ASTM A802/A802M-95(2010)
(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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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 Department of Defense.
1. Scope sandandtheresultingmoldorcorestressesduringfillingofthe
mold with liquid steel.
1.1 This practice covers the acceptance criteria for the
2.1.1.2 rat tails, n—long, narrow, linear depressions or
surfaceinspectionofsteelcastingsbyvisualexamination.Four
small steps occurring on a casting surface. Rat tails form as a
levels of acceptance standards are provided.
result of sand expansion and minor buckling of the mold
1.2 Acceptance levels utilize Steel Castings Research and
2 surface during filling of the mold with liquid metal.
Trade Association (SCRATA) graded reference comparators
2.1.1.3 scab, n—a raised, rough area on a casting that
for the visual determination of surface texture, surface rough-
usually consists of a crust of metal covering a layer of sand.
ness, and surface discontinuities described as follows:
Sometimes, a scab consists of a raised, rough area of essen-
Acceptance levels
tially solid metal on the surface of a casting.
A—Surface Texture
2.1.2 external chills:
B—Nonmetallic Inclusions
2.1.2.1 external chills, n—usually metal blocks, or graphite
C—Gas Porosity
and carbon blocks, that are incorporated into the mold to
D—Solidification Discontinuities
locally increase the rate of heat removal during solidification.
E—Sand Expansion Discontinuities
Brackets have the same purpose but represent an integral part
F—Metal Inserts
of the casting. Brackets are produced by providing suitable
G—Thermally Cut Surfaces
cavities in the mold or core. External chills may produce flat
H—Mechanically Prepared Surfaces
spots and edges (raised areas or depressions) on the casting
J—Welded Surfaces
surface. Brackets merely change the casting appearance due to
1.3 Descriptions of terms related to casting discontinuities
their presence. Brackets may be removed or allowed to remain
are in Section 2.
on the casting.
1.4 This standard does not purport to address all of the
2.1.2.2 parting line and core print fins, n—thin projections
safety concerns, if any, associated with its use. It is the
of excess metal at the parting plane between mold halves or
responsibility of the user of this standard to establish appro-
core and mold. Causes are improper closing of the mold,
priate safety and health practices and determine the applica-
insufficient weighting or clamping of the mold for pouring, or
bility of regulatory limitations prior to use.
uneven pattern surfaces at the matching locations. Core print
2. Terminology fins are usually caused by improper dimensions of core prints
ofthepatternorcorebox,byroughplacementofcoresinasoft
2.1 Definitions of Terms Specific to This Standard:
mold, or by inadequately secured cores.
2.1.1 expansion discontinuities:
2.1.3 fusion discontinuities:
2.1.1.1 veins, n—raised, narrow, linear ridges that form
2.1.3.1 wrinkles, n—elongated, smooth depressions of the
upon cracking of the sand mold or core due to expansion of
casting surface, frequently appearing in closely spaced groups.
Wrinkles result from irregularities of the liquid metal flow in
This practice is under the jurisdiction of ASTM Committee A01 on Steel,
the mold cavity, frequently associated with low temperature,
Stainless Steel and Related Alloys and is the direct responsibility of Subcommittee
and are distinguished from the more severe phenomenon of
A01.18 on Castings.
Current edition approved Oct. 1, 2010. Published December 2010. Originally
laps, folds, or cold shuts where the casting surface is actually
approved in 1982. Last previous edition approved in 2006 as A802/
folded over.
A802M – 95 (2006). DOI: 10.1520/A0802_A0802M-95R10.
2 2.1.3.2 laps, folds, and cold shuts, n—interchangeable
Available from The Castings Development Centre, 7 East Bank Road,
terms to describe the appearance of the casting surface that is
Sheffield, UK S2 3PT.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
A802/A802M–95 (2010)
actually folded over. They develop due to low temperature, 2.1.8.1 Ceroxides cause depressions on the surface of the
unfavorable flow conditions caused by oxide films, or combi- casting by displacement of molten metal. Ceroxides consist of
nations thereof. a mixture of low-melting oxides and partially fused sand. The
2.1.3.3 misrun, n—an incompletely formed casting, due to crater-like appearance of the casting surface depression is
only partial filling of the mold cavity when the liquid metal typical.
solidifies prematurely. The resulting casting appearance is
2.1.8.2 Depressions on the casting surface caused by slag
characterized by rounded edges, for a mild degree of misrun.
are similar to those caused by ceroxides. They differ by a more
Irregular, malformed edges of more severe misruns, and not
rounded appearance of the depression and do not exhibit the
fully formed castings, are characteri
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