ASTM C448-88(2021)

Standard Test Methods for Abrasion Resistance of Porcelain Enamels

SIGNIFICANCE AND USE
4.1 When a porcelain enamel is first subjected to abrasion of the type involved in these tests, the rate of wear or attrition is relatively low. As the enamel is subjected to continued abrasion, the rate of wear increases until it reaches a steady value. Thereafter, the rate of wear remains almost constant until the enamel is penetrated and the underlying ground coat or metal exposed. The abrasion that occurs during the period of increasing rate-of-weight loss is defined as surface abrasion and results in reduced gloss and cleanability with high-gloss enamels and a modification of color, appearance, or surface texture, or combination thereof with low-gloss enamels. The abrasion that occurs during the period of steady rate-of-weight loss is defined as subsurface abrasion and results in the destruction of the continuity of the coating. These two types of abrasion are not necessarily proportional, and since it is desirable to be able to determine the resistance of porcelain enamel to both types of abrasion, it is necessary to deal with each one separately.
SCOPE
1.1 These test methods cover determination of the resistance of porcelain enamels to surface abrasion and subsurface abrasion.  
1.2 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.  
1.3 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

General Information

• Status: Published
• Publication Date: 31-Mar-2021
• ICS: 25.220.50 - Enamels
• Technical Committee: B08 - Metallic and Inorganic Coatings
• Drafting Committee: B08.12 - Materials for Porcelain Enamel and Ceramic-Metal Systems

Standards Content (Sample)

This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the
Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
Designation: C448 − 88 (Reapproved 2021)
Standard Test Methods for
1
Abrasion Resistance of Porcelain Enamels
This standard is issued under the fixed designation C448; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision.Anumber in parentheses indicates the year of last reapproval.A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
INTRODUCTION
Thistestisameansofquantifyingtheabrasionresistanceofporcelainenamelsthroughsteady-state
subsurfaceabrasivewearwithstainlesssteelballbearings.Achangeinglossorweightlossisreported
that can, through further evaluation, be correlated to the service life of the enameled ware.
1. Scope theoriginalspecularglossthatisretainedaftertreatmentasthe
surface abrasion index.
1.1 Thesetestmethodscoverdeterminationoftheresistance
of porcelain enamels to surface abrasion and subsurface
3.2 The second test is intended for the determination of the
abrasion.
resistance to surface abrasion of porcelain enamels for which
1.2 This standard does not purport to address all of the the unabraded 45° specular gloss is 30 gloss units or less. It
safety concerns, if any, associated with its use. It is the consists of determining the weight loss by a specified abrasive
responsibility of the user of this standard to establish appro-
treatment and multiplying this weight loss by an adjustment
priate safety, health, and environmental practices and deter-
factor associated with each abrasive tester, lot of abrasive, and
mine the applicability of regulatory limitations prior to use.
lot of calibrated plate glass standards used. The adjusted
1.3 This international standard was developed in accor-
weight loss is taken as an index of resistance to surface
dance with internationally recognized principles on standard-
abrasion.
ization established in the Decision on Principles for the
3.3 The third test is intended for the determination of the
Development of International Standards, Guides and Recom-
resistance of porcelain enamels to subsurface abrasion. It
mendations issued by the World Trade Organization Technical
consists of determining the slope of the linear portion of the
Barriers to Trade (TBT) Committee.
abrasion time-weight loss curve and multiplying by an adjust-
2. Referenced Documents
ment factor associated with each abrasion tester, lot of
2
abrasive, and lot of calibrated plate glass standards used. The
2.1 ASTM Standards:
adjusted slope is taken as an index of resistance to subsurface
C346Test Method for 45-deg Specular Gloss of Ceramic
abrasion.
Materials
3. Summary of Test Methods
4. Significance and Use
3.1 The first of the tests described herein is intended for the
4.1 Whenaporcelainenamelisfirstsubjectedtoabrasionof
determinationoftheresistancetosurfaceabrasionofporcelain
the type involved in these tests, the rate of wear or attrition is
enamels for which the unabraded 45° specular gloss is more
relatively low. As the enamel is subjected to continued
than 30 gloss units. It consists essentially of measuring the
abrasion, the rate of wear increases until it reaches a steady
specular gloss of the specimens before and after a specified
value. Thereafter, the rate of wear remains almost constant
abrasive treatment of the surface, and taking the percentage of
until the enamel is penetrated and the underlying ground coat
ormetalexposed.Theabrasionthatoccursduringtheperiodof
1
increasing rate-of-weight loss is defined as surface abrasion
These test methods are under the jurisdiction of ASTM Committee B08 on
Metallic and Inorganic Coatings and are the direct responsibility of Subcommittee
and results in reduced gloss and cleanability with high-gloss
B08.12 on Materials for Porcelain Enamel and Ceramic-Metal Systems.
enamels and a modification of color, appearance, or surface
Current edition approved April 1, 2021. Published May 2021. Originally
texture, or combination thereof with low-gloss enamels. The
approvedin1959.Lastpreviouseditionapprovedin2016asC448–88(2016).DOI:
10.1520/C0448-88R21.
abrasion that occurs during the period of steady rate-of-weight
2
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
loss is defined as subsurface abrasion and results in the
contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
destruction of the continuity of the coating.These two types of
Standards volume information, refer to the standard’s Document Summary page on
the ASTM website. abrasion are not necessarily proportional, and since it is
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