ASTM A802/A802M-95(2010)e1
(Practice)Standard Practice for Steel Castings, Surface Acceptance Standards, Visual Examination
Standard Practice for Steel Castings, Surface Acceptance Standards, Visual Examination
ABSTRACT
This practice covers the standard acceptance criteria for the determination of surface texture, surface roughness, and surface discontinuities of steel castings by visual examination. The acceptance levels utilize the Steel Castings Research and Trade Association (SCRATA) graded reference comparators described as follows: Level A for surface texture, Level B for nonmetallic inclusions, Level C for gas porosity, Level D for solidification discontinuities, Level E for sand expansion discontinuities, Level F for metal inserts, Level G for thermally cut surfaces, Level H for mechanically prepared surfaces, and Level J for welded surfaces.
SCOPE
1.1 This practice covers the acceptance criteria for the surface inspection of steel castings by visual examination. Four levels of acceptance standards are provided.
1.2 Acceptance levels utilize Steel Castings Research and Trade Association (SCRATA) graded reference comparators for the visual determination of surface texture, surface roughness, and surface discontinuities described as follows:
Acceptance levels
ASurface Texture
BNonmetallic Inclusions
CGas Porosity
DSolidification Discontinuities
ESand Expansion Discontinuities
FMetal Inserts
GThermally Cut Surfaces
HMechanically Prepared Surfaces
JWelded Surfaces
1.3 Descriptions of terms related to casting discontinuities are in Section 2.
1.4 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 and health practices and determine the applicability of regulatory limitations prior to use.
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Standards Content (Sample)
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Designation: A802/A802M − 95(Reapproved 2010)
Standard Practice for
Steel Castings, Surface Acceptance Standards, Visual
Examination
This standard is issued under the fixed designationA802/A802M; 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 U.S. Department of Defense.
ε NOTE—Footnote 2 was editorially corrected in June 2011.
1. Scope 2.1.1.1 veins, n—raised, narrow, linear ridges that form
upon cracking of the sand mold or core due to expansion of
1.1 This practice covers the acceptance criteria for the
sandandtheresultingmoldorcorestressesduringfillingofthe
surfaceinspectionofsteelcastingsbyvisualexamination.Four
mold with liquid steel.
levels of acceptance standards are provided.
2.1.1.2 rat tails, n—long, narrow, linear depressions or
1.2 Acceptance levels utilize Steel Castings Research and
small steps occurring on a casting surface. Rat tails form as a
Trade Association (SCRATA) graded reference comparators
result of sand expansion and minor buckling of the mold
for the visual determination of surface texture, surface
surface during filling of the mold with liquid metal.
roughness, and surface discontinuities described as follows:
2.1.1.3 scab, n—a raised, rough area on a casting that
Acceptance levels
usually consists of a crust of metal covering a layer of sand.
A—Surface Texture
Sometimes, a scab consists of a raised, rough area of essen-
B—Nonmetallic Inclusions
tially solid metal on the surface of a casting.
C—Gas Porosity
2.1.2 external chills:
D—Solidification Discontinuities
2.1.2.1 external chills, n—usually metal blocks, or graphite
E—Sand Expansion Discontinuities
and carbon blocks, that are incorporated into the mold to
F—Metal Inserts
locally increase the rate of heat removal during solidification.
G—Thermally Cut Surfaces
Brackets have the same purpose but represent an integral part
H—Mechanically Prepared Surfaces
of the casting. Brackets are produced by providing suitable
J—Welded Surfaces
cavities in the mold or core. External chills may produce flat
1.3 Descriptions of terms related to casting discontinuities
spots and edges (raised areas or depressions) on the casting
are in Section 2.
surface. Brackets merely change the casting appearance due to
1.4 This standard does not purport to address all of the
their presence. Brackets may be removed or allowed to remain
safety concerns, if any, associated with its use. It is the
on the casting.
responsibility of the user of this standard to establish appro-
2.1.2.2 parting line and core print fins, n—thin projections
priate safety and health practices and determine the applica-
of excess metal at the parting plane between mold halves or
bility of regulatory limitations prior to use.
core and mold. Causes are improper closing of the mold,
insufficient weighting or clamping of the mold for pouring, or
2. Terminology
uneven pattern surfaces at the matching locations. Core print
2.1 Definitions of Terms Specific to This Standard: fins are usually caused by improper dimensions of core prints
2.1.1 expansion discontinuities:
ofthepatternorcorebox,byroughplacementofcoresinasoft
mold, or by inadequately secured cores.
2.1.3 fusion discontinuities:
This practice is under the jurisdiction of ASTM Committee A01 on Steel,
2.1.3.1 wrinkles, n—elongated, smooth depressions of the
Stainless Steel and Related Alloysand is the direct responsibility of Subcommittee
casting surface, frequently appearing in closely spaced groups.
A01.18 on Castings.
Wrinkles result from irregularities of the liquid metal flow in
Current edition approved Oct. 1, 2010. Published December 2010. Originally
approved in 1982. Last previous edition approved in 2006 as A802/
the mold cavity, frequently associated with low temperature,
A802M – 95 (2006). DOI: 10.1520/A0802_A0802M-95R10E01.
and are distinguished from the more severe phenomenon of
Available from Castings Technology International, Advanced Manufacturing
laps, folds, or cold shuts where the casting surface is actually
Park, Brunel Way, Rotherham, S60 5WG, South Yorkshire, England. http://
www.castingstechnology.com. folded over.
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A802/A802M − 95 (2010)
2.1.3.2 laps, folds, and cold shuts, n—interchangeable removed during the cleaning process of pressure blasting.
terms to describe the appearance of the casting surface that is Surface discontinuities left by these inclusions are referred to
actually folded over. They develop due to low temperature, by the inclusion type that caused their formation:
unfavorable flow conditions caused by oxide films, or combi- 2.1.8.1 Ceroxides cause depressions on the surface of the
nations thereof. casting by displacement of molten metal. Ceroxides consist of
2.1.3.3 misrun, n—an incompletely formed casting, due to a mixture of low-melting oxides and partially fused sand. The
only partial filling of the mold cavity when the liquid metal crater-like appearance of the casting surface depression is
solidifies prematurely. The resulting casting appearance is typical.
characterized by rounded edges, for a mild degree of misrun. 2.1.8.2 Depressions on the casting surface caused by slag
Irreg
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