ASTM A1033-2018 Standard Practice for Quantitative Measurement and Reporting of Hypoeutectoid Carbon and Low-Alloy Steel Phase Transformations.pdf

1、Designation: A1033 10 (Reapproved 2015)A1033 18Standard Practice forQuantitative Measurement and Reporting of HypoeutectoidCarbon and Low-Alloy Steel Phase Transformations1This standard is issued under the fixed designation A1033; the number immediately following the designation indicates the year o

2、foriginal adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.1. Scope*1.1 This practice covers the determination of hypoeutectoid s

3、teel phase transformation behavior by using high-speeddilatometry techniques for measuring linear dimensional change as a function of time and temperature, and reporting the resultsas linear strain in either a numerical or graphical format.1.2 The practice is applicable to high-speed dilatometry equ

4、ipment capable of programmable thermal profiles and with digitaldata storage and output capability.1.3 This practice is applicable to the determination of steel phase transformation behavior under both isothermal and continuouscooling conditions.1.4 This practice includes requirements for obtaining

5、metallographic information to be used as a supplement to the dilatometrymeasurements.1.5 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.1.6 This standard does not purport to address all of the safety concerns, if any, associa

6、ted with its use. It is the responsibilityof the user of this standard to establish appropriate safety safety, health, and healthenvironmental practices and determine theapplicability of regulatory limitations prior to use.1.7 This international standard was developed in accordance with internationa

7、lly recognized principles on standardizationestablished in the Decision on Principles for the Development of International Standards, Guides and Recommendations issuedby the World Trade Organization Technical Barriers to Trade (TBT) Committee.2. Referenced Documents2.1 ASTM Standards:2E3 Guide for P

8、reparation of Metallographic SpecimensE112 Test Methods for Determining Average Grain SizeE407 Practice for Microetching Metals and Alloys3. Terminology3.1 Definitions of Terms Specific to This Standard:3.1.1 diametrical linear engineering strainthe strain, either thermal or resulting from phase tra

9、nsformation, that is determinedfrom a change in diameter as a result of a change in temperature, or over a period of time, and which is expressed as follows:eD 5d/d05d12d0!/d03.1.2 hypoeutectoid steela term used to describe a group of carbon steels with a carbon content less than the eutectoidcompos

10、ition (0.8 % by weight).3.1.3 longitudinal linear engineering strainthe strain, either thermal or resulting from phase transformation, that is determinedfrom a change in length as a result of a change in temperature, or over a period of time, and which is expressed as follows:eL 5l/L05l12l0!/l01 Thi

11、s practice is under the jurisdiction of ASTM Committee A01 on Steel, Stainless Steel and Related Alloys and is the direct responsibility of Subcommittee A01.13on Mechanical and Chemical Testing and Processing Methods of Steel Products and Processes.Current edition approved March 1, 2015May 1, 2018.

12、Published March 2015May 2018. Originally approved in 2004. Last previous edition approved in 20102015 asA1033 10.A1033 10 (2015). DOI: 10.1520/A1033-10R15.10.1520/A1033-18.2 For referencedASTM standards, visit theASTM website, www.astm.org, or contactASTM Customer Service at serviceastm.org. For Ann

13、ual Book of ASTM Standardsvolume information, refer to the standards Document Summary page on the ASTM website.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

14、 technically possible to adequately depict all changes accurately, ASTM recommends 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.*A Summary of Changes section appears at the end of

15、 this standardCopyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States13.1.4 steel phase transformationduring heating, the crystallographic transformation from ferrite, pearlite, bainite, martensiteor combinations of these constituents to aust

16、enite. During cooling, the crystallographic transformation from austenite to ferrite,pearlite, bainite, or martensite or a combination thereof.3.1.5 volumetric engineering strainthe strain, either thermal or resulting from phase transformation, that is determined froma change in volume as a result o

17、f a change in temperature, or over a period of time, and which is expressed as follows:eV 5v/v05v12v0!/v0eV3eL3eD3.2 Symbols: eL = longitudinal linear engineering straineD = diametrical linear engineering straineV = volumetric engineering strainl = change in test specimen lengthl1 = test specimen le

18、ngth at specific temperature or time, or bothl0 = initial test specimen lengthd = change in test specimen diameterd1 = test specimen diameter at specific temperature or time, or bothd0 = initial test specimen diameterv = change in test specimen volumev1 = test specimen volume at a specific temperatu

19、re or time, or bothv0 = initial test specimen volumeAc1 = the temperature at which austenite begins to form on heatingAc3 = the temperature at which the transformation of ferrite to austenite is complete on heatingMs = the temperature at which the transformation of austenite to martensite starts dur

20、ing cooling4. Summary of Practice4.1 This practice is based upon the principle that, during heating and cooling of steels, dimensional changes occur as a resultof both thermal expansion associated with temperature change and phase transformation. In this practice, sensitive high-speeddilatometer equ

21、ipment is used to detect and measure the changes in dimension that occur as functions of both time and temperatureduring defined thermal cycles. The resulting data are converted to discrete values of strain for specific values of time andtemperature during the thermal cycle. Strain as a function of

22、time or temperature, or both, can then be used to determine thebeginning and completion of one or more phase transformations.5. Significance and Use5.1 This practice is used to provide steel phase transformation data required for use in numerical models for the prediction ofmicrostructures, properti

23、es, and distortion during steel manufacturing, forging, casting, heat treatment, and welding.Alternatively,the practice provides end users of steel and fabricated steel products the phase transformation data required for selecting steelgrades for a given application by determining the microstructure

24、 resulting from a prescribed thermal cycle.5.1.1 There are available several computer models designed to predict the microstructures, mechanical properties, and distortionof steels as a function of thermal processing cycle. Their use is predicated on the availability of accurate and consistent therm

25、aland transformation strain data. Strain, both thermal and transformation, developed during thermal cycling is the parameter usedin predicting both microstructure and properties, and for estimating distortion. It should be noted that these models are undergoingcontinued development. This process is

26、aimed, among other things, at establishing a direct link between discrete values of strainand specific microstructure constituents in steels. This practice describes a standardized method for measuring strain during adefined thermal cycle.5.1.2 This practice is suitable for providing data for comput

27、er models used in the control of steel manufacturing, forging,casting, heat-treating, and welding processes. It is also useful in providing data for the prediction of microstructures and propertiesto assist in steel alloy selection for end-use applications.5.1.3 This practice is suitable for providi

28、ng the data needed for the construction of transformation diagrams that depict themicrostructures developed during the thermal processing of steels as functions of time and temperature. Such diagrams providea qualitative assessment of the effects of changes in thermal cycle on steel microstructure.

29、Appendix X2 describes construction ofthese diagrams.5.2 It should be recognized that thermal and transformation strains, which develop in steels during thermal cycling, are sensitiveto chemical composition. Thus, anisotropy in chemical composition can result in variability in strain, and can affect

30、the results ofstrain determinations, especially determination of volumetric strain. Strains determined during cooling are sensitive to the grainsize of austenite, which is determined by the heating cycle. The most consistent results are obtained when austenite grain size ismaintained between ASTM gr

31、ain sizes of 5 to 8. Finally, the eutectoid carbon content is defined as 0.8 % for carbon steels.Additions of alloying elements can change this value, along with Ac1 and Ac3 temperatures. Heating cycles need to be employed,as described below, to ensure complete formation of austenite preceding strai

32、n measurements during cooling.A1033 1826. Ordering Information6.1 When this practice is to be applied to an inquiry, contract, or order, the purchaser shall so state and should furnish thefollowing information:6.1.1 The steel grades to be evaluated,6.1.2 The test apparatus to be used,6.1.3 The speci

33、men configuration and dimensions to be used,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 commercially available high-speed dilatometer apparatus, which have certaincommon features. These include t

34、he capabilities for: heating and cooling a steel specimen in vacuum or other controlledatmosphere; programmable thermal cycles; inert gas or liquid injection for rapid cooling; continuous measurement of specimendimension and temperature; and digital data storage and output. The apparatus differ in t

35、erms of method of specimen heating andtest specimen design.7.1.1 Dilatometer Apparatus Using Induction HeatingThe test specimen is heated by suspending it inside an induction-heating coil between two platens as shown schematically in Fig. 1. Cooling is accomplished by a combination of controlledredu

36、ction in heating current along with injection of inert gas onto the test specimen. Dimensional change is measured by amechanical apparatus along the longitudinal axis of the test specimen, and temperature is measured by a thermocouple welded tothe surface of the specimen at the center of the specime

37、n length. For this apparatus, only Type R or S thermocouples should beused.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 contr

38、olled reductionin heating current along with injection of inert gas onto the test specimen or internal liquid quenching. Dimensional change ismeasured along a diameter at the center of the test specimen length, and temperature is measured by a thermocouple welded tothe surface of the specimen at the

39、 center of the specimen length. Dimensional change can be measured by either mechanical ornon-contact (laser) dimension measuring apparatus. Temperature measurement can be made using Type K, Type R, or Type Sthermocouples.8. Test Specimens and Sampling of Test Specimens8.1 Test SpecimensThe test spe

40、cimens to be used with each type of test equipment shall be selected from those shown in Figs.3-5.8.1.1 Dilatometers Apparatus Using Induction HeatingThe specimens to be used with this type of apparatus are shown in Fig.3. The solid specimens may be used for all thermal cycling conditions. The hollo

41、w specimens may also be used for all thermalcycling conditions. The hollow specimens will achieve the highest cooling rates when gas quenching is employed.3 The sole source of supply of the apparatus known to the committee at this time is Dynamic Systems Incorporated, Postenkill, NY. If you are awar

42、e of alternative suppliers,please provide this information toASTM International Headquarters. Your comments will receive careful consideration at a meeting of the responsible technical committee1,which you may attend.FIG. 1 Schematic of Transformation Testing Using Induction HeatingA1033 1838.1.2 Di

43、latometer Apparatus Using Resistance Heating3The specimens for use with this type of apparatus are shown in Figs.4 and 5. The specimen with the reduced center section (Fig. 4) allows for internal cooling of the specimen ends by either liquidor gas. The solid specimen shown in Fig. 5 may be used for

44、all thermal cycling conditions. The hollow specimen shown in Fig.5 may also be used for all thermal cycling conditions.The hollow specimens will achieve the highest cooling rates when quenchingis employed.8.2 SamplingTest specimens may be obtained from any steel product form, including steel bar, pl

45、ate, and sheet and stripproducts. Care should be exercised to avoid the effects of metallurgical variables, such as chemical segregation, in determiningwhere test specimens are obtained from a product form. Procedures have been designed that offer the advantage of equivalencyof strain determination

46、using specimens from both types of apparatus described in 7.1.1 and 7.1.2. For equivalency of strain, theorientation of the longitudinal axis of test specimens for induction heating apparatus should be at 90 degrees to the longitudinalaxis of specimens for resistance heating.8.2.1 Example Sampling f

47、or Steel Bar Product FormsWhere material thickness permits, a selected test specimen should bemachined from the mid-radius position. Where material thickness is insufficient to permit machining a selected test specimen fromFIG. 2 Schematic of Transformation Testing Using Resistance HeatingNOTE 1All

48、machining surface finishes being 0.8 m RMSFIG. 3 Test Specimens for Induction Heating ApparatusA1033 184NOTE 1All machining surface finishes being 0.8 m RMSTest Specimen Dimension Guide TableSpecimen Length,L1 0.10 (mm)Specimen Half Length,L2 0.05 (mm)Reduced SectionLength,L3 0.025 (mm)Reduced Secti

49、on Diameter,D3 0.025 (mm)OD at Grip End,D1 0.025 (mm)ID at Grip End,D2 0.025 (mm)Grip End Drill Depth,L4 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 Specimens with Reduced Center Section for Resistance Heating ApparatusNOTE 1All machining surface finishes being 0.8 m RMS.Test Specimen Dimension Guide TableSpecimen Length,L1 0.10 (mm)Specimen Half Length,L2 0.05 (mm)Reduced SectionLength,L3 0.025 (mm)Reduced Section Diameter,D3 0.025 (mm)OD at Grip End,D1 0.025 (mm)ID at Grip End,D2 0.025