1、Designation: A 644 09aStandard Terminology Relating toIron Castings1This standard is issued under the fixed designation A 644; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revision. A number in parentheses indic
2、ates the year of last reapproval. Asuperscript 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.ausferrite, na cast iron matrix microstructure, produced bya controlled thermal process, whic
3、h consists of predomi-nantly acicular ferrite and high carbon austenite. (Seeaustempered ductile iron.)austempered ductile iron, na ductile cast iron that has beenproduced by a controlled thermal process which results in amatrix microstructure consisting of predominately acicularferrite and high car
4、bon austenite.austenitize, vtto convert the matrix of a ferrous alloy toaustenite by heating above the transformation temperature.batch, nthe component raw materials properly weighed,proportioned, and mixed for delivery to a processing unit.Also, the product output from a processing unit in whichthe
5、re is essentially no product output until all componentmaterials are charged and processed.brittle fracture, nfracture that occurs without appreciableplastic deformation of the material.brittle fracture area, nThe fraction or percent of thefracture surface that formed by brittle fracture. (Whenobser
6、ved with no or low magnification, brittle fractureappears whiter and shinier than ductile fracture.)capability index (Cp), nfor a stable process, the specifica-tion range divided by six times the standard deviation.Cp5USL 2 LSL!6 3 scapability index (Cpk), nfor a stable process, the smaller ofthe up
7、per capability index (CPU) or the lower capabilityindex (CPL).carbide, primary, ncarbide precipitated in cast iron duringsolidification.cast iron, na generic term for a series of alloys primarily ofiron, carbon, and silicon in which the carbon is in excess ofthe amount which can be retained in solid
8、 solution inaustenite at the eutectic temperature.cementite, na very hard and brittle compound of iron andcarbon corresponding to the empirical formula Fe3C, com-monly known as iron carbide.cementite, primary, ncementite precipitated in cast ironduring solidification. Also known as primary carbide.
9、(Seecementite.)certification, nA document supplied by the maker or manu-facturer of a product which testifies to the factuality or truthof statements made that the requirements of a productstandard have been met.chill, nan object, usually metal, imbedded in a portion of themold to accelerate the loc
10、al rate of heat removal from themetal being cast.chill, vto accelerate the freezing rate of cast iron, usually ina localized region, to refine the graphite structure or causeformation of primary carbides.chill, microstructural, na localized region of primary car-bides in a casting made from a cast i
11、ron that would normallysolidify free of primary carbides.chilled iron, na cast iron that would normally solidify free ofprimary carbide which is purposely caused to solidify aswhite cast iron, locally or entirely, by accelerated pacted graphite iron, na cast iron that has been treatedin the liquid s
12、tate so as to cause its graphitic carbon to occurin the compacted graphite shape in the as-cast condition.(See graphite, compacted and graphite, spheroidal.)compound, nan intimate mixture of all the ingredientsnecessary for a finished material or pression gasket, na gasket designed to be used pressi
13、on seal, na seal that is attained by a compressiveforce on the sealing material.confidence level, nthe probability, or expected percent of thetimes, that the selected percent (P %) of the actual popula-tion lies within the tolerance interval calculated from thedata sample.direct reduced iron, niron
14、ores that have been reduced toessentially metallic iron by heat and reducing agents, butwithout melting, and processed into suitable shapes (typi-cally pellets) for use as a charge material in a meltingoperation.1This terminology is under the jurisdiction of ASTM Committee A04 on IronCastings and is
15、 the direct responsibility of Subcommittee A04.91 on EditorialMatters and Nomenclature.Current edition approved July 1, 2009. Published July 2009. Originally approvedin 1971. Last previous edition approved in 2009 as A 644 - 09.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West
16、Conshohocken, PA 19428-2959, United States.dual metal, ntwo metals of different composition that arefusion bonded at all interfacial surfaces by casting metal ofone composition against metal of a second composition.ductile fracture, nfracture that occurs with appreciableplastic deformation of the ma
17、terial.ductile fracture area, nThe fraction or percent of thefracture surface that formed by ductile fracture. (Whenobserved with no or low magnification, ductile fractureappears grayer and duller than brittle fracture.)ductile iron, na cast iron that has been treated in the liquidstate so as to cau
18、se substantially all of its graphitic carbon tooccur as spheroids or nodules in the as-cast condition.durometer(1) an instrument for measuring the hardness ofrubber-like materials. (2) a term used to identify the relativehardness of rubber-like materials, for example: “low durom-eter” (relatively so
19、ft) or “high durometer” (relatively hard).elastomer, na macromolecular material that returns rapidlyto approximately its original dimensions and shape aftersubstantial deformation by a weak force and release of theforce.DISCUSSION(a) Elastomers are divided into two major polymersystems: thermoset an
20、d thermoplastic. (b) In standards for rubber, theword elastomer is not to be used interchangeably for the term “rubber”.elongation, nextension produced by a tensile stress.ferritize, vtto increase the quantity of ferrite in the matrix ofa ferrous casting through an appropriate heat treatment.ferriti
21、zing anneal, nthe process of producing a predomi-nantly ferritic matrix in cast iron through an appropriate heattreatment.gasket, nany preformed, deformable device designed to beplaced between two adjoining parts to provide a seal.graphite, compacted, na graphite shape that is intermediatebetween fl
22、ake graphite and nodular graphite that typicallyappears in a polished section as thick flakes with blunt(compacted) ends.graphite flake, nan irregularly shaped particle of graphite,usually appearing in a polished section as curved plates, suchas found in gray cast irons.graphite, nodular, nspheroida
23、l shaped graphite typicallyfound in ductile irons and compact clusters of graphitetypically found in malleable irons. (See graphite, spheroi-dal, and temper carbon.)graphite, primary, ngraphite precipitated in cast iron duringsolidification.graphite rosette, narrangement of graphite flakes in whicht
24、he flakes extend radially from centers of crystallization ingray cast iron.graphite, spheroidal, nspheroidal shaped graphite having apolycrystalline radial structure, usually found in ductile ironand to a controlled, limited extent in compacted graphiteiron.graphitize, vtto precipitate graphite in a
25、n iron-carbon alloy.gray iron, ncast iron that has a relatively large proportion ofthe graphitic carbon present in the form of flake graphite.The metal has a gray fracture.hardness, nthe resistance to indentation as measured underspecified conditions.heat, nthe total molten metal output from a singl
26、e heating ina batch melting process or the total molten metal output fromessentially a single heating in a continuous melting operationusing basically constant charge and processing conditionsand targeted at a fixed metal chemistry at the furnace spout.A heat can also be defined as a fixed time peri
27、od for acontinuous melting operation provided that it is shorter thanthe time period covered by the above definition.hydrostatic pressure, na state of stress in which all theprincipal stresses are equal (and there is no shear stress), asin a liquid at rest; the product of the unit weight of the liqu
28、idand the difference in elevation between the given point andthe free liquid elevation.inoculated iron, ncast iron, either liquid or solid, to whichone or more inoculating alloys have been added while theiron was in the molten state.inoculated iron, fully, ncast iron, either liquid or solid, towhich
29、 all molten metal additions, including all inoculatingalloys, have been added.inoculating alloy, nan alloy added to molten iron for theprinciple purpose of nucleating a primary phase such asgraphite. Inoculating alloys are frequently used to avoid theformation of primary carbide by enhancing the nuc
30、leation ofgraphite.lot, na finite quantity of a given product manufactured underproduction conditions that are considered uniform.lower capability index (CPL), nthe difference between thesample mean ( x) and the lower specification limit divided bythree times the standard deviation.CPL 5x 2 LSL!3 3
31、slower specification limit (LSL), nthe lowest specifiedvalue.M, nthe number of standard deviations, mutually concurredby the supplier and purchaser, to be used for calculations ofstatistical conformance to such items as minimums, maxi-mums, specification ranges, and process capability indices.DISCUS
32、SIONM values of three or less were used in establishinginitial ASTM specification limits; higher values of M result in reducedallowable variability for actual values when the property of interest isbounded on both sides; in the case of a minimum or maximum, a highvalue of M can result in the need fo
33、r excessively high or low meanproperty values ( x).malleable, ferritic, na ferrous alloy that is cast as white ironbut which is converted by an appropriate heat treatment to amicrostructure of temper carbon embedded in a ferriticmatrix essentially free of pearlite and carbide.malleable iron, na cast
34、 iron of such composition that itsolidifies as white iron, which upon proper heat treatment isconverted to a metallic matrix with nodules of tempercarbon.malleable, pearlitic, na ferrous alloy that is cast as whiteiron but which is converted by an appropriate heat treatmentto a microstructure of tem
35、per carbon embedded in a matrixcontaining a controlled quantity, form, and distribution ofpearlite or tempered martensite.malleableize, vtto convert white iron into malleable ironthrough an appropriate graphitizing heat treatment.A 644 09a2manufacturer, castings, nthe entity that directly controlsth
36、e melting and pouring of metal, and casting it into aproduct covered by the standard.maximum (non-statistical), nthe highest acceptable actualtest result; any valid individual test result above the maxi-mum is cause for rejection of the component or material lotbeing tested.All xi#Maximum 5 USLmaxim
37、um (statistical), nthe highest acceptable statisticaltest result; for compliance, the sample mean ( x) plus Mstandard deviations(s), where M is a matter of agreementbetween the supplier and purchaser, must be less than, orequal to, the upper specification limit.x 1 M 3 s #Maximum 5 USLDISCUSSION1A n
38、ormal data distribution is assumed for thepopulation from which the data sample was drawn.DISCUSSION2 M values of three or less were used in establishinginitialASTM specifications limits. Higher values of M result in reducedallowable variability for actual values when the property of interest isboun
39、ded on both sides. In the case of a minimum or maximum, a highvalue of M can result in the need for excessively high or low meanproperty values ( x).mean ( x), nthe sum of the individual data points (xs)divided by the number of data points ( n).x 5(xinmelt, nthe total molten metal produced in a sing
40、le heat.merchant pig iron, npig iron produced for commercial saleto foundries.minimum (non-statistical), nthe lowest acceptable actualtest result; any valid individual test result below the mini-mum is cause for rejection of the component or material lotbeing tested.All xi$Minimum 5 LSLminimum (stat
41、istical), nthe lowest acceptable statistical testresult; for compliance, the sample mean ( x) minus Mstandard deviation(s), where M is a matter of agreementbetween the supplier and purchaser, must be greater than, orequal to, the lower specification limit (LSL).x 2 M 3 s $Minimum 5 LSLDISCUSSION1A n
42、ormal data distribution is assumed for thepopulation from which the data sample was drawn.DISCUSSION2M values of three or less were used in establishinginitial ASTM specification limits; higher values of M result in reducedallowable variability for actual values when the property of interest isbound
43、ed on both sides; in the case of a minimum or maximum, a highvalue of M can result in the need for excessively high or low meanproperty values ( x).mottled iron, na cast iron containing a mixed structure ofgray iron and white iron of variable proportions.The fracturehas a mottled appearance.nodular
44、graphite, ngraphite in the form of nodules orspheroids in iron castings.nodularity, nthe volumetric proportion of spheroidal ornodular graphite to total graphite in a ductile iron or acompacted graphite iron matrix (see Test Method A 247, forEvaluating the Microstructure of Graphite in IronCastings,
45、2Types I and II).nodularity, degree of, nthe volumetric proportion of sphe-roidal or nodular graphite to total graphite in a ductile ironmatrix (see Test Method A 247, Types I and II).nodulizing alloy, nan alloy added to molten iron for theprimary purpose of causing the formation of spheroidalgraphi
46、te during solidification.pig iron, nthe high carbon iron product obtained by thereduction of iron ores, typically in a blast furnace or anelectric furnace, and cast into uniform shapes (pigs) havingphysical and chemical characteristics suitable for end use asfoundry melting stock.range, data, nthe a
47、bsolute value of the difference betweenthe highest and lowest values in a set of data.range, specification (non-statistical), nthe absolute valueof the difference between the highest (USL) and lowest(LSL) specified values; for compliance with a non-statisticalrange, each valid individual test result
48、 must lie at, or within,the specification limits.LSL#All xi#USLrange, specification (statistical), nthe absolute value of thedifference between the highest (USL) and lowest (LSL)specified values; for compliance with a statistical range, allcalculated values from the mean ( x) minus M times thestanda
49、rd deviation(s) to the mean plus M times the standarddeviation, where M is a matter of agreement between thesupplier and purchaser, must not lie outside of the specifi-cation limits.LSL#x 2 M 3 s and x 1 M 3 s#USLDISCUSSION1A normal data distribution is assumed for thepopulation from which the data sample was drawn.DISCUSSION2M values of three or less were used in establishinginitial ASTM specification limits; higher values of M result in reduc
