EP0048270B1 - Revetements de zinc-aluminium - Google Patents

Revetements de zinc-aluminium Download PDF

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Publication number
EP0048270B1
EP0048270B1 EP19810901054 EP81901054A EP0048270B1 EP 0048270 B1 EP0048270 B1 EP 0048270B1 EP 19810901054 EP19810901054 EP 19810901054 EP 81901054 A EP81901054 A EP 81901054A EP 0048270 B1 EP0048270 B1 EP 0048270B1
Authority
EP
European Patent Office
Prior art keywords
weight
mischmetal
coating
zinc
bath
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired
Application number
EP19810901054
Other languages
German (de)
English (en)
Other versions
EP0048270A4 (fr
EP0048270A1 (fr
Inventor
Schrade F. Radtke
Dimitri Coutsouradis
Jacques Pelerin
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
International Lead Zinc Research Organization Inc
Original Assignee
International Lead Zinc Research Organization Inc
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Priority claimed from BE6/471152A external-priority patent/BE882431A/fr
Application filed by International Lead Zinc Research Organization Inc filed Critical International Lead Zinc Research Organization Inc
Priority to AT81901054T priority Critical patent/ATE14900T1/de
Publication of EP0048270A1 publication Critical patent/EP0048270A1/fr
Publication of EP0048270A4 publication Critical patent/EP0048270A4/fr
Application granted granted Critical
Publication of EP0048270B1 publication Critical patent/EP0048270B1/fr
Expired legal-status Critical Current

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Classifications

    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C18/00—Alloys based on zinc
    • C22C18/04—Alloys based on zinc with aluminium as the next major constituent
    • C—CHEMISTRY; METALLURGY
    • C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
    • C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
    • C23C2/00—Hot-dipping or immersion processes for applying the coating material in the molten state without affecting the shape; Apparatus therefor
    • C23C2/04—Hot-dipping or immersion processes for applying the coating material in the molten state without affecting the shape; Apparatus therefor characterised by the coating material
    • C23C2/06—Zinc or cadmium or alloys based thereon

Definitions

  • the present invention is directed to the application of zinc coatings to a substrate - commonly sheet steel.
  • the invention concerns a protective metal coating, which may be deposited from hot-dip metal bath on a substrate, said coating comprising at least about 85% by weight Zn, from about 3% to about 15% by weight AI and from about 5 ppm to about 1.0% by weight of mischmetal, the percentage of mischmetal being calculated on the total of Zn and Al.
  • the protective metal coating may be obtained by deposition from hot-dip metal baths, and hence the coatings obtained therefrom, may vary considerably just as known zinc-aluminum coatings may vary. In each instance however, it is essential that the coating contains a mischmetal alloy in an amount sufficient to yield the improved results observed and described herein.
  • mischmetal refers to a variety of known rare earth alloys.
  • a typical cerium mischmetal might have the following composition (in weight %):
  • mischmetal referes to the above composition as well as other mischmetal compositions readily apparent to those skilled in the art.
  • the alloy to which mischmetal is to be added is a zinc-aluminum alloy containing from about 3% to about 15% by weight aluminum. Such alloys typically contain about 5% aluminum. These alloys may contain constituents in addition to mischmetal such as Fe, Fb, Sb, Mg, Sn, Cu and Si.
  • one embodiment of the invention uses a low aluminum (i.e., 3-15% by weight) zinc bath containing Pb or Sn as well as mischmetal.
  • Pb and Sn are known additives to galvanizing baths for modifying the fluidity of the liquid metal or the spangle of the solidified coating.
  • Zinc-aluminum alloys containing lead and also Mg and Cu are reported to be immune to grain boundary corrosion.
  • mischmetal additions have been shown to exhibit a pronounced beneficial effect as regards soundness and uniformity.
  • a Zn-AI alloy containing Mg, Pb, Cu and mischmetal is encompassed by the present invention.
  • a typical composition might contain 3-15% by weight AI, 0.02-0.15% by weight Mg, 0.02-0.15% by weight Pb and possibly 0.1-0.3% by weight Cu, the balance being Zn with mischmetal additions.
  • mischmetals may be advantageously used according to the invention, including mixtures of mischmetals in a single zinc bath or coating.
  • a La-mischmetal and a Ce-mischmetal may be added simultaneously, preferably in an amount such that the total mischmetal concentration is within the ranges described above, i.e. from about 5 ppm to about 1.0% and preferably from about 0.01 to 0.1% by weight.
  • a master alloy may be first prepared and then added to the zinc bath so as to yield the desired mischmetal concentration.
  • Such master alloys might be comprised of 20% by weight Zn and 80% by weight mischmetal or 85-95% by weight AI and 15-5% by weight mischmetal.
  • Specimens of rimming steel sheet measuring 68 x 120 x 0.7 mm were galvanized in a device simulating a continuous galvanizing bath. They were first preheated in an atmosphere containing 95% N Z 5% H 2 at different temperatures from 750 to 800°C for times ranging from 1 to 10 minutes. After this heating stage the specimens. were transferred from the hot zone of the furnace, cooled down to about 430°C and then introduced into a zinc alloy bath maintained at 430°C and protected by the 95% N Z -5% H 2 atmosphere. They were maintained in the zinc bath for periods ranging from 5 to 60 seconds and then removed from the bath and cooled in a jet of 95% N Z -5% H 2 atmosphere. They were maintained in the zinc bath for periods ranging from 5 to 60 seconds and then removed from the bath and cooled in a jet of 95% N2-5% H 2 gas.
  • the specimens contained a high proportion of uncoated areas and bare spots. This was the case even as to the specimens pretreated at the highest temperature and longest annealing time in the reducing atmosphere.
  • the addition of 0.15% by weight Sb in a Zn-5% by weight AI bath resulted in a decrease in the amount of bare spots but still. up to 33% of the galvanized faces presented bare spots.
  • a third bath containing 5% by weight AI and 0.02% by weight Ce added as Ce-mischmetal resulted in 100% good coatings for a range of heat treating conditions.
  • a bath containing Zn-5% by weight Al, 0.03% by weight La and 0.025% by weight Ce added as La and Ce mischmetal gave rise to 100% good coatings even for preheating temperatures as low as 750°C.
  • This example relates to trials carried out with a pilot continuous annealing and galvanizing plant.
  • 800 kg coils of rimming steel sheet 150 mm wide and 0.25 mm thick were first treated in a Selas type furnace at temperatures ranging from 680 to 860°C.
  • the sheet was then cooled in a controlled atmosphere to about 430°C and then introduced into a seven-ton zinc bath.
  • the sheet was then nitrogen-gas wiped at the exit, jet cooled and finally coiled.
  • the speed of the sheet varied in the range 10 to 30 m/min.
  • a Zn-5% by weight AI bath containing 0.13% by weight Sn and as above 0.05% of cerium mischmetal was also used in the pilot galvanizing line.
  • the coatings obtained had characteristics similar to those described above with a coating somewhat less bright due to a different spangle behavior.
  • An additional bath containing Zn, 5% by weight Al, 0.13% by weight Sn, 0.05% by weight Pb and about 0.05% by weight Ce + La (added as Ce mischmetal or La mischmetal; or added as a master alloy containing about 20% by weight Zn and 80% by weight La and/or Ce mischmetals; or added as a master alloy containing about 90% by weight AI and 10% by weight La and/or Ce mischmetal) was also used in the pilot galvanizing line.
  • the coatings obtained showed a wide range of thickness, were uniform and again were free of bare spots and uncoated areas.
  • the formability and adherence was evaluated by means of bulge tests and Erichsen tests. In both types of tests the coatings obtained with the mischmetal-containing bath exhibited and adherence and formability equivalent to that of standard galvanized coatings. For example a 180° bending gave rise to no cracking and in the Erichsen test a depth of 9 mm was made on 0.25 mm thick sheets without peeling of the coating.
  • the corrosion resistance, in a salt spray test, of the Zn-AI coatings containing mischmetal was more than twice that of a standard galvanized coating of the same thickness.
  • the time to first rusting was about 900 hours instead of 350 hours with a conventional galvanized coating of the same thickness.
  • the corrosion resistance in an environment containing 10 ppm S0 2 was shown to be at least 50% greater than that of a conventional galvanized coating.
  • the galvanic protection of the Zn-AI mischmetal coating was also determined by examining the progress of corrosion around scratches machined on specimens exposed to a SO z -containing environment.
  • the galvanic protection of the mischmetal-containing Zn-5% AI coating was equal to that of a pure zinc coating and far superior to that of a coating containing Zn-55AI-1.5Si.

Landscapes

  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Materials Engineering (AREA)
  • Mechanical Engineering (AREA)
  • Metallurgy (AREA)
  • Organic Chemistry (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Coating With Molten Metal (AREA)

Abstract

Alliages destines a etre utilises dans un bain de galvanisation de zinc comprenant du zinc, de l'aluminium et un alliage contenant une terre rare telle que du mischmetal. Selon les modes preferentiels de realisation, l'alliage contient de 80% a 97% environ de zinc, de 3% a 15% environ d'aluminium et de 5 ppm a 1,0% environ de mischmetal. L'alliage peut aussi contenir un ou plusieurs des elements Fe, Pb, Fb, Mg, Sn, Cu et Si.

Claims (17)

1. Un revêtement métallique protecteur adhérent sur un substrat, ledit revêtement consistant en au moins environ 85 % en poids de Zn, d'environ 3 à environ 15 % en poids de AI et d'environ 5 ppm à environ 1,0 % en poids de mischmétal, le pourcentage de mischmétal étant calculé sur le total de Zn et AI.
2. Un revêtement selon la revendication 1 contenant d'environ 0,01 à environ 0,1 % en poids de mischmétal, ledit pourcentage étant calculé sur le total de Zn et AI.
3. Un revêtement selon la revendication 1, dans lequel le mischmétal est un mischmétal au Ce ou un mischmétal au La.
4. Un revêtement selon la revendication 2, dans lequel le mischmétal est un mischmétal au Ce ou un mischmétal au La.
5. Un revêtement selon la revendication 1, ledit revêtement contenant en outre au moins un des éléments choisis parmi Fe, Pb, Sb, Mg, Sn, Cu et Si.
6. Un revêtement selon la revendication 1, ledit revêtement contenant en outre de l'antimoine.
7. Un revêtement selon la revendication 6, ledit revêtement contenant en outre du plomb.
8. Un revêtement selon la revendication 7, contenant d'environ 0,03 à 0,15 % en poids de Sb et moins de 0,02 % en poids de Pb.
9. Un revêtement selon la revendication 1, ledit revêtement contenant en outre Mg et Pb.
10. Un revêtement selon la revendication 9 contenant d'environ 0,02 à 0,15 % en poids de Mg et d'environ 0,02 à 0,15 % en poids de Pb.
11. Un revêtement selon la revendication 10, ledit revêtement contenant en outre Cu.
12. Un revêtement selon la revendication 11 contenant d'environ 0,1 à 0,3 % en poids de Cu.
13. Un revêtement selon la revendication 3, dans lequel ledit mischmétal est un mischmétal au Ce consistant en environ 45-60 % en poids de Ce, d'environ 35 à 50 % en poids d'autres métaux des terres rares et le reste consistant en Fe, Mg, AI, Si et des impuretés.
14. Un procédé d'application d'un revêtement métallique protecteur sur un substrat comprenant l'étape d'immersion du substrat dans un alliage fondu consistant en zinc, aluminium et mischmétal, ledit bain ayant une composition telle qu'il donne un revêtement consistant en au moins environ 85 % en poids de Zn, d'environ 3 à environ 15 % en poids de AI et d'environ 5 ppm à environ 1,0 % en poids de mischmetal, le pourcentage de mischmétal étant calculé sur le total de Zn et AI.
15. Un procédé selon la revendication 14, dans lequel ledit mischmétal est ajouté à l'alliage sous la forme d'un alliage maître.
16. Un procédé selon la revendication 14, dans lequel ledit alliage maître consiste en 20 % de Zn et 80 % en poids de mischmétal.
17. Un procédé selon la revendication 14, dans lequel ledit alliage maître consiste en environ 85-95 % en poids de AI et environ 5-15 % en poids de mischmétal.
EP19810901054 1980-03-25 1981-03-18 Revetements de zinc-aluminium Expired EP0048270B1 (fr)

Priority Applications (1)

Application Number Priority Date Filing Date Title
AT81901054T ATE14900T1 (de) 1980-03-25 1981-03-18 Zink-aluminium-beschichtungen.

Applications Claiming Priority (4)

Application Number Priority Date Filing Date Title
BE47115 1980-03-25
BE6/471152A BE882431A (fr) 1980-03-25 1980-03-25 Procede de formation de revetement zinc-aluminium
BE47373 1981-01-16
BE6047373 1981-01-16

Publications (3)

Publication Number Publication Date
EP0048270A1 EP0048270A1 (fr) 1982-03-31
EP0048270A4 EP0048270A4 (fr) 1982-07-12
EP0048270B1 true EP0048270B1 (fr) 1985-08-14

Family

ID=25662147

Family Applications (1)

Application Number Title Priority Date Filing Date
EP19810901054 Expired EP0048270B1 (fr) 1980-03-25 1981-03-18 Revetements de zinc-aluminium

Country Status (6)

Country Link
EP (1) EP0048270B1 (fr)
JP (1) JPH0124221B2 (fr)
BR (1) BR8107944A (fr)
CA (1) CA1175686A (fr)
IN (1) IN156009B (fr)
WO (1) WO1981002748A1 (fr)

Families Citing this family (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
BE890256A (fr) * 1981-09-07 1982-03-08 Centre Rech Metallurgique Perfectionnements aux procedes de galvanisation des toles ou bandes en acier
EP0148740A1 (fr) * 1983-12-22 1985-07-17 CENTRE DE RECHERCHES METALLURGIQUES CENTRUM VOOR RESEARCH IN DE METALLURGIE Association sans but lucratif Procédé de revêtement à chaud et bain de composition améliorée pour sa mise en oeuvre
EP0958395A1 (fr) * 1996-05-02 1999-11-24 N.V. Bekaert S.A. Fil pour ressort, au chrome et au silicium
JP3343498B2 (ja) * 1997-06-13 2002-11-11 昭和電工株式会社 低温ろう付用ろう材
JP4136286B2 (ja) * 1999-08-09 2008-08-20 新日本製鐵株式会社 耐食性に優れたＺｎ−Ａｌ−Ｍｇ−Ｓｉ合金めっき鋼材およびその製造方法
WO2001064971A1 (fr) * 2000-02-29 2001-09-07 Nippon Steel Corporation Article en acier plaque dote d'une grande resistance a la corrosion ainsi que d'une remarquable aptitude au formage et procede de production
CN115874075B (zh) * 2022-12-16 2023-10-13 佛山市桂源锌合金材料有限公司 一种低杂质且易抛光的锌合金及其制备工艺

Family Cites Families (15)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE926654C (de) * 1951-10-31 1955-04-21 Goldschmidt Ag Th Sicherheitszuendsteine fuer Grubenlampen in schlagwettergefaehrdeten Bergwerksbetrieben
US2829973A (en) * 1953-04-09 1958-04-08 Magnesium Elektron Ltd Magnesium base alloys
FR1155357A (fr) * 1956-08-02 1958-04-25 Treibacher Chemische Werke Ag Procédé de filage d'alliages pyrophoriques de ferrocérium
DE1231906B (de) * 1964-03-06 1967-01-05 Zink Ind Vorm Wilhelm Grillo A Verwendung von lanthan- und gegebenenfalls cerhaltigen Zinklegierungen als Aktivanoden fuer den kathodischen Korrosionsschutz
US3343930A (en) * 1964-07-14 1967-09-26 Bethlehem Steel Corp Ferrous metal article coated with an aluminum zinc alloy
GB1115673A (en) * 1964-07-14 1968-05-29 Bethlehem Steel Corp Zinc-aluminum coated products and methods therefor
CA850045A (en) * 1966-07-11 1970-08-25 Cominco Ltd. Process for the production of coloured coatings
LU53446A1 (fr) * 1967-04-18 1968-12-11
US3527601A (en) * 1967-06-14 1970-09-08 Dow Chemical Co Process of making creep-resistant zinc-base alloys
LU55104A1 (fr) * 1967-12-15 1969-07-17
BE746610A (fr) * 1970-02-26 1970-08-26 Centre Rech Metallurgique Alliages de zinc, a proprietes ameliorees,
US4152472A (en) * 1973-03-19 1979-05-01 Nippon Steel Corporation Galvanized ferrous article for later application of paint coating
US4056366A (en) * 1975-12-24 1977-11-01 Inland Steel Company Zinc-aluminum alloy coating and method of hot-dip coating
US4029478A (en) * 1976-01-05 1977-06-14 Inland Steel Company Zn-Al hot-dip coated ferrous sheet
US4213799A (en) * 1978-06-05 1980-07-22 Swiss Aluminium Ltd. Improving the electrical conductivity of aluminum alloys through the addition of mischmetal

Also Published As

Publication number Publication date
JPS57500475A (fr) 1982-03-18
EP0048270A4 (fr) 1982-07-12
EP0048270A1 (fr) 1982-03-31
CA1175686A (fr) 1984-10-09
IN156009B (fr) 1985-04-27
BR8107944A (pt) 1982-03-09
WO1981002748A1 (fr) 1981-10-01
JPH0124221B2 (fr) 1989-05-10

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