ASTM C286-99(2009)

NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.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 2009)
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 Scatter
of White Porcelain Enamels (Withdrawn 1990)
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 Test Method forAlkali Resistance of Porcelain Enam-
els
1.3 Hyphenated words, double words, or phrases are listed
alphabetically under the first word; additional important words C633 Test Method for Adhesion or Cohesion Strength of
Thermal Spray Coatings
are cross-referenced.
C743 Test Method for Continuity of Porcelain Enamel
1.4 When a word or phrase, listed as a synonym, is not
Coatings
separately defined, the defined word or phrase is the accepted
C756 Test Method for Cleanability of Surface Finishes
or preferred form.
3. Terminology
2. Referenced Documents
2.1 ASTM Standards:
abrasion resistance—the degree to which a porcelain enamel
A424 SpecificationforSteel,Sheet,forPorcelainEnameling
will resist attack by abrasive materials.
A919 Terminology Relating to Heat Treatment of Metals
NOTE 1—See Test Methods C448.
(Withdrawn 1999)
C282 Test Method for Acid Resistance of Porcelain Enam-
acid annealing—an annealing process in which ferrous metal
els(Citric Acid Spot Test)
shapes are coated with acid before and in conjunction with
C283 Test Methods for Resistance of Porcelain Enameled
the annealing.
Utensils to Boiling Acid
C285 Test Methods for Sieve Analysis of Wet-Milled and acid resistance—the degree to which a porcelain enamel will
Dry-Milled Porcelain Enamel resist attack by acids.
C313 Method of Test for Adherence of Porcelain Enamel
3 NOTE 2—See Test Method C283 and Test Method C282.
and Ceramic Coatings to Sheet Metal (Withdrawn 1989)
C314 Test Method for Flatness of Porcelain Enameled Pan-
adherence—(1) the degree of adhesion of a porcelain enamel
els (Withdrawn 1979)
or other ceramic coating to a metal substrate.
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
Metallic and Inorganic Coatings and is the direct responsibility of Subcommittee
aging—thestoringofporcelainenamelslipsorpowdersbefore
B08.12 on Materials for Porcelain Enamel and Ceramic-Metal Systems.
use. The change occurring in slips or powders with the lapse
Current edition approved Sept. 1, 2009. Published January 2010. Originally
approved in 1951. Last previous edition approved in 2004 as C286–99(2004). DOI:
of time.
10.1520/C0286-99R09.
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
air atomizing—air used to atomize powder and to control
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
powder/air mix and powder cloud density.
Standards volume information, refer to the standard’s Document Summary page on
the ASTM website.
air fluidizer—air used to impart fluid-like properties to pow-
The last approved version of this historical standard is referenced on
www.astm.org. der via a fluid bed.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
C286 − 99 (2009)
alkali resistance—for porcelain enamels, the degree to which blemish—in dry process enameling, an insignificant imperfec-
a porcelain enamel will resist attack by aqueous alkaline tion in the porcelain enamel surface.
solutions.
blister—a defect caused by gas evolution consisting of a
NOTE 5—See Test Method C614. bubble that forms during fusion and remains when the
porcelain enamel solidifies.
alligator hide—a defect characterized by an extreme rough-
ness of the porcelain enamel surface: a severe case of orange
blow-off resistance—the degree to which a deposited layer of
peel. powder resists being blown off by a standard jet of air.
aluminum enamel—a porcelain enamel specifically designed blue enamel—(1) in dry-process porcelain enameling, an area
for application to aluminum. of enamel coating so thin that it appears blue in color.
(2) In wet-process enameling, a cover coat applied too
annealing—see Terminology A919.
thin to hide the substrate.
annealing acid—see acid annealing and annealing.
boiling—a defect visible in the fired porcelain enamel caused
anti-scale compound—a preparation that is applied to burning
by gas evolution which results in the formation of blisters,
tools to protect them from scaling in service.
pinholes, black specks, dimples, or spongy surface.
back emission—the electrical breakdown of air due to exces-
bolt-hole brush—a special round brush used to remove
sive charge build-up in the porcelain enamel powder film
porcelain enamel bisque from in and around small openings
during powder application. This is due to the self-limiting
in the ware.
characteristic of electrostatic powders.
bond—see adherence.
back ionization—see back emission.
box furnace—a furnace in which, periodically, a load of ware
ball mill—in porcelain enamels, a dense, ceramic-lined rotat-
is introduced; fired, and removed.
ing cylinder in which ceramic materials are wet or dry
ground, generally using pebbles or porcelain balls as grind-
break out—in dry process enameling, a defect characterized
ing media.
by an area of blisters with well defined boundaries.
base coat—for two coat-one fire application, the thin layer of
bright annealing—see Terminology A919.
bondingfritappliedfirstandusedtopromoteadherenceafter
brush—to remove bisque in a definite pattern by means of a
firing to the metal substrate.
brush.
base metal—the metal to which porcelain enamel is applied.
brush, bolt-hole—see bolt-hole brush.
brushing—see brush.
basis metal—see base metal.
bubble structure—sizeandspatialdistributionofvoidswithin
basket, pickle—see pickle basket and pickling.
the fired porcelain enamel.
batch smelter—any smelter that operates as a periodic unit,
buck—a special support for ware during the firing of porcelain
being charged, fired, and discharged according to a prede-
enamel on heavy ware.
termined cycle.
burning—see firing.
beading—(1) the application of porcelain enamel, usually of a
burning bars, points, or tools—equipment used to suspend or
contrasting color, to the edge or rim of porcelain enameled
support ware during the firing operations.
articles.
(2) Removal of excess slip from the edge of dipped ware.
burning tool mark—a defect in the porcelain enamel appear-
(3) In dry processing enameling, a bead of porcelain
ing on the surface opposite to the point of contact with the
enamel along the edge of ware.
supporting burning tool.
beading enamel—any of the special porcelain enamels used
button test—a test designed to determine relative fusibility of
for beading.
porcelain enamel frit or powder and so called because the
completed specimens resemble buttons.
bisque—a coating of wet-process porcelain enamel that has
been dried, but not fired.
NOTE 6—See flow button and Test Methods C374.
blackboard enamel— see chalkboard enamel.
cast iron enamel—a porcelain enamel specifically designed
black edging—a black porcelain enamel applied over the for application to cast iron.
ground coat and exposed in specified areas by brushing the
ceramic coating—an inorganic, essentially nonmetallic coat-
cover coat bisque prior to firing (see also edging).
ing, on metal.
black speck—a defect that appears in the fired cover coat as a
ceramic colorant—see color oxide.
small dark spot.
ceramic ink—an ink containing a ceramic pigment that
blank—the piece cut from metal sheet that is to be used in develops its color on firing. Also known as stamping,
forming the finished article. screening, or printing ink.
C286 − 99 (2009)
ceramic-metal coating—a mixture of one or more ceramic consistency—the properties of a slip that control its draining,
materials in combination with a metallic phase applied to a flowing, and spraying behavior.
metallic substrate which may or may not require heat
continuity of coating—thedegreetowhichaporcelainenamel
treatment prior to service. This term may also be used for
or ceramic coating is free of defects, such as bare spots,
coatings applied to nonmetallic substrates, for example,
boiling, blisters or copperheads, that could reduce its pro-
graphite.
tective properties.
cermet coating—see ceramic-metal coating.
NOTE 9—See Test Method C743.
chalkboard enamel—a special type of mat porcelain enamel
continuous cleaning (coating)—a term describing a type of
used to provide a writing surface for chalk.
porcelain enamel designed to provide the continuous re-
chalky or chalked—the condition of a porcelain enameled
moval, at normal use temperatures, of food soils accumu-
surface that has lost its natural gloss and become powdery.
lated on the interior surfaces of ovens.
charge decay—loss of charge on the deposited powder due to
continuous furnace—a furnace into which ware is fed con-
electrical leakage.
tinuously and through which it progresses during firing.
charge decay rate—loss of charge per unit of time.
continuous smelter—a type of smelter into which the raw mix
is fed continuously and from which the molten product is
charge retention—the ability of an electrically charged layer
discharged continuously.
to retain its initial charge.
contrast ratio—the ratio of the reflectance of a coating over
charge to mass ratio—ratio of the charge on a powder
black backing to its reflectance over a backing of reflectance
expressed in coulombs to the mass of the powder expressed
of 0.80 (80 percent).
in kilograms.
NOTE 10—See Test Method C347.
chipping—fracturing and breaking away of fragments of a
porcelain enameled surface.
cooling zone—that part of the continuous furnace in which the
ware is allowed to cool after firing.
cleanability—the relative ease with which soils or stains can
be removed from a material.
copper enamel—a porcelain enamel specifically designed for
application to copper.
NOTE 7—See Test Method C756.
copperhead—a defect occurring in sheet metal ground coat
cleaner—a solution, usually alkaline, used to remove oil,
that appears as a small freckle or pimple-like spot, reddish
grease, drawing compounds, and loose dirt from metal as a
brown in color.
step in preparing the surface for porcelain enameling.
cover coat—a porcelain enamel finish applied and fused over
clear frit—a frit that remains essentially transparent or non-
a ground coat or direct to the metal substrate.
opaque when processed into a porcelain enamel.
covering power—the degree to which a porcelain enamel
coating—see ceramic coating and ceramic-metal coating.
coating obscures the underlying surface.
coefficient of scatter—the rate of increase of reflectance with
thickness at infinitesimal thickness of porcelain enamel over
cracking—a defect in the bisque consisting of fractures or
an ideally black backing.
separations.
NOTE 8—See Test Method C347.
crackled—a mottled textural effect in a wet process porcelain
cold-rolled steel—a low-carbon, cold-reduced and annealed enamel resembling a wrinkled surface.
sheet steel.
crawling—a defect in the porcelain enamel appearing as
agglomerates or irregularly shaped islands.
color oxide—a material used to impart color to a porcelain
enamel.
craze, crazing—a defect appearing as one or more fine cracks
in the porcelain enamel.
colored frit—a frit containing a colorant in order to produce a
strong color in the porcelain enamel.
crinkled—a textural effect in a porcelain enamel surface
having the appearance of fine wrinkles or ridges.
comb-rack—(1) a burning tool shaped like a comb used for
supporting ware during firing.
crossbend test—a test in which fired or bisque porcelain
enamel panels are progressively distorted by bending to
(2)Acomb-like tool for supporting ware during the metal
determine the resistance of the coating to cracking.
pickling operation.
cup gun—aspraygunwithafluidcontainerasanintegralpart.
comeback—the time required for a box furnace to return to
temperature after the introduction of a load of ware. cupping—the pouring of slip over areas of a part during
draining to produce uniform application.
cone-screen test—a method for testing fineness of enamel
with a cone-shaped sieve. (see also screen test) curling—a defect similar to crawling.
C286 − 99 (2009)
curtains—a defect in sheet steel ground coatings characterized dry process enameling—a porcelain enameling process in
by a draped pattern of darkened areas that are sometimes which the metal article is heated to a temperature above the
blistered. May also appear in cover coats applied over the maturing temperature of the coating (usually 1600 to
ground coat or direct-on. 1750°F, (approximately 870 to 955°C)), the coating materi-
als applied to the hot metal as a dry powder, and fired.
decarburized enameling steel—aspecialtypeofsteelsheetof
dry spray—a defect confined to sprayed ware manifesting
extremely low carbon content, suitable for porcelain enamel
cover coat application direct to the metal (Type I of itself in the fired porcelain enamel as a rough, sandy texture.
Specification A424).
dry weight—the weight per unit area of the bisque.
decarburized steel— see decarburized enameling steel.
dust coat—a relatively thin, sprayed coating of slip.
decking—the multiple layer loading of ware for firing.
dusting—(1) In dry-process enameling, see dredging.
de-enameling—theremovalofporcelainenamelfromthebase
(2) A spraying defect characterized by a piling up of
metal.
almost dry slip in confined areas.
(3) The removal of extraneous material from the bisque
deflocculating—the thinning of the consistency of a slip by
before firing.
adding a suitable electrolyte.
(4) See dry spray.
delayed fishscaling—a fishscaling defect that occurs after the
edging—(1) the process of removing bisque from the edge of
final porcelain enamel processing (see also fishscaling).
a piece o
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