1、Designation: A 1033 04Standard Practice forQuantitative Measurement and Reporting of HypoeutectoidCarbon and Low-Alloy Steel Phase Transformations1This standard is issued under the fixed designation A 1033; the number immediately following the designation indicates the year oforiginal adoption or, i
2、n the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon (e) indicates an editorial change since the last revision or reapproval.1. Scope1.1 This practice covers the determination of hypoeutectoidsteel phase transformation
3、 behavior by using high-speeddilatometry techniques for measuring linear dimensionalchange as a function of time and temperature, and reporting theresults as linear strain in either a numerical or graphical format.1.2 The practice is applicable to high-speed dilatometryequipment capable of programma
4、ble thermal profiles and withdigital data storage and output capability.1.3 This practice is applicable to the determination of steelphase transformation behavior under both isothermal andcontinuous cooling conditions.1.4 This practice includes requirements for obtaining met-allographic information
5、to be used as a supplement to thedilatometry measurements.1.5 This standard does not purport to address all of thesafety concerns, if any, associated with its use. It is theresponsibility of the user of this standard to establish appro-priate safety and health practices and determine the applica-bil
6、ity of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:2E 3 Practice for Preparation of Metallographic SpecimensE 112 Test Methods for Determining Average Grain SizeE 407 Practice for Microetching Metals and Alloys3. Terminology3.1 Definitions of Terms Specific to This
7、Standard:3.1.1 diametrical linear engineering strainthe strain, ei-ther thermal or resulting from phase transformation, that isdetermined from a change in diameter as a result of a changein temperature, or over a period of time, and which is expressedas follows:eD5Dd/d05 d12 d0!/d03.1.2 hypoeutectoi
8、d steela term used to describe a groupof carbon steels with a carbon content less than the eutectoidcomposition (0.8 % by weight).3.1.3 longitudinal linear engineering strainthe strain, ei-ther thermal or resulting from phase transformation, that isdetermined from a change in length as a result of a
9、 change intemperature, or over a period of time, and which is expressedas follows:eL5Dl/L05 l12 l0!/l03.1.4 steel phase transformationduring heating, the crys-tallographic transformation from ferrite, pearlite, bainite, mar-tensite or combinations of these constituents to austenite.During cooling, t
10、he crystallographic transformation from aus-tenite to ferrite, pearlite, bainite, or martensite or a combinationthereof.3.1.5 volumetric engineering strainthe strain, either ther-mal or resulting from phase transformation, that is determinedfrom a change in volume as a result of a change in temperat
11、ure,or over a period of time, and which is expressed as follows:eV5Dv/v05 v12 v0!/v0eV 3eL 3eD3.2 Symbols:eL= longitudinal linear engineering straineD= diametrical linear engineering straineV= volumetric engineering strainDl = change in test specimen lengthl1= test specimen length at specific temper
12、ature or time, orbothl0= initial test specimen lengthDd = change in test specimen diameterd1= test specimen diameter at specific temperature or time,or bothd0= initial test specimen diameterDv = change in test specimen volumev1= test specimen volume at a specific temperature or time,or bothv0= initi
13、al test specimen volumeAc1= the temperature at which austenite begins to form onheating1This practice is under the jurisdiction of ASTM Committee A01 on Steel,Stainless Steel and Related Alloys and is the direct responsibility of SubcommitteeA01.13 on Mechanical and Chemical Testing and Processing M
14、ethods of SteelProducts and Processes.Current edition approved March 1, 2004. Published March 2004.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Doc
15、ument Summary page onthe ASTM website.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.Ac3= the temperature at which the transformation of ferriteto austenite is complete on heatingMs= the temperature at which the transformation of au
16、ste-nite to martensite starts during cooling4. Summary of Practice4.1 This practice is based upon the principle that, duringheating and cooling of steels, dimensional changes occur as aresult of both thermal expansion associated with temperaturechange and phase transformation. In this practice, sens
17、itivehigh-speed dilatometer equipment is used to detect and mea-sure the changes in dimension that occur as functions of bothtime and temperature during defined thermal cycles. Theresulting data are converted to discrete values of strain forspecific values of time and temperature during the thermalc
18、ycle. Strain as a function of time or temperature, or both, canthen be used to determine the beginning and completion of oneor more phase transformations.5. Significance and Use5.1 This practice is used to provide steel phase transforma-tion data required for use in numerical models for the predic-t
19、ion of microstructures, properties, and distortion during steelmanufacturing, forging, casting, heat treatment, and welding.Alternatively, the practice provides end users of steel andfabricated steel products the phase transformation data requiredfor selecting steel grades for a given application by
20、 determin-ing the microstructure resulting from a prescribed thermalcycle.5.1.1 There are available several computer models designedto predict the microstructures, mechanical properties, anddistortion of steels as a function of thermal processing cycle.Their use is predicated on the availability of
21、accurate andconsistent thermal and transformation strain data. Strain, boththermal and transformation, developed during thermal cyclingis the parameter used in predicting both microstructure andproperties, and for estimating distortion. It should be noted thatthese models are undergoing continued de
22、velopment. Thisprocess is aimed, among other things, at establishing a directlink between discrete values of strain and specific microstruc-ture constituents in steels. This practice describes a standard-ized method for measuring strain during a defined thermalcycle.5.1.2 This practice is suitable f
23、or providing data for com-puter models used in the control of steel manufacturing,forging, casting, heat-treating, and welding processes. It is alsouseful in providing data for the prediction of microstructuresand properties to assist in steel alloy selection for end-useapplications.5.1.3 This pract
24、ice is suitable for providing the data neededfor the construction of transformation diagrams that depict themicrostructures developed during the thermal processing ofsteels as functions of time and temperature. Such diagramsprovide a qualitative assessment of the effects of changes inthermal cycle o
25、n steel microstructure. Appendix X2 describesconstruction of these diagrams.5.2 It should be recognized that thermal and transformationstrains, which develop in steels during thermal cycling, aresensitive to chemical composition. Thus, anisotropy in chemi-cal composition can result in variability in
26、 strain, and can affectthe results of strain determinations, especially determination ofvolumetric strain. Strains determined during cooling are sen-sitive to the grain size of austenite, which is determined by theheating cycle. The most consistent results are obtained whenaustenite grain size is ma
27、intained between ASTM grain sizes of5 to 8. Finally, the eutectoid carbon content is defined as 0.8 %for carbon steels. Additions of alloying elements can changethis value, along with Ac1and Ac3temperatures. Heatingcycles need to be employed, as described below, to ensurecomplete formation of austen
28、ite preceding strain measurementsduring cooling.6. Ordering Information6.1 When this practice is to be applied to an inquiry,contract, or order, the purchaser shall so state and shouldfurnish the following information:6.1.1 The steel grades to be evaluated,6.1.2 The test apparatus to be used,6.1.3 T
29、he specimen configuration and dimensions to beused,6.1.4 The thermal cycles to be used, and6.1.5 The supplementary requirements desired.7. Apparatus7.1 This practice is applicable to several types of commer-cially available high-speed dilatometer apparatus, which havecertain common features. These i
30、nclude the capabilities for:heating and cooling a steel specimen in vacuum or othercontrolled atmosphere; programmable thermal cycles; inert gasor liquid injection for rapid cooling; continuous measurementof specimen dimension and temperature; and digital datastorage and output. The apparatus differ
31、 in terms of method ofspecimen heating and test specimen design.7.1.1 Dilatometer Apparatus Using Induction HeatingThe test specimen is heated by suspending it inside aninduction-heating coil between two platens as shown schemati-cally in Fig. 1. Cooling is accomplished by a combination ofcontrolled
32、 reduction in heating current along with injection ofinert gas onto the test specimen. Dimensional change ismeasured by a mechanical apparatus along the longitudinalaxis of the test specimen, and temperature is measured by athermocouple welded to the surface of the specimen at thecenter of the speci
33、men length. For this apparatus, only Type Ror S thermocouples should be used.7.1.2 Dilatometer Apparatus Using Resistance Heating3The test specimen is supported between two grips as shownschematically in Fig. 2, and heated by direct resistance heating.Cooling is accomplished by a combination of cont
34、rolledreduction in heating current along with injection of inert gasonto the test specimen or internal liquid quenching. Dimen-sional change is measured along a diameter at the center of thetest specimen length, and temperature is measured by a3The sole source of supply of the apparatus known to the
35、 committee at this timeis Dynamic Systems Incorporated, Postenkill, NY. If you are aware of alternativesuppliers, please provide this information to ASTM International Headquarters.Your comments will receive careful consideration at a meeting of the responsibletechnical committee1, which you may att
36、end.A1033042thermocouple welded to the surface of the specimen at thecenter of the specimen length. Dimensional change can bemeasured by either mechanical or non-contact (laser) dimen-sion measuring apparatus. Temperature measurement can bemade using Type K, Type R, or Type S thermocouples.8. Test S
37、pecimens and Sampling of Test Specimens8.1 Test SpecimensThe test specimens to be used witheach type of test equipment shall be selected from those shownin Figs. 3-5.8.1.1 Dilatometers Apparatus Using Induction HeatingThe specimens to be used with this type of apparatus are shownin Fig. 3. The solid
38、 specimens may be used for all thermalcycling conditions. The hollow specimens may also be used forall thermal cycling conditions. The hollow specimens willachieve the highest cooling rates when gas quenching isemployed.8.1.2 Dilatometer Apparatus Using Resistance Heating3The specimens for use with
39、this type of apparatus are shown inFigs. 4 and 5. The specimen with the reduced center section(Fig. 4) allows for internal cooling of the specimen ends byeither liquid or gas. The solid specimen shown in Fig. 5 may beused for all thermal cycling conditions. The hollow specimenshown in Fig. 5 may als
40、o be used for all thermal cyclingconditions. The hollow specimens will achieve the highestcooling rates when quenching is employed.8.2 SamplingTest specimens may be obtained from anysteel product form, including steel bar, plate, and sheet andstrip products. Care should be exercised to avoid the eff
41、ects ofmetallurgical variables, such as chemical segregation, in deter-mining where test specimens are obtained from a product form.Procedures have been designed that offer the advantage ofequivalency of strain determination using specimens from bothtypes of apparatus described in 7.1.1 and 7.1.2. F
42、or equiva-lency of strain, the orientation of the longitudinal axis of testspecimens for induction heating apparatus should be at 90degrees to the longitudinal axis of specimens for resistanceheating.8.2.1 Example Sampling for Steel Bar Product FormsWhere material thickness permits, a selected test
43、specimenshould be machined from the mid-radius position. Wherematerial thickness is insufficient to permit machining a selectedtest specimen from the mid-radius position but sufficient topermit machining the test specimen from the mid-diameterFIG. 1 Schematic of Transformation Testing Using Inductio
44、n HeatingFIG. 2 Schematic of Transformation Testing Using Resistance HeatingA1033043position, the test specimen may be obtained from the mid-diameter position. In all cases, material thickness must besufficient to permit machining a fully dimensioned test speci-men.8.2.1.1 Dilatometer Apparatus Usin
45、g Induction HeatingThe test specimens are to be machined with the longitudinalaxis of the test specimen perpendicular to the rolling directionof the bar. Fig. 6 shows example orientations.8.2.1.2 Dilatometer Apparatus Using Resistance HeatingThe test specimens are to be machined with the longitudina
46、laxis of the test specimen parallel to the rolling direction of thebar. Fig. 6 shows example orientations.NOTEAll machining surface finishes being 0.8 m RMSFIG. 3 Test Specimens for Induction Heating ApparatusNOTEAll machining surface finishes being 0.8 m RMSTest Specimen Dimension Guide TableSpecim
47、en Length,L1 6 0.10 (mm)Specimen Half Length,L2 6 0.05 (mm)Reduced Section Length,L3 6 0.025 (mm)Reduced Section Diameter,D3 6 0.025 (mm)OD at Grip End,D1 6 0.025 (mm)ID at Grip End,D2 6 0.025 (mm)Grip End Drill Depth,L4 6 0.05 (mm)90 45 6 6 10 6.3 4084 42 6 6 10 6.3 3784 42 5 5 10 6.3 37FIG. 4 Test
48、 Specimens with Reduced Center Section for Resistance Heating ApparatusA1033044NOTEAll machining surface finishes being 0.8 m RMS.Test Specimen Dimension Guide TableSpecimen Length,L1 6 0.10 (mm)Specimen Half Length,L2 6 0.05 (mm)Reduced Section Length,L3 6 0.025 (mm)Reduced Section Diameter,D3 6 0.
49、025 (mm)OD at Grip End,D1 6 0.025 (mm)ID at Grip End,D2 6 0.025 (mm)Grip End Drill Depth,L4 6 0.05 (mm)90 45 6 6 10 6.3 4084 42 6 6 10 6.3 3784 42 5 5 10 6.3 37FIG. 5 Test Specimens for Resistance Heating ApparatusFIG. 6 Machining Orientations for Bar Steel Product FormsA10330459. Calibration9.1 Apparatus and ComponentsIndividually calibrate thetemperature, time (sampling rate), and length change signalsaccording to appropriate manufacturers recommendations.9.2 Use of Standard Reference MaterialTo ensure accu-rate test results, a calibration procedure must
