GB641091A - Improvements in and relating to methods of blackening stainless steel - Google Patents

Improvements in and relating to methods of blackening stainless steel

Info

Publication number
GB641091A
GB641091A GB12917/47A GB1291747A GB641091A GB 641091 A GB641091 A GB 641091A GB 12917/47 A GB12917/47 A GB 12917/47A GB 1291747 A GB1291747 A GB 1291747A GB 641091 A GB641091 A GB 641091A
Authority
GB
United Kingdom
Prior art keywords
stainless steel
per cent
steel
articles
chromium
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
GB12917/47A
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.)
ALLOY RES CORP
Original Assignee
ALLOY RES CORP
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
Application filed by ALLOY RES CORP filed Critical ALLOY RES CORP
Publication of GB641091A publication Critical patent/GB641091A/en
Expired legal-status Critical Current

Links

Classifications

    • 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
    • C23C22/00—Chemical surface treatment of metallic material by reaction of the surface with a reactive liquid, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals
    • C23C22/70—Chemical surface treatment of metallic material by reaction of the surface with a reactive liquid, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals using melts
    • C23C22/72—Treatment of iron or alloys based thereon

Abstract

A method of blackening stainless steel (defined as a low-carbon steel comprising 10-35 per cent chromium, with or without nickel and with or without additions of manganese, silicon, cobalt, copper, molybdenum, tungsten, vanadium, columbium, titanium, and the balance iron) or articles thereof, comprises immersion of the steel or article in a molten bath consisting of sodium and/or potassium dichromate, at a temperature preferably between 320 DEG C and 500 DEG C. The articles are preferably first cleaned or pickled-a suitable pickle being an aqueous solution of 20 per cent nitric and 1 per cent hydrofluoric-acid-and may be polished either mechanically or electrolytically to obtain a lustrous black finish. The black coating produced is said to be rich in oxides of iron and chromium. In specific examples, molten sodium dichromate alone is used at between 320 DEG C and 400 DEG C for treating 18-8 stainless steel; a mixture of 80 parts by weight of sodium dichromate and 20 parts potassium bichromate is used at 430 DEG -500 DEG C for any stainless steel.
GB12917/47A 1942-12-31 1947-05-13 Improvements in and relating to methods of blackening stainless steel Expired GB641091A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US470853A US2394899A (en) 1942-12-31 1942-12-31 Stainless steel and method of coating same

Publications (1)

Publication Number Publication Date
GB641091A true GB641091A (en) 1950-08-02

Family

ID=23869331

Family Applications (1)

Application Number Title Priority Date Filing Date
GB12917/47A Expired GB641091A (en) 1942-12-31 1947-05-13 Improvements in and relating to methods of blackening stainless steel

Country Status (3)

Country Link
US (1) US2394899A (en)
FR (1) FR925517A (en)
GB (1) GB641091A (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB2120682A (en) * 1982-04-23 1983-12-07 Stephanois Rech Mec Improving the corrosion resistance of ferrous metal parts by molten salt bath treatment to remove sulphur; filtering molten salts

Families Citing this family (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2513302A (en) * 1945-02-17 1950-07-04 Armco Steel Corp Black oxide coated nitrided stainless steel product
US2537035A (en) * 1945-05-29 1951-01-09 Armco Steel Corp Method of coating stainless steel
US2542994A (en) * 1945-07-09 1951-02-27 Armco Steel Corp Electrolytic surface treatment of steel
US2499764A (en) * 1945-11-24 1950-03-07 Armco Steel Corp Processing stainless steel
US2513303A (en) * 1946-12-30 1950-07-04 Armco Steel Corp Coated cobalt alloy products
US2613280A (en) * 1950-08-16 1952-10-07 Joseph A Petnel Telephone dial
US3437532A (en) * 1965-07-14 1969-04-08 Allegheny Ludlum Steel Dark colored stainless steel surfaces
US3540942A (en) * 1968-02-05 1970-11-17 Nasa Process for applying black coating to metals
JPS6014275B2 (en) * 1975-09-22 1985-04-12 矢崎総業株式会社 Selective absorption surface of solar heat collector and its manufacturing method

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB2120682A (en) * 1982-04-23 1983-12-07 Stephanois Rech Mec Improving the corrosion resistance of ferrous metal parts by molten salt bath treatment to remove sulphur; filtering molten salts

Also Published As

Publication number Publication date
FR925517A (en) 1947-09-05
US2394899A (en) 1946-02-12

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