US2569453A - Vitreous enamel base stock, vitreous enameled articles and method - Google Patents
Vitreous enamel base stock, vitreous enameled articles and method Download PDFInfo
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- US2569453A US2569453A US115706A US11570649A US2569453A US 2569453 A US2569453 A US 2569453A US 115706 A US115706 A US 115706A US 11570649 A US11570649 A US 11570649A US 2569453 A US2569453 A US 2569453A
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- ferrous metal
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- 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
- C23C22/05—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 aqueous solutions
- C23C22/06—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 aqueous solutions using aqueous acidic solutions with pH less than 6
- C23C22/07—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 aqueous solutions using aqueous acidic solutions with pH less than 6 containing phosphates
- C23C22/08—Orthophosphates
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- 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
- C23D—ENAMELLING OF, OR APPLYING A VITREOUS LAYER TO, METALS
- C23D3/00—Chemical treatment of the metal surfaces prior to coating
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
- Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
- Y10T428/00—Stock material or miscellaneous articles
- Y10T428/12—All metal or with adjacent metals
- Y10T428/12493—Composite; i.e., plural, adjacent, spatially distinct metal components [e.g., layers, joint, etc.]
- Y10T428/12535—Composite; i.e., plural, adjacent, spatially distinct metal components [e.g., layers, joint, etc.] with additional, spatially distinct nonmetal component
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
- Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
- Y10T428/00—Stock material or miscellaneous articles
- Y10T428/12—All metal or with adjacent metals
- Y10T428/12493—Composite; i.e., plural, adjacent, spatially distinct metal components [e.g., layers, joint, etc.]
- Y10T428/12535—Composite; i.e., plural, adjacent, spatially distinct metal components [e.g., layers, joint, etc.] with additional, spatially distinct nonmetal component
- Y10T428/12597—Noncrystalline silica or noncrystalline plural-oxide component [e.g., glass, etc.]
- Y10T428/12604—Film [e.g., glaze, etc.]
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
- Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
- Y10T428/00—Stock material or miscellaneous articles
- Y10T428/12—All metal or with adjacent metals
- Y10T428/12493—Composite; i.e., plural, adjacent, spatially distinct metal components [e.g., layers, joint, etc.]
- Y10T428/12681—Ga-, In-, Tl- or Group VA metal-base component
Description
- 12 Claims. 1 This invention relates to vitreous enameling, more particularly to a new and improved base stock forvitreous enamels, and to a new and improved method of controlling the adherence of vitreous enamels to ferrous metals.
It has long been recognized in the art of vitreous enameling that it would be desirable to apply a single coat of vitreous enamel to a ferrous metal sheet and thereby eliminate the necessity for a ground or grip coat of vitreous enamel. It has also been recognized in theart that it would be desirable to provide a ferrous metal base sheet to which low firing and high firing enamels would adhere and which would also have nonwarping properties and other desirable characteristics. Despite this recognition, the problem of providing a ferrous metal base sheet of the character described has not heretofore been solved in a satisfactory manner. Even the special low carbon enamel irons which have been proven to be the best from the standpoint of less warpin with high firing titanium oxide vitreous enamels must have a ground coat of a vitreous enamel prior to the finish coat of vitreous enamel in order to secure proper adherence and to avoid such defects as black specking.
One of the objects of the present invention is to provide a new and improved ferrous metal base sheetto which a finish coat of vitreous from various types of vitreous enamels in white and pastel colors with but one coat of enamel. Other objects will appear hereinafter.
In accomplishing these objects in accordance with this invention it has been found that a new and improved ferrous metal base sheet for vitreous enamels may be prepared by a process involving (1) Surface etching the ferrousmetal base stock, preferably with a fine grained etch,
. in a sulfuric acid bath which preferably also contains an oxidizing agent to accelerate the pickling action and an inhibitor to prevent the formation of iron compounds; (2) applying to the etched surface of said base stock, preferably after rinsing but before drying, a bath containing P205 in chemically combined form and a reducing sulfur compound capable of liberating free sulfur;
(3) applying to the resultant surface of said base stock, preferably after rinsing or drying, a coating of antimony; and (4) applying to the antimony coating, preferably after rinsing with water or drying, a coating of nickel.
In order to accomplish the purpose of the invention and to provide a ferrous metal base stock which can'be employed for a one-coat vitreous enamel of either a high firin or low firing type, it is important to use a ferrous metal, such as ingot iron or other ferrous metal, wherein the maximum carbon content does not exceed 0.05% carbon and which is essentially free from elements other than iron except for small quantities of manganese and possibly minute quantities ofsulfur and phosphorus. The low carbon content is desirable because the probability of warpage after firing with high firing enamels, i. e, enamels fired at temperatures above about 1500 degrees F., increases as the carbon content exceeds 0.05%. If the probability of warpage is not too serious the manganese content may be as high as 0.30%. The sulfur and phosphorus contents should be as low as possible. The chemistry of the ferrous metal base stock, therefore, may
the practice of the present invention with ferrous metal base sheets consisting essentially of. iron containing .02 to .03 carbon and .04 to .05 manganese, and with ferrous metal base sheets containing .02 to .04 carbon and .12 to .15 manganese. The gauge of the sheets may vary over a wide range as, for example, from 4 to 31 gauge, depending upon the use which is to be made of the finished vitreous enamelled article.
In the accompanying drawings I Figure 1 represents in perspective a sheet of ferrous metal base stock which has been subjected on one side only to the four-phase treatment outlined above;
. Figure 2 illustrates the ferrous metal base stock of Figure 1 with a coating of vitreous enamel thereon; and Figures 3 and 4 illustrate a ferrous metal base ,stock corresponding respectively to that shown A typical anal-.
tons sulfate is preferably. "added to the -first pickling bath in order to condition-the bath. The
ferrous sulfate however, tendsto build up in the bath as successive quantities of material are passed through or immersed (in the-'ibath. As,
the ferrous sulfate of the bath increases, however, the rate of activation of the ferrous base metalby the etching bath becomes slower and it :is preferred for the "purpose of this invention to'maintain a ferrous sulfate concentration not greater than about 2 pounds FeSOmHzO per gallon ofthe etching bath. The initial ferrous sulfate concentration is preferably about 17.5 grams per 'gallonpfbath.
"Sodium bisulf ate 'is preferably employed in the first-bath for its'buffering action and toassistin obtaining a cleaner sheet.
It 'has beenfound that the sulfuric acid pickle alone without any auxiliary ingredients will not v give *the desired result-due to the formation of spots or black specks after the vitreous-enamel coat has been applied to the base sheet. The presence of nickel andcobalt in the lfirst pickling bath tends to aggravate black specking and 'therefore should-be avoided. For the same reason it isdesirable that the first/pickling bath 'be essentially-free from chlorides such as would be produced, for'example, by adding hydrochloric acid to the'pickling bath; The black speckin'g seems 'to be "due inpart at least to the "formation of iron salts or other -impur-ities. The black "speck'ingdifliculty isoVercome'in the practice of the invention Joy-adding to the first pickling or surface etching 'bath'a salt of an alkali metal or an'alkaline'earth metal salt 'or a titanium salt.
The best results have-been obtained with stronitium salts, as, for example, strontium carbonate. "Other specific I illustrations of salts that have been employed effectivelyare lithium carbonate (152603) lithium phosphate "(LiaPOiiJ/ 'HZ'O.) and titanyl sulfate (TizfSOiiaiSHzO) The temperature andtime of treatment -in"the first bath will vary depending upon the gauge "and other physical characteristics of the fer-rous metal being etched but in general the temperature of the etching bath will vary Within the "range of 14'0 degrees Feto 185 degrees F. andthe time of treatment will vary within-a rangeof 12 to 25 minutes. For a -2O gauge enamel iron-sh'eet the optimum temperature-is around-1'55 degrees F. 'to 160 degrees .for 15 minutes infthes'first hath. For heavier sheets the temperature and time of treatment may be more and. .for lighter sheets the temperature and time of -treatment may be less.
*It' preferable-toeffe'ct the treatmentzin the first surface etching bath under asfoamwblanket which can he obtained in a well rknown imannerx by-adding a smallamount :of a foaming agent tothebath. I
Afterthe-surface etching in the first-bath it "is .preferable to rinse 'the ferrous -metal sheet or to prevent formation of iron salts. The rinsin may be effected at ordinary temperatures of say degrees F. to 75 .degrees F. with tap water which is preferably maintained slightly acid, that is, around a pH of 3 to 3.5 by the addition of-small amounts, usua11 yi5%"to ;1.% by weight,
of sulfuric acid. 'The acidaddition tends to prevent the formation of iron salts.
In what has been described as the second phase ofthe invention .the ferrous metal sheet or other article; which has been surface etched in the first phase is further treated in a bath which has an additionaletchin'g action on the sheet and provides a-coating 'o'f'what may be described as an 15 oxidation promoting agent.
Both sulfur and phosphorus appear to be effective for the purzpose ofsthe invention. The presence of sulfur in particular seems to be essential in order to secure the-desired adherence of the subsequently applied vitreous enamel. Attempts to. use other oxidizing :agentssuch as: sodium chlorate:zh'ave proved:to-beineifective.
Sulfur is supplied tothe'ferrous iba'se qnetalin the second phase of the -.imzenti'on1 by addingdzothe etching bathiemployedlforitheetreatmentinf th'e ferrous-metal iaisulfurficompoundiiwhic e- =composes to :liberate Ffree :sulfur. I he sulfurrais thereby-s formed J incia nascentizstate as i colloidal sulfur. .Amongsthe compounds .whichrhavezbeen found :;to ."be effectiveiaresodiumchydrosulflte and sodium xthiosulfate.v lather sulfur :compountls such asithe. polysulfides mayrberused. Therhydrosulfites :and :the thiosulfatcssboth have-:reflucing actions in an acidibathflbut'whetheraorrmit a reduction poccurs ndoes notappear to heumportant'f or the purpose of :theinyention.
'By employing. :phosphoric: acid :in attic second etching :bath :zanda-addingea; sulfur aliberating oom,-
pound thereto, ":it is epossible .ato .sproduce :asheet containing both phosphorus-randrsulfur. "Addition .ag'ents zwlhicht'inhibit -..the= formation of salts such as those .described iwithtrespect' :to the :first phaseofthe invention shouid iaisomreferably be employed :in .thersecondphase of the invention.
The :temperaturecof :th'e etreatment in the-second phasesofithe :invention mayvaryizwithin' the range-of 14.0 adegreesv Fmto :185 degreesFi, as in thedfirst phase.
' The time 10f treatment inn-the secondmhajseisof "theinventi'on may vary, depending upon the-adesired-gphosphaterooating :on: the sheet; andiismreferably within the range of 5 to 25 minutes.
- Theq-uantity'x'ofephosphorus .011 ithesheet after the :second phase of -the--:iny.ention'isasubject to variation :but .is preferably -.:within the: range-10f .0005 to 0.03 gram per square foot cuff-surface,
calculated as 13205.
:After-the-:secondxphase of :the zinyentiomathe ferrous metal base rsheeltf or other article im'ay. 'zbe dried directly or :may :be r rinsed with .cold: water and is thensiready.-.rfor 'themthird ephase of' izhe V "invention; I
.In the athird' rphaseiiof :the invention" the eetched surfaceof :the; ferrous :metal. is sealedwi tlaia coating-10f. antimony." 'Thissmayzbe accomplished either :byr-plating the antimony ith applied 'elem tromotiveaforce orbyxzpla'ting'zit' iby overeyoltage out of :a suitable bath. .An :antimony'tbathr-which is'essentially antimony potassium tartrateiis.pref- 'erable for the apurposepf :the :invention. A; reduc- '-ing 'a'gentgpreferably :a.ithiosulfata -mayybe" employe'd-as sanzzoptional :ingredient-:-in'-theantimony ba'tha ufhesantimonyscoatingiin"conjuncitiomwith the -su-bsequently'.appiiedcnickel acoating: improves other article-to avoid"carryover of the bath and' theadhereneerpfzthe vitreousienamelp-sheet. even superimposed on direct current.
when the second phase of the invention isomitted. The thickness of the antimony coating may vary but is preferably within the range from 5 to 50 millionths inch.
After the third phase of the invention the resultant product may be dried directly or rinsed with water and is then ready for the application of a thin plate of nickel. The nickel is preferably applied by an over-voltage from an alkaline bath of nickel salts but may be applied by electrodeposition using applied electromotive force either in the form of direct current or alternating current The amount of nickel applied to the surface of the ferrous metal base stock is subject to variation but is preferably within the range of 7 to 20 millionths inch thickness. After the nickel coat has been applied over the antimony coat the sheet may be dried and is then ready for vitreous enameling with either low firing or high firing types of vitreous enamels. Excellent results have been obtained in the application to this type of sheet of a single coat of a high firing titanium oxide enamel which is fired at 1480 degrees F. to 1540 degrees F.
The invention will be illustrated, but is not lim- .ited by the following examples in which the quantities are stated in parts by weight unless otherwise indicated.
Example I Sheets of iron in the form of racks consisting of 6 sheets each of a 20-gauge thickness and 3" x 6" dimensions are etched in a bath composed of the following ingredients:
280 cc. sulfuric acid (concentration suificient to give 6 H2804 by weight of bath) 35 grams ferrous sulfate (FBSO4.7H2O) 10 grams sodium bisulfate (NaHSO4.H2O)
2 grams lithium phosphate (Li3PO4. H2O) 1 gram manganese dioxide 0.5 gram isopropylnaphthalene sodium sulfonate (Santomerse No. 1)
200 cc. of 72% phosphoric acid fHaPOr) 2 grams lithium phosphate (LisPorJ/zHzO) 1.14 grams sodium hydrosulfite (Na2S2O4) made up to 2 gallons with water.
The sheets are immersed in this bath at a temperature of 155 degrees F. to 160 degrees F. for minutes. They are then removed from the bath and rinsed with cold water at a temperature of 60 degrees F. to 75 degrees F.
The treated sheets are then immersed in a bath composed of the following ingredients:
76 grams tartar emetic imsboicmioa /mzoi 152 grams sodium thiosulfate (NazSzOafiHaO) made up to 2 gallons with Water.
The pH of this bath is held around 5.5 to 5.7 and the sheets are immersed for a period of time from /2 minute to 15 minutes.
The antimony plated sheets are rinsed with "water at 60 degrees. F. to 75 degrees F; and are;
immersed in an alkaline nickel plating bathhaving the following composition: I
made up to 2 gallons with water and to a pH of 8 to 10 with dilute ammonium hydroxide.
The nickel is plated onto the antimony coating of the ferrous metal base sheet by over-voltage at a temperature of 190 degrees F. to 200 degrees F. for periods varying from 1 minute to 15 minutes. I
In preparing the foregoing bath the nickel chloride and ammonium chloride are mixed together and purified by the addition of 10 cc. of hydrogen peroxide at a temperature of degrees F. The hydrogen peroxide oxidizes any iron present and the iron precipitates when the pH is raised to 8 to 10 by the addition of the ammonium hydroxide. Dilute ammonium hydroxide is employed because concentrated ammonium hydroxide will precipitate nickel. The sodium hypophosphite in this bath acts as a reducing agent and-the quantity thereof may vary within the range of 0.5 gram to 15 grams per liter of bath.
The resultant ferrous metal base stock when coated with a vitreous enamel and fired yields an excellent vitreous enamel coated sheet. For example, a high firing titanium oxide enamel (Chicago vitreous enamel CV-1452) was applied to sheets prepared as above described and fired at 1520 degrees F. for 3 to 4 minutes. The resultant sheet showed excellent adherence and freedom from black specking.
An analysis of the sheetafter various time intervals in the foregoing bath showed the following P205 content on the surface:
The process is carried out as described in Example I except that the sodium thiosulfate is omitted in the antimony potassium tartrate bath (tartar emetic bath). Good results are obtained but not quite as good as those obtained with the s ium thiosulfate.
Example IV The invention is carried out as described in Ex.- ample I using sodium hydrosulfite instead of sodium thiosulfate in the antimony plating bath in the same proportions with substantially the same results. I v
. Ex'ample V v The invention is""carried out a'sdesc'ribed m Example I 'using a 'nickel'bath of the-followin composition-instead of the alkaline. nickel bath described in Example- I:
2272-grams nickel' 'sulfate (NiSOefiH-zO) 4 54.grams nickel chloride (NiClz) I14 grams citric acid made'up toz gallonsiiwith water.
This bath is purified --in a mannersimilar ?to the a1ka1ine" bath by mixing *the nickel sulfate and nickel chloride with water at a temperature 01 160 degrees F., bringing the pH to 6, adding hydrogen peroxide E'and ifiltering. The citric acid *is added to the filtrate and the ,pH is brought to-'z=2 .'5 by adding nickel carbonate. -Nick'elis plated out ofethe bathonto'the ferrous metal 'base'stock at a temperature of '140: degrates-F. to 160 degrees F. at 4oamperesper square foot current density. Various thicknessesof the nickel-are plated by setting the rheostatat :10 amperes'and-varying theplating time over a. perlodof 5 to 50 seconds.
Thecitric' acid in this bath functions primarily asea bufier. Tartaric acidmay be .used instead of citricaoidbut is not as effective. Likewise. other buffers, such as boric acid,are'not as effective as citric acid.
It will be .understood that variations maybe made in the-exact procedure andipropo'rtions describedabove provided they do "notdepart from ithe-invention. If the baths are to be usedaover and 'over a'gain the ingredients thereof must be ;-repleni'sh'ed 'from time to time. *For example; in the phosphoric acid bath described ins-Example I the sodium thiosulfate may be replenished by adding .57 gram of sodiumthiosulfate for each rack of six sheets 3".x 6. Those-skilled inthe art can readily determine .by .simpletestswhat additions are necessary to replenishargiven bath for treating ferrous metal .base stock.
'Referring' to the drawings and the. foregoing examples it will be seen that in Figure lthe ferrous metal base stock comprises a sheet I havinga surface etch'shownas alayer '2 which 1 corresponcls-to the-first phase treatmentya phosphorus and sulfur containing coating 3 corresponding to the second phase treatment, an antimony *coating 'l'corresponding to the'third phase treatment and a" nickel coating-5 corresponding to'the-fourth phase treatment.
a Figure 2 illustrates the ferrous metal base stock shown in Figure 1 after the application of a vitreousenamel coat 6.
In Figures 3 and 4 the coatings on the ferrous metal base stocks correspond to those in Fig- -'ures 1 and 2 and are given like numerals except that the coatings are on both sides of'the sheet.
It is believed that the invention provides for the first time a"'newa-andimproved type of ferrous metal base stock which is satisfactory "for the appli'catio'n of a-singl'e' finish coat of "either whig'h firing 'or' low firingv-itreous enamel without the necessity-for a ground coat. invention-also provides ferrous metal b'ase'stocks -char:a'.cterizedby improved adherence to vitreous enamels. Additionally the invention provides ferrous metal base stocks which may be enamelled directly with White or pastel shades of -vitreous enamels without black streaking.- The "vitreous enamelled--basestocks --an"dthe vitreous e-na'melled articles provided in :accordance with the 'invention are-a-lso essentially freefrom warpage and other undesirable characteristics.
'The 1:
ing 4%.to 8% by weight sulfuricacid,.aquantity The invention amakes it: possible-for .the enamelertio'employ zany of the commercially available vitreous enamel fritswithout'a special-knowledge as to the exact nature of the fritand-without applying aeground coat to-the base coat.
The invention'ishereby claimed as-follows: .1. :In ta .method of preparing low carbon Eferrous metals Ifor vitreous enameling, theysteps which consist essentially in acid picklingsaid ferrous .metal' i in 2a sulfuric acid 1 bath, depositing :on the pickled surface 'a coating of a ph sphate and elementalsulfur,:sealing said deposited coating with a thin :coating of antimony :and sealing .said coating of .antimony with a :thin coating-of nickel.
2. A method of :controlling the adherence aof vitreous enamels sto lowcarbon ferrous-metals in a sulfuric acid bath :which comprises 3-68- sentially 'acid pickling said ferrous metal,a:depositing on the pickled surface a coating :of-xa phosphate and elemental sulfur,:sealing saidzde posited coating with a thin coating-of antimony, sealing said coating of antimony with athin coating of nickel and'firing a vitreousenamel over said nickel coating.
--3. -In a method of: preparing ferrous metalsifor vitreous ena melingpthe steps which comprise .es-
depositing on the pickled surface-a coating. of-a phosphate andelemental sulfur, sealing said-deposited coating with a'thin coating of antimony and sealing saidccoatingofantimony with'athin coatingof nickel.
4. A method of controlling:the adherence-of vitreous enamels to ferrous-metals which comprises essentially acid pickling in asulfuric acid bath said ferrous metal .havingan average ,carbon content notgreater than about 0.05 by weight, an average manganese content not great:
er than 0.30% by weight, an average phosphorus content not greater than about 0.010% by weight, an average sulfur content not greater than about 0.025% by-wei'ght and the remainder beinges sentially iron, depositing on..the pickled surface a coating of .a phosphate and elemental sulfur,
sealing said deposited coating with athincoating of antimony, sealing said coating of antimony with a thin coating of nickel and firing a vitreous enamel over said nickelcoating.
5. In a -:methodof preparing a low carbon ferrous metal for vitreous enameling, the s: steps which comprise essentially pickling a ferrous metal in a sulfuricacid picklingibathcontainof an oxidizing'compound of manganeseeffectiveto accelerate the rate of picklingand .a
elemental sulfurinsaid bath: to form;a' ferrous metal having an etchedasurfaceiwith: a coatipg ing sa'id coating with..a .thin: plated .icoatingnof 9 antimony and sealing said antimony coating with a thin plated coating of nickel.
6. A method of controlling the adherence of vitreous enamels to low carbon ferrous metals which consists essentially in pickling a ferrous metal in a sulfuric acid pickling bath containing 4% to 8% by weight sulfuric acid, a quantity of an oxidizing compound of manganese effective to accelerate the rate of pickling and a quantity of an inhibitor for the formation of black specks in the enamelled products rinsing the resultant pickled ferrous metal in a slightly acid bath, treating the pickled surface of the ferrous metal with a phosphoric acid etching bath containing an inhibitor for the formation of black specks in the enamelled product and a compound which decomposes to liberate elemental sulfur in said bath to form a ferrous metal having an etched surface with a coating of phosphate and elemental sulfur thereon, sealing said coating with a thin plated coating of antimony, sealing said antimony coating with a thin plated coating of nickel and firing a vitreous enamel over said nickel coating.
7. In a method of preparing a ferrous metal for vitreous enameling, the steps which comp-rise essentially acid pickling a ferrous metal having an average carbon content not greater than about 0.05% by weight, an average manganese content not greater than 0.30% by weight, an average phosphorus content not greater than about 0.010% by weight, an average sulfur content not greater than about 0.025% by weight and the remainder being essentially iron in a sulfuric acid bath containing 4% to 8% by weight sulfuric acid, a quantity of ferrous sulfate between 17.5 grams and two pounds per gallon of bath, a quantity of manganese dioxide, and a quantity of lithium phosphate, rinsing said pickled ferrous metal with a solution of 0.05%, to 1% sulfuric acid, treating the pickled surface with a bath of dilute phosphoric acid containing lithium phosphate and a quantity of an inorganic reducing sulfur compound decomposable in the bath to deposit elemental sulfur, sealing the resultant coated surface of the ferrous metal with a thin coating of antimony in the presence of a reducing inorganic sulfur compound which decomposes to liberate elemental sulfur and sealing the antimony coating with a thin coating of nickel.
8. A method of controlling the adherence of vitreous enamels to ferrous metals which consists essentially in acid pickling a ferrous metal having an average carbon content not greater than about 0.05% by weight, an average manganese content not greater than 0.30% by weight, an average phosphorus content not greater than about 0.010% by weight, an average sulfur content not greater than about 0.025% by weight and the remainder being essentially iron in a sulfuric acid bath containing 4% to 8% by weight sulfuric acid, a quantity of ferrous sulfate between 17.5 grams and two pounds per gallon of bath, a quantity of manganese dioxide, and a quantity of lithium phosphate, rinsing said pickled ferrous metal with a solution of 0.05% to 1% sulfuric acid, treating the pickled surface with a bath of dilute phosphoric acid containing lithium phosphate and a quantity of an inorganic reducing sulfur compound decomposable in the bath to deposit elemental sulfur, sealing the resultant coated surface of the ferrous metal with a thin coating of antimony in the presence of a reducing inorganic sulfur compound which decomposes to liberate elemental sulfur, sealing the antimony coating with a thin coating of nickel and firing a vitreous enamel over said, nickel coating.
9. A vitreous enamel base stock consisting essentially of a sulfuric acid pickled low carbon ferrous metal having on the pickled surface thereof a coating of phosphate and elemental sulfur, a thin coating of antimony over the phosphate and sulfur coating and a thin coating of nickel over the antimony coating.
10. A vitreous enamel base stock consisting essentially of a sulfuric acid pickled ferrous metal sheet having an average carbon content not greater than 0.05% by weight, an average manganese content not greater than 0.30% by weight, an average phosphorus content not greater than 0.010% by weight, an average sulfur content not greater than 0.025% by weight and the remainder being essentially iron, a coating of phosphate and elemental sulfur on the pickled surface of said sheet, a thin coating of antimony over said phosphate and said sulfur coating and a thin coating of nickel over said antimony coating.
11. A vitreous enamelled articleobtained by firing a vitreous enamel on a low carbon ferrous metal which has been acid pickled in a sulfuric acid bath and has had a coating of phosphate and sulfur deposited on the acid pickled surface and sealed with successive coatings of antimony and nickel.
12, A vitreous enamelled article obtained by firing a vitreous enamel on a ferrous metal having an average carbon content not greater than 0.05% by weight, an average manganese content not greater than 0.30% by weight, an average phosphorus content not greater than 0.010% by weight, an average sulfur content not greater than 0.025% by weight and the remainder being essentially iron, which has been acid pickled in a sulfuric acid bath and has had a coating of phosphate and sulfur deposited on the acid pickled surface and sealed with successive coatings of antimony and nickel.
ALLAN E. CHESTER. IRWIN HERBERT SCHRAM, JR.
REFERENCES CITED The following references are of record in the file of this patent:
UNITED STATES PATENTS Number Name Date 1,207,218 Roux Dec. 5, 1916 2,121,520 Curtin June 21, 1938 2,271,706 Morris Feb. 3, 1942 FOREIGN PATENTS Number Country Date 507,355 Great Britain June 14, 1939 OTHER REFERENCES Lange: Handbook of Chemistry, 6th ed.,
pages 196, 197 and 1169, publ. 1946 by Handbook Publishers, Inc., Sandusky, Ohio.
Claims (1)
- 6. A METHOD OF CONTROLLING THE ADHERENCE OF VITREOUS ENAMELS TO LOW CARBON FERROUS METALS WHICH CONSISTS ESSENTIALLY IN PICKLING A FERROUS METAL IN A SULFURIC ACID PICKLING BATH CONTAINING 4% TO 8% BY WEIGHT SULFURIC ACID, A QUANTITY OF AN OXIDIZING COMPOUND OF MANGANESE EFFECTIVE TO ACCELERATE THE RATE OF PICKLING AND A QUANTITY OF AN INHIBITOR FOR THE FORMATION OF BLACK SPECKS IN THE ENAMELLED PRODUCTS RINSING THE RESULTANT PICKLED FERROUS METAL IN A SLIGHTLY ACID BATH, TREATING THE PICKLED SURFACE OF THE FERROUS METAL WITH A PHOSPHORIC AICD ETCHING BATH CONTAINING AN INHIBITOR FOR THE FORMATION OF BLACK SPECKS IN THE ENAMELLED PRODUCT AND A COMPOUND WHICH DECOMPOSES TO LIBERATE ELEMENTAL SULFUR IN SAID BATH TO FORM A FERROUS METAL HAVING AN ETCHED SURFACE WITH A COATING OF PHOSPHATE AND ELEMENTAL SULFUR THEREON, SEALING SAID COATING WITH A THIN PLATED COATING OF ANTIMONY, SEALING SAID ANTIMONY COATING WITH A THIN PLATED COATING OF NICKEL AND FIRING A VITREOUS ENAMEL OVER SAID NICKEL COATING.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US115706A US2569453A (en) | 1949-09-14 | 1949-09-14 | Vitreous enamel base stock, vitreous enameled articles and method |
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US115706A US2569453A (en) | 1949-09-14 | 1949-09-14 | Vitreous enamel base stock, vitreous enameled articles and method |
| GB1994351A GB718514A (en) | 1951-08-23 | 1951-08-23 | Improvements in or relating to vitreous enameling |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| US2569453A true US2569453A (en) | 1951-10-02 |
Family
ID=26254331
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| US115706A Expired - Lifetime US2569453A (en) | 1949-09-14 | 1949-09-14 | Vitreous enamel base stock, vitreous enameled articles and method |
Country Status (1)
| Country | Link |
|---|---|
| US (1) | US2569453A (en) |
Cited By (12)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US2706692A (en) * | 1951-12-07 | 1955-04-19 | Poor & Co | Method of bonding vitreous enamels and articles produced thereby |
| US2832676A (en) * | 1956-01-05 | 1958-04-29 | North American Aviation Inc | Method of making thin-walled reentrant structure |
| US2918414A (en) * | 1956-08-17 | 1959-12-22 | Bradley Mining Company | Antimony plating process |
| US2980553A (en) * | 1958-06-23 | 1961-04-18 | Smith Corp A O | Glass coated steel article and method of making the same |
| US3156578A (en) * | 1961-05-24 | 1964-11-10 | Gen Electric | Steel pickling process for application of one-coat enamel |
| US3173875A (en) * | 1961-11-09 | 1965-03-16 | Wyandotte Chemicals Corp | Acid bowl cleaner |
| US3907650A (en) * | 1973-02-12 | 1975-09-23 | Xerox Corp | Photosensitive binder layer for xerography |
| US4125442A (en) * | 1976-09-10 | 1978-11-14 | Rogers Olbert W | Artificial teeth construction |
| US4427501A (en) | 1976-09-10 | 1984-01-24 | Rogers Olbert W | Method of manufacture of artificial teeth |
| US4488940A (en) * | 1982-05-14 | 1984-12-18 | Horst Wismann | Process for the production of dental replacement parts made of metal |
| EP0765952A1 (en) * | 1995-09-28 | 1997-04-02 | Sollac S.A. | Process for preparing the metallic surface of an object, especially a steel sheet, for a direct enamelling |
| US6199263B1 (en) | 1997-03-21 | 2001-03-13 | Sollac | Process for preparation of an article made of enameled sheet steel by a direct method |
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|---|---|---|---|---|
| US1207218A (en) * | 1914-01-19 | 1916-12-05 | L Aluminium Francais Soc | Process of producing metallic deposits. |
| US2121520A (en) * | 1936-09-24 | 1938-06-21 | Curtin Howe Corp | Maintenance of phosphate coating baths |
| GB507355A (en) * | 1938-02-28 | 1939-06-14 | Rene Jacques Kahn | Process for the improvement of phosphoric acid baths employed in metallurgy |
| US2271706A (en) * | 1940-06-18 | 1942-02-03 | Poor & Co | Process for coating metal surfaces |
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US1207218A (en) * | 1914-01-19 | 1916-12-05 | L Aluminium Francais Soc | Process of producing metallic deposits. |
| US2121520A (en) * | 1936-09-24 | 1938-06-21 | Curtin Howe Corp | Maintenance of phosphate coating baths |
| GB507355A (en) * | 1938-02-28 | 1939-06-14 | Rene Jacques Kahn | Process for the improvement of phosphoric acid baths employed in metallurgy |
| US2271706A (en) * | 1940-06-18 | 1942-02-03 | Poor & Co | Process for coating metal surfaces |
Cited By (14)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US2706692A (en) * | 1951-12-07 | 1955-04-19 | Poor & Co | Method of bonding vitreous enamels and articles produced thereby |
| US2832676A (en) * | 1956-01-05 | 1958-04-29 | North American Aviation Inc | Method of making thin-walled reentrant structure |
| US2918414A (en) * | 1956-08-17 | 1959-12-22 | Bradley Mining Company | Antimony plating process |
| US2980553A (en) * | 1958-06-23 | 1961-04-18 | Smith Corp A O | Glass coated steel article and method of making the same |
| US3156578A (en) * | 1961-05-24 | 1964-11-10 | Gen Electric | Steel pickling process for application of one-coat enamel |
| US3173875A (en) * | 1961-11-09 | 1965-03-16 | Wyandotte Chemicals Corp | Acid bowl cleaner |
| US3907650A (en) * | 1973-02-12 | 1975-09-23 | Xerox Corp | Photosensitive binder layer for xerography |
| US4125442A (en) * | 1976-09-10 | 1978-11-14 | Rogers Olbert W | Artificial teeth construction |
| US4427501A (en) | 1976-09-10 | 1984-01-24 | Rogers Olbert W | Method of manufacture of artificial teeth |
| US4488940A (en) * | 1982-05-14 | 1984-12-18 | Horst Wismann | Process for the production of dental replacement parts made of metal |
| EP0765952A1 (en) * | 1995-09-28 | 1997-04-02 | Sollac S.A. | Process for preparing the metallic surface of an object, especially a steel sheet, for a direct enamelling |
| FR2739396A1 (en) * | 1995-09-28 | 1997-04-04 | Lorraine Laminage | PROCESS FOR PREPARING THE METAL SURFACE OF AN OBJECT, IN PARTICULAR IN A STEEL SHEET, FOR DIRECT MODE ENAMELLED |
| US5766374A (en) * | 1995-09-28 | 1998-06-16 | Sollac | Process for preparing the metal surface of an article, especially one made of steel sheet, for direct-on enameling |
| US6199263B1 (en) | 1997-03-21 | 2001-03-13 | Sollac | Process for preparation of an article made of enameled sheet steel by a direct method |
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