (f) 3-7% by weight of a melting point lowering component consisting of 30-60 parts by weight of iron fluoride, and 40-70 parts by weight of copper fluoride; wherein the total of the above components (a)-(f) add up to 100% by weight.
Claim 3
Dependent Claim 52 words
A coating composition according to claim 1, consisting of 40-65% by weight of the component (a), 15-35% by weight of the component (b), 10-18% by weight of the component (c), 6-18% by weight of the component (d), 2-5% by weight of the component (e) and 3-7% by weight of the component (f).
Claim 4
Dependent Claim 52 words
A coating composition according to claim 1 or 2, wherein the component (d) consists of 1-40 parts by weight of pulverous copper, 1-40 parts by weight of pulverous nickel, 0.40 parts by weight of pulverous stainless steel, 1-40 parts by weight of pulverous iron and 1-40 parts by weight of pulverous tin.

References Cited (Backward Citations)

US4185136A Cited
US4289538A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1990-05-25 1990-11-24 1991-05-26 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1994-05-25 1994-11-24 1995-05-26 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1998-05-25 1998-11-24 1999-05-26 $7700.00 Window Closed / Lapsed

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