1、Designation: A644 13A644 14Standard Terminology Relating toIron Castings1This standard is issued under the fixed designation A644; 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 i
2、ndicates 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 U.S. Department of Defense.ausferrite, na cast iron matrix microstructure, produced by a controlled thermal pro
3、cess, which consists of predominantlyacicular ferrite and high carbon austenite. (See austempered ductile iron.)austempered ductile iron, na ductile cast iron that has been produced by a controlled thermal process which results in a matrixmicrostructure consisting of predominately acicular ferrite a
4、nd high carbon austenite.austenitize, vtto convert the matrix of a ferrous alloy to austenite by heating above the transformation temperature.batch, nthe component raw materials properly weighed, proportioned, and mixed for delivery to a processing unit. Also, theproduct output from a processing uni
5、t in which there is essentially no product output until all component materials are chargedand processed.brittle fracture, nfracture that occurs without appreciable plastic deformation of the material.brittle fracture area, nThe fraction or percent of the fracture surface that formed by brittle frac
6、ture. (When observed with noor low magnification, brittle fracture appears whiter and shinier than ductile fracture.)capability index (Cp),nfor a stable process, the specification range divided by six times the standard deviation.Cp 5USL2 LSL!63scapability index (Cpk),nfor a stable process, the smal
7、ler of the upper capability index (CPU) or the lower capability index (CPL).carbide, primary, ncarbide precipitated in cast iron during solidification.cast iron, na generic term for a series of alloys primarily of iron, carbon, and silicon in which the carbon is in excess of theamount which can be r
8、etained in solid solution in austenite at the eutectic temperature.cementite, na very hard and brittle compound of iron and carbon corresponding to the empirical formula Fe3C, commonlyknown as iron carbide.cementite, primary, ncementite precipitated in cast iron during solidification.Also known as p
9、rimary carbide. (See cementite.)center stop, nan integral part of the gasket, centered at its axial length, intended to limit the insertion depth of the pipe or fitting,or both, to be coupled.certification, nA document supplied by the maker or manufacturer of a product which testifies to the factual
10、ity or truth ofstatements made that the requirements of a product standard have been met.chill, nan object, usually metal, imbedded in a portion of the mold to accelerate the local rate of heat removal from the metalbeing cast.chill, vto accelerate the freezing rate of cast iron, usually in a locali
11、zed region, to refine the graphite structure or cause formationof primary carbides.chill, microstructural, na localized region of primary carbides in a casting made from a cast iron that would normally solidifyfree of primary carbides.1 This terminology is under the jurisdiction of ASTM Committee A0
12、4 on Iron Castings and is the direct responsibility of Subcommittee A04.91 on Editorial Matters andNomenclature.Current edition approved May 1, 2013Oct. 1, 2014. Published May 2013October 2014. Originally approved in 1971. Last previous edition approved in 20092013 asA644 - 09a.A644 - 13. DOI: 10.15
13、20/A0644-13.10.1520/A0644-14.This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Becauseit may not be technically possible to adequately depict all changes accurately, ASTM recommends
14、 that users consult prior editions as appropriate. In all cases only the current versionof the standard as published by ASTM is to be considered the official document.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States1chilled iron, na ca
15、st iron that would normally solidify free of primary carbide which is purposely caused to solidify as whitecast iron, locally or entirely, by accelerated pacted graphite iron, na cast iron that has been treated in the liquid state so as to cause its graphitic carbon to occur inthe compacted graphite
16、 shape in the as-cast condition. (See graphite, compacted and graphite, spheroidal.)compound, nan intimate mixture of all the ingredients necessary for a finished material or pression gasket, na gasket designed to be used under pression seal, na seal that is attained by a compressive force on the se
17、aling material.confidence level, nthe probability, or expected percent of the times, that the selected percent (P %) of the actual population lieswithin the tolerance interval calculated from the data sample.coupling, nthe complete clamp, shield and gasket assembly.coupling, push-on type, na couplin
18、g utilizing a fixed gasket where assembly of the joint is accomplished without removing theshield.direct reduced iron, niron ores that have been reduced to essentially metallic iron by heat and reducing agents, but withoutmelting, and processed into suitable shapes (typically pellets) for use as a c
19、harge material in a melting operation.dual metal, ntwo metals of different composition that are fusion bonded at all interfacial surfaces by casting metal of onecomposition against metal of a second composition.ductile fracture, nfracture that occurs with appreciable plastic deformation of the mater
20、ial.ductile fracture area, nThe fraction or percent of the fracture surface that formed by ductile fracture. (When observed with noor low magnification, ductile fracture appears grayer and duller than brittle fracture.)ductile iron, na cast iron that has been treated in the liquid state so as to cau
21、se substantially all of its graphitic carbon to occuras spheroids or nodules in the as-cast condition.durometer(1) an instrument for measuring the hardness of rubber-like materials. (2) a term used to identify the relative hardnessof rubber-like materials, for example: “low durometer” (relatively so
22、ft) or “high durometer” (relatively hard).elastomer, na macromolecular material that returns rapidly to approximately its original dimensions and shape after substantialdeformation by a weak force and release of the force.DISCUSSION(a) Elastomers are divided into two major polymer systems: thermoset
23、 and thermoplastic. (b) In standards for rubber, the word elastomer is not to beused interchangeably for the term “rubber”.elastomeric, adjhaving the characteristics of an elastomer.elongation, nextension produced by a tensile stress.ferritize, vtto increase the quantity of ferrite in the matrix of
24、a ferrous casting through an appropriate heat treatment.ferritizing anneal, nthe process of producing a predominantly ferritic matrix in cast iron through an appropriate heat treatment.gasket, nany preformed, deformable device designed to be placed between two adjoining parts to provide a seal.graph
25、ite, compacted, na graphite shape that is intermediate between flake graphite and nodular graphite that typically appearsin 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 pl
26、ates, such as foundin gray cast irons.graphite, nodular, nspheroidal shaped graphite typically found in ductile irons and compact clusters of graphite typically foundin malleable irons. (See graphite, spheroidal , and temper carbon.)graphite, primary, ngraphite precipitated in cast iron during solid
27、ification.graphite rosette, narrangement of graphite flakes in which the flakes extend radially from centers of crystallization in gray castiron.graphite, spheroidal, nspheroidal shaped graphite having a polycrystalline radial structure, usually found in ductile iron and toa controlled, limited exte
28、nt in compacted graphite iron.A644 142graphitize, vtto precipitate graphite in an iron-carbon alloy.gray iron, ncast iron that has a relatively large proportion of the graphitic carbon present in the form of flake graphite. The metalhas a gray fracture.hardness, nthe resistance to indentation as mea
29、sured under specified conditions.heat, nthe total molten metal output from a single heating in a batch melting process or the total molten metal output fromessentially a single heating in a continuous melting operation using basically constant charge and processing conditions andtargeted at a fixed
30、metal chemistry at the furnace spout.Aheat can also be defined as a fixed time period for a continuous meltingoperation provided that it is shorter than the time period covered by the above definition.hydrostatic pressure, na state of stress in which all the principal stresses are equal (and there i
31、s no shear stress), as in a liquidat rest; the product of the unit weight of the liquid and the difference in elevation between the given point and the free liquidelevation.inoculated iron, ncast iron, either liquid or solid, to which one or more inoculating alloys have been added while the iron was
32、in the molten state.inoculated iron, fully, ncast iron, either liquid or solid, to which all molten metal additions, including all inoculating alloys, havebeen added.inoculating alloy, nan alloy added to molten iron for the principle purpose of nucleating a primary phase such as graphite.Inoculating
33、 alloys are frequently used to avoid the formation of primary carbide by enhancing the nucleation of graphite.lot, na finite quantity of a given product manufactured under production conditions that are considered uniform.lower capability index (CPL), nthe difference between the sample mean (x) and
34、the lower specification limit divided by threetimes the standard deviation.CPL5x 2 LSL!33slower specification limit (LSL), n the lowest specified value.M, nthe number of standard deviations, mutually concurred by the supplier and purchaser, to be used for calculations ofstatistical conformance to su
35、ch items as minimums, maximums, specification ranges, and process capability indices.DISCUSSIONM values of three or less were used in establishing initial ASTM specification limits; higher values of M result in reduced allowable variability foractual values when the property of interest is bounded o
36、n both sides; in the case of a minimum or maximum, a high value of M can result in the needfor excessively high or low mean property values (x ).malleable, ferritic, na ferrous alloy that is cast as white iron but which is converted by an appropriate heat treatment to amicrostructure of temper carbo
37、n embedded in a ferritic matrix essentially free of pearlite and carbide.malleable iron, na cast iron of such composition that it solidifies as white iron, which upon proper heat treatment is convertedto a metallic matrix with nodules of temper carbon.malleable, pearlitic, na ferrous alloy that is c
38、ast as white iron but which is converted by an appropriate heat treatment to amicrostructure of temper carbon embedded in a matrix containing a controlled quantity, form, and distribution of pearlite ortempered martensite.malleableize, vtto convert white iron into malleable iron through an appropria
39、te graphitizing heat treatment.manufacturer, castings, nthe entity that directly controls the melting and pouring of metal, and casting it into a product coveredby the standard.manufacturer, clamp assembly and shield, nthe entity that attaches the clamp assembly to the shield.manufacturer, coupling,
40、 nthe entity that assembles the gasket with the clamp and shield assembly.manufacturer, gasket, nthe entity that molds the gaskets.maximum (non-statistical), nthe highest acceptable actual test result; any valid individual test result above the maximum iscause for rejection of the component or mater
41、ial lot being tested.All xi#Maximum5USLA644 143maximum (statistical), nthe highest acceptable statistical test result; for compliance, the sample mean (x) plus M standarddeviations(s), where M is a matter of agreement between the supplier and purchaser, must be less than, or equal to, the upperspeci
42、fication limit.x1M 3s#Maximum5USLDISCUSSION1A normal data distribution is assumed for the population from which the data sample was drawn.DISCUSSION2M values of three or less were used in establishing initial ASTM specifications limits. Higher values of Mresult in reduced allowable variabilityfor ac
43、tual values when the property of interest is bounded on both sides. In the case of a minimum or maximum, a high value of M can result in theneed for excessively high or low mean property values (x).mean (x ),nthe sum of the individual data points (xs) divided by the number of data points ( n).x 5(xi
44、nmelt, nthe total molten metal produced in a single heat.merchant pig iron, npig iron produced for commercial sale to foundries.minimum (non-statistical), nthe lowest acceptable actual test result; any valid individual test result below the minimum is causefor rejection of the component or material
45、lot being tested.All xi$Minimum5LSLminimum (statistical), nthe lowest acceptable statistical test result; for compliance, the sample mean (x) minus M standarddeviation(s), where M is a matter of agreement between the supplier and purchaser, must be greater than, or equal to, the lowerspecification l
46、imit (LSL).x 2M 3s$Minimum5LSLDISCUSSION1A normal data distribution is assumed for the population from which the data sample was drawn.DISCUSSION2M values of three or less were used in establishing initial ASTM specification limits; higher values of M result in reduced allowable variabilityfor actua
47、l values when the property of interest is bounded on both sides; in the case of a minimum or maximum, a high value of M can result in theneed for excessively high or low mean property values (x ).mottled iron, na cast iron containing a mixed structure of gray iron and white iron of variable proporti
48、ons. The fracture has amottled appearance.nodular graphite, ngraphite in the form of nodules or spheroids in iron castings.nodularity, nthe volumetric proportion of spheroidal or nodular graphite to total graphite in a ductile iron or a compactedgraphite iron matrix (see Test Method A247, for Evalua
49、ting the Microstructure of Graphite in Iron Castings,2 Types I and II).nodularity, degree of, nthe volumetric proportion of spheroidal or nodular graphite to total graphite in a ductile iron matrix (seeTest Method A247, Types I and II).nodulizing alloy, nan alloy added to molten iron for the primary purpose of causing the formation of spheroidal graphite duringsolidification.pig iron, nthe high carbon iron product obtained by the reduction of iron
