ASTM C286-99(2004)

NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
Contact ASTM International (www.astm.org) for the latest information.
Designation:C286–99(Reapproved 2004)
Standard Terminology Relating to
Porcelain Enamel and Ceramic-Metal Systems
This standard is issued under the fixed designation C286; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
This standard has been approved for use by agencies of the Department of Defense.
1. Scope C347 Test Method for Reflectivity and Coefficient of Scat-
ter of White Porcelain Enamels
1.1 These definitions pertain to the terminology used in the
C374 Test Methods for Fusion Flow of Porcelain Enamel
porcelain enamel and ceramic-coated metal industries.
Frits (Flow-Button Methods)
1.2 Words adequately defined in standard dictionaries are
C448 Test Methods for Abrasion Resistance of Porcelain
not included. Included are words that are peculiar to these
Enamels
industries.
C614 TestMethodforAlkaliResistanceofPorcelainEnam-
1.3 Hyphenated words, double words, or phrases are listed
els
alphabetically under the first word; additional important words
C633 Test Method for Adhesion or Cohesion Strength of
are cross-referenced.
Thermal Spray Coatings
1.4 When a word or phrase, listed as a synonym, is not
C743 Test Method for Continuity of Porcelain Enamel
separately defined, the defined word or phrase is the accepted
Coatings
or preferred form.
C756 Test Method for Cleanability of Surface Finishes
2. Referenced Documents
3. Terminology
2.1 ASTM Standards:
A424 Specification for Steel, Sheet, for Porcelain Enamel- abrasion resistance—the degree to which a porcelain enamel
ing will resist attack by abrasive materials.
A919 Terminology Relating to Heat Treatment of Metals
NOTE 1—See Test Methods C448.
C282 Test Method for Acid Resistance of Porcelain Enam-
els(Citric Acid Spot Test) acid annealing—an annealing process in which ferrous metal
shapes are coated with acid before and in conjunction with
C283 Test Methods for Resistance of Porcelain Enameled
the annealing.
Utensils to Boiling Acid
acid resistance—the degree to which a porcelain enamel will
C285 Test Methods for Sieve Analysis of Wet-Milled and
resist attack by acids.
Dry-Milled Porcelain Enamel
C313 Test Method for Adherence of Porcelain Enamel and
NOTE 2—See Test Method C283 and Test Method C282.
3 3
Ceramic Coatings to Sheet Metal
adherence—(1) the degree of adhesion of a porcelain enamel
C314 Discontinued 1981; Test Method for Flatness of
or other ceramic coating to a metal substrate.
Porcelain Enameled Panels
C346 Test Method for 45-deg Specular Gloss of Ceramic
NOTE 3—See Test Method C313.
Materials
(2) Stress necessary to cause separation of one material from
another at their interface.
NOTE 4—See Test Method C633.
This terminology is under the jurisdiction of ASTM Committee B08 on
aging—thestoringofporcelainenamelslipsorpowdersbefore
Metallic and Inorganic Coatings and is the direct responsibility of Subcommittee
use. The change occurring in slips or powders with the lapse
B08.12 on Materials for Porcelain Enamel and Ceramic-Metal Systems.
Current edition approved Oct. 1, 2004. Published October 2004. Originally
of time.
approved in 1951. Last previous edition approved in 1999 as C286 – 99. DOI:
air atomizing—air used to atomize powder and to control
10.1520/C0286-99R04.
2 powder/air mix and powder cloud density.
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
air fluidizer—air used to impart fluid-like properties to pow-
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
Standards volume information, refer to the standard’s Document Summary page on
der via a fluid bed.
the ASTM website.
alkali resistance—for porcelain enamels, the degree to which
Withdrawn.
4 a porcelain enamel will resist attack by aqueous alkaline
Withdrawn. The last approved version of this historical standard is referenced
on www.astm.org. solutions.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
C286–99 (2004)
NOTE 5—See Test Method C614.
boiling—a defect visible in the fired porcelain enamel caused
by gas evolution which results in the formation of blisters,
alligator hide—a defect characterized by an extreme rough-
pinholes, black specks, dimples, or spongy surface.
ness of the porcelain enamel surface: a severe case of orange
bolt-hole brush—a special round brush used to remove
peel.
porcelain enamel bisque from in and around small openings
aluminum enamel—a porcelain enamel specifically designed
in the ware.
for application to aluminum.
bond—see adherence.
annealing—see TerminologyA919 .
box furnace—a furnace in which, periodically, a load of ware
annealing acid—see acid annealing and annealing.
is introduced; fired, and removed.
anti-scale compound—a preparation that is applied to burning
break out—in dry process enameling, a defect characterized
tools to protect them from scaling in service.
by an area of blisters with well defined boundaries.
back emission—the electrical breakdown of air due to exces-
bright annealing—see Terminology A919.
sive charge build-up in the porcelain enamel powder film
brush—to remove bisque in a definite pattern by means of a
during powder application. This is due to the self-limiting
brush.
characteristic of electrostatic powders.
brush, bolt-hole—see bolt-hole brush.
back ionization—see back emission.
brushing—see brush.
ball mill—in porcelain enamels, a dense, ceramic-lined rotat-
bubble structure—sizeandspatialdistributionofvoidswithin
ing cylinder in which ceramic materials are wet or dry the fired porcelain enamel.
ground, generally using pebbles or porcelain balls as grind-
buck—a special support for ware during the firing of porcelain
ing media. enamel on heavy ware.
base coat—for two coat-one fire application, the thin layer of burning—see firing.
bondingfritappliedfirstandusedtopromoteadherenceafter burning bars, points, or tools—equipment used to suspend or
firing to the metal substrate. support ware during the firing operations.
burning tool mark—a defect in the porcelain enamel appear-
base metal—the metal to which porcelain enamel is applied.
ing on the surface opposite to the point of contact with the
basis metal—see base metal.
supporting burning tool.
basket, pickle—see pickle basket and pickling.
button test—a test designed to determine relative fusibility of
batch smelter—any smelter that operates as a periodic unit,
porcelain enamel frit or powder and so called because the
being charged, fired, and discharged according to a prede-
completed specimens resemble buttons.
termined cycle.
beading—(1) the application of porcelain enamel, usually of a
NOTE 6—See flow button and Test Methods C374.
contrasting color, to the edge or rim of porcelain enameled
cast iron enamel—a porcelain enamel specifically designed
articles.
for application to cast iron.
(2) Removal of excess slip from the edge of dipped ware.
ceramic coating—an inorganic, essentially nonmetallic coat-
(3) In dry processing enameling, a bead of porcelain
ing, on metal.
enamel along the edge of ware.
ceramic colorant—see color oxide.
beading enamel—any of the special porcelain enamels used
ceramic ink—an ink containing a ceramic pigment that
for beading.
develops its color on firing. Also known as stamping,
bisque—a coating of wet-process porcelain enamel that has
screening, or printing ink.
been dried, but not fired.
ceramic-metal coating—a mixture of one or more ceramic
blackboard enamel— see chalkboard enamel.
materials in combination with a metallic phase applied to a
black edging—a black porcelain enamel applied over the
metallic substrate which may or may not require heat
ground coat and exposed in specified areas by brushing the
treatment prior to service. This term may also be used for
cover coat bisque prior to firing (see also edging).
coatings applied to nonmetallic substrates, for example,
black speck—a defect that appears in the fired cover coat as a
graphite.
small dark spot.
cermet coating—see ceramic-metal coating.
blank—the piece cut from metal sheet that is to be used in
chalkboard enamel—a special type of mat porcelain enamel
forming the finished article.
used to provide a writing surface for chalk.
blemish—in dry process enameling, an insignificant imperfec-
chalky or chalked—the condition of a porcelain enameled
tion in the porcelain enamel surface.
surface that has lost its natural gloss and become powdery.
blister—a defect caused by gas evolution consisting of a
charge decay—loss of charge on the deposited powder due to
bubble that forms during fusion and remains when the
electrical leakage.
porcelain enamel solidifies.
charge decay rate—loss of charge per unit of time.
blow-off resistance—the degree to which a deposited layer of
charge retention—the ability of an electrically charged layer
powder resists being blown off by a standard jet of air.
to retain its initial charge.
blue enamel—(1) in dry-process porcelain enameling, an area charge to mass ratio—ratio of the charge on a powder
of enamel coating so thin that it appears blue in color. expressed in coulombs to the mass of the powder expressed
(2) In wet-process enameling, a cover coat applied too in kilograms.
thin to hide the substrate. chipping—fracturing and breaking away of fragments of a
C286–99 (2004)
porcelain enameled surface. copperhead—a defect occurring in sheet metal ground coat
that appears as a small freckle or pimple-like spot, reddish
cleanability—the relative ease with which soils or stains can
brown in color.
be removed from a material.
cover coat—a porcelain enamel finish applied and fused over
NOTE 7—See Test Method C756.
a ground coat or direct to the metal substrate.
covering power—the degree to which a porcelain enamel
cleaner—a solution, usually alkaline, used to remove oil,
coating obscures the underlying surface.
grease, drawing compounds, and loose dirt from metal as a
step in preparing the surface for porcelain enameling. cracking—a defect in the bisque consisting of fractures or
separations.
clear frit—a frit that remains essentially transparent or non-
opaque when processed into a porcelain enamel. crackled—a mottled textural effect in a wet process porcelain
enamel resembling a wrinkled surface.
coating—see ceramic coating and ceramic-metal coating.
crawling—a defect in the porcelain enamel appearing as
coefficient of scatter—the rate of increase of reflectance with
agglomerates or irregularly shaped islands.
thickness at infinitesimal thickness of porcelain enamel over
craze, crazing—a defect appearing as one or more fine cracks
an ideally black backing.
in the porcelain enamel.
NOTE 8—See Test Method C347.
crinkled—a textural effect in a porcelain enamel surface
having the appearance of fine wrinkles or ridges.
cold-rolled steel—a low-carbon, cold-reduced and annealed
crossbend test—a test in which fired or bisque porcelain
sheet steel.
enamel panels are progressively distorted by bending to
color oxide—a material used to impart color to a porcelain
determine the resistance of the coating to cracking.
enamel.
cup gun—aspraygunwithafluidcontainerasanintegralpart.
colored frit—a frit containing a colorant in order to produce a
cupping—the pouring of slip over areas of a part during
strong color in the porcelain enamel.
draining to produce uniform application.
comb-rack—(1) a burning tool shaped like a comb used for
curling—a defect similar to crawling.
supporting ware during firing.
curtains—a defect in sheet steel ground coatings characterized
(2)Acomb-like tool for supporting ware during the metal by a draped pattern of darkened areas that are sometimes
blistered. May also appear in cover coats applied over the
pickling operation.
ground coat or direct-on.
comeback—the time required for a box furnace to return to
decarburized enameling steel—aspecialtypeofsteelsheetof
temperature after the introduction of a load of ware.
extremely low carbon content, suitable for porcelain enamel
cone-screen test—a method for testing fineness of enamel
cover coat application direct to the metal (Type I of
with a cone-shaped sieve. (see also screen test)
Specification A424).
consistency—the properties of a slip that control its draining,
decarburized steel— see decarburized enameling steel.
flowing, and spraying behavior.
decking—the multiple layer loading of ware for firing.
continuity of coating—thedegreetowhichaporcelainenamel
de-enameling—theremovalofporcelainenamelfromthebase
or ceramic coating is free of defects, such as bare spots,
metal.
boiling, blisters or copperheads, that could reduce its pro-
tective properties. deflocculating—the thinning of the consistency of a slip by
adding a suitable electrolyte.
NOTE 9—See Test Method C743.
delayed fishscaling—a fishscaling defect that occurs after the
final porcelain enamel processing (see also fishscaling).
continuous cleaning (coating)—a term describing a type of
devitrification—asurfacedefectmanifestedbylossofglossas
porcelain enamel designed to provide the continuous re-
moval, at normal use temperatures, of food soils accumu- a result of crystallization.
lated on the interior surfaces of ovens. dimple—a shallow depression in the porcelain enamel, some-
continuous furnace—a furnace into which ware is fed con- times a defect.
tinuously and through which it progresses during firing. dipping—the process of coating a metal shape by immersion
in slip, removal, and draining. In dry process enameling, the
continuous smelter—a type of smelter into which the raw mix
is fed continuously and from which the molten product is method of coating by immersing the heated metal shape for
a short time in powdered frit.
discharged continuously.
contrast ratio—the ratio of the reflectance of a coating over dipping weight—see pick-up.
black backing to its reflectance over a backing of reflectance direct fire—a method of maturing porcelain enamel wherein
of 0.80 (80 percent).
the products of combustion come in contact with the ware.
direct-on—see cover coat.
NOTE 10—See Test Method C347.
double draining—a defect evidenced by flowing of the slip on
cooling zone—that part of the continuous furnace in which the theware,whichoccursafteritappearsthatdraininghasbeen
ware is allowed to cool after firing. completed.
copper enamel—a porcelain enamel specifically designed for double-face ware—ware that has a finish coat on both
application to copper. surfaces.
C286–99 (2004)
draining—the part of the dipping or flowcoating process in enamel, jewelers’— see jewelers’ enamel.
which the excess s
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