ASTM E436-2003(2014) 9782 Standard Test Method for Drop-Weight Tear Tests of Ferritic Steels《铁素体钢的坠重破裂试验的标准试验方法》.pdf

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1、Designation: E436 03 (Reapproved 2014)Standard Test Method forDrop-Weight Tear Tests of Ferritic Steels1This standard is issued under the fixed designation E436; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revi

2、sion. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.1. Scope1.1 This test method covers drop-weight tear tests (DWTT)on ferritic steels with thicknesses between 3.18 and 19.1 mm.1.2 The value

3、s stated in SI units are to be regarded asstandard. No other units of measurement are included in thisstandard.1.3 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 safe

4、ty and health practices and determine the applica-bility of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:2E208 Test Method for Conducting Drop-Weight Test toDetermine Nil-Ductility Transition Temperature of Fer-ritic SteelsE1823 Terminology Relating to Fatigue and Fr

5、acture Testing3. Terminology3.1 Terminology E1823 is applicable to this test method.4. Significance and Use4.1 This test method can be used to determine the appear-ance of propagating fractures in plain carbon or low-alloy pipesteels (yield strengths less than 825 MPa) over the temperaturerange wher

6、e the fracture mode changes from brittle (cleavageor flat) to ductile (shear or oblique).4.2 This test method can serve the following purposes:4.2.1 For research and development, to study the effect ofmetallurgical variables such as composition or heat treatment,or of fabricating operations such as

7、welding or forming on themode of fracture propagation.4.2.2 For evaluation of materials for service to indicate thesuitability of a material for specific applications by indicatingfracture propagation behavior at the service temperature(s).4.2.3 For information or specification purposes, to provide

8、amanufacturing quality control only when suitable correlationshave been established with service behavior.5. Apparatus5.1 The testing machine shall be either a pendulum type ora vertical-dropped-weight (Note 1) type. The machine shallprovide sufficient energy to completely fracture a specimen inone

9、impact.5.1.1 As a guide in the design of the equipment it has beenfound that up to 2712 J of energy may be required tocompletely fracture specimens of steel up to 12.7 mm inthickness with tensile strengths to 690 MPa.NOTE 1Equipment of the vertical-dropped-weight variety that can bereadily modified

10、to conduct the drop-weight tear test is described in TestMethod E208.NOTE 2Current pipeline grade steels take more thn 4kJ at designtemperature of -5C5.2 The specimen shall be supported in a suitable manner toprevent sidewise rotation of the specimen.5.3 The velocity of the hammer (in either type of

11、 testingmachine) shall be not less than 4.88 m/s.6. Test Specimen6.1 The test specimen shall be a 76.2 by 305-mm byfull-plate-thickness edge-notch bend specimen employing apressed notch. Fig. 1 presents the dimensions and tolerances ofthe specimens. The specimens shall be removed from thematerial un

12、der test by sawing, shearing, or flame cutting, withor without machining.NOTE 3If the specimen is flame cut it is usually difficult to press in thenotch unless the heat-affected zone is removed by machining.6.2 The notch shall be pressed to the depth shown in Fig. 1with a sharp tool-steel chisel wit

13、h an included angle of 45 62. Machined notches are prohibited.NOTE 4The notch radius obtained with a sharp tool-steel chisel isnormally between 0.013 to 0.025 mm. When many specimens are to betested, it is helpful to use a jig that will guide the chisel and stop it at theproper depth.1This method is

14、 under the jurisdiction of ASTM Committee E08 on Fatigue andFractureand is the direct responsibility of Subcommittee E08.02 on Standards andTerminology.Current edition approved July 1, 2014. Published September 2014. Originallyapproved in 1971. Last previous edition approved 2008 as E43603(2008). DO

15、I:10.1520/E0436-03R14.2For 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 Document Summary page onthe ASTM website.Copyright ASTM International, 100 Barr

16、Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States17. Procedure7.1 In the temperature range from 73 to 100C employ theprocedure described in 7.1.1 and 7.1.2.7.1.1 Completely immerse the specimens in a bath ofsuitable liquid at a temperature within 61C of the desired testtempe

17、rature for a minimum time of 15 min prior to testing.Separate the specimens by a distance at least equal to thethickness of the specimen. Make provision for circulation ofthe bath to assure uniform bath temperature.NOTE 5Alternatively, other methods of heating and cooling may beused, provided they p

18、roduce equivalent time at temperature of thespecimens.7.1.2 Remove the specimens from the bath and break asdescribed herein within a time period of 10-s. If the specimensare held out of the bath longer than 10 s return them unbrokento the bath for a minimum of 10 min. Do not handle thespecimen in th

19、e vicinity of the notch by devices the tempera-ture of which is appreciably different from the test temperature.7.2 For temperatures outside of the range specified in 7.1maintain the specimen temperature at the time of impact within4C of the desired test temperature.7.3 Insert the specimen in the te

20、sting machine so that thenotch in the specimen lines up with the centerline of the tup onthe hammer within 1.59 mm. Also, center the notch in thespecimen between the supports on the anvil.7.4 Consider tests invalid if the specimen buckles duringimpact.NOTE 6Buckling has been experienced with specime

21、n thicknessesless than 4.75 mm.8. Specimen Evaluation8.1 For the purposes of this method, shear-fracture surfacesshall be considered as those having a dull gray silky appear-ance which are commonly inclined at an angle to the specimensurface. Cleavage or brittle fractures shall be considered thoseth

22、at are bright and crystalline in appearance and that areperpendicular to the plate surface. The cleavage fracturesgenerally extend from the root of the notch and are surroundedby a region of shear or shear lips on the specimen surface.8.2 Evaluate the specimens (Note 7) by determining thepercent she

23、ar area of the fracture surface neglecting thefracture surface for a distance of one specimen thickness fromthe root of the notch and the fracture surface for a distance ofone specimen thickness from the edge struck by the hammer.Fig. 2 illustrates in the cross-hatched area that portion of thefractu

24、re surface to be considered in the evaluation of thepercent shear area of the fracture surface.NOTE 7If the specimens are to be preserved for some length of timeafter evaluation of the shear area or if a considerable time elapses betweentesting and evaluation, the fracture surfaces should be treated

25、 to keep themfrom corroding.8.3 Occasionally specimens will exhibit the fracture appear-ance shown in Fig. 3. On specimens of this type the fractureappears to have stopped and started a number of timesexhibiting intermittent regions of shear and cleavage in themidthickness portion of the specimen. T

26、he shear area includedin the rating of specimens of this type shall be that shown in thecross-hatched area of Fig. 3 (neglect the shear areas in theregion of intermittent shear and cleavage fracture in rating thespecimen).8.4 For referee method of determining the percent sheararea of the fracture su

27、rface, measure the cleavage area of thefracture surface with a planimeter on a photograph or opticalprojection of the fracture surface. Then divide the cleavagearea by the net area of the specimen included in the rating,express as percent, and subtract from 100.Alternative methodsmore adaptable to r

28、outine rating are described in 8.4.1 8.4.3.8.4.1 The percent shear area can be evaluated by comparingthe fracture surfaces with a calibrated set of photographs ofpreviously fractured specimens or with actual specimens ofFIG. 1 Drop-Weight Tear Test Specimens and Support Dimensions and Tolerances (fo

29、r Specimens18 to34 in. in Thickness)FIG. 2 Fracture Surface Included in Shear-Area DeterminationFIG. 3 Alternative Shear-Cleavage Fracture AppearanceE436 03 (2014)2calibrated percent shear areas for a specific thickness. Calibratein accordance with 8.4.8.4.2 The percent shear area can be evaluated w

30、ith theprocedure described in Annex A1.8.4.3 The percent shear area can be evaluated with any otherprocedure that has been demonstrated to produce resultsequivalent to those obtained in 8.4.8.5 Fig. 4 shows five DWTT specimens that have beentested over the temperature range from 17 to 16C . Thebrigh

31、t regions of the fracture are the cleavage fracture areasand the darker gray regions are the areas of shear fracture.(Note that the specimen tested at 4C has almost 100 % sheararea and it has a fracture surface that in section has shear lipson each surface with a region of flat fibrous shear at them

32、idthickness (see Section AA of Fig. A1.1(a). This fractureappearance is typical of a full shear fracture and is easilydistinguished from the flat cleavage fracture in the center of thespecimen with shear lips at the specimen surfaces.9. Report9.1 A report of the test results shall be furnished to th

33、epurchaser and shall include as a minimum the specimenorientation in product (transverse or longitudinal), thickness,heat number, material specification, test temperature, and thefracture appearance (percent shear area) of each specimen. If aseries of specimens is broken over a range of temperatures

34、, aplot of the results as percent shear area versus temperature isdesirable.10. Precision and Bias10.1 PrecisionIt is not practicable to specify the precisionof the procedure in Test Method E436 for measuring thefracture appearance (percent shear area) as the available dataare not of a type that per

35、mits a meaningful analysis.10.2 BiasThere is no accepted “standard” value for thepercent shear area of any material. In the absence of such a truevalue, no meaningful statement can be made concerning bias ofdata.11. Keywords11.1 brittle fracture; drop-weight tear test; ferritic steels;fracture appea

36、rance; impact loading; percent shear areaFIG. 4 DWTT Fracture AppearancesE436 03 (2014)3ANNEXES(Mandatory Information)A1. PROCEDURE FOR MEASUREMENT OF DWTT PERCENT SHEAR AREAA1.1 Many ways have been suggested and tried for mea-suring the percent shear of DWTT specimens. Some of themethods such as ph

37、otographing and planimetering the fractureare accurate but slow; other methods such as measuring theshear at the midpoint of the specimen are rapid but not accurateenough. The procedure outlined herein has been developedover a period of time as a reasonably accurate and rapidmethod of measuring the

38、percent shear area.A1.2 It has been found that the procedure to be useddepends upon the configuration of the fracture surface. Fig.A1.1 shows three representative fracture surfaces. On speci-mens exhibiting fracture surfaces between Fig. A1.1(a) andFig.A1.1(b) the shear area is calculated assuming t

39、he cleavageportion of the fracture is a third-degree curvethis approxi-mates the cleavage fracture surface configuration with reason-able accuracy.3The procedure for this specimen appearance isto measure the length of the cleavage fracture in between thetwo “t” lines (B dimensions in Fig.A1.2 and Fi

40、g.A1.3) and thewidth of the cleavage fracture at the one “t” line beneath thenotch. From these dimensions the area of the cleavage portionof the fracture surface can be calculated as34 AB. Subtractingthis from the net area of the fracture surface and dividing theresult by the net area of the fractur

41、e surface results in thepercent shear area when multipled by 100. This procedureresults in the following equation which is applicable betweenapproximately 45 and 100 % shear or to the point where thecleavage fracture extends to the one “t” line on the back end ofthe specimen.%SA52.8 2 2t!t 234AB2.8

42、2 2t!t3100 (A1.1)where:%SA = percent shear area,A = the width of the cleavage fracture at the one “t” linebeneath the notch, in., andB = the length of the cleavage fracture in between thetwo “t” lines, in.A1.3 Rather than make the calculation for each specimen itis quicker to compute the data for va

43、rious thicknesses. Fig.A1.2 and Fig. A1.3 are examples of plots for determiningpercent shear of 0.312 and 0.344-in. -thick material. Withfigures such as these it is possible to determine shear areas ofspecimens by measuring the A and B dimensions of the fracturesurfaces for shear areas in the range

44、from 45 to 100 %.A1.4 In the shear range between 0 and 45 %, represented bythe fracture surface shown in Fig.A1.1(c), to obtain the percentshear make three measurements of the total shear lip thick-nesses (include both shear lips) between the one “t” lines asshown in Fig. A1.1(c), average them and d

45、ivide by thespecimen thickness. Convert the results to percent by multi-plying by 100. The shear-lip thicknesses versus percent shearfor a specific plate thickness may be tabulated for ease ofdetermination.3Symposium on Line Pipe Research, L30000, American Gas Assn., New York,NY, 1965, pp. 83118.FIG

46、. A1.1 Representative DWTT Fracture SurfacesE436 03 (2014)4A2. INTERPRETATION OF DROP-WEIGHT TEAR TEST RESULTSA2.1 Considerable research has been conducted on thesignificance of the drop-weight tear test (DWTT) results.Included in this test method is a list of selected references. Theresearch has in

47、volved numerous tests on large-diameter steelpipe in which fractures were purposely initiated.4Correlatingthe results of full-scale pipe tests with the results of the DWTTindicated that the transition in full-scale fracture propagationappearance (fracture appearance remote from the initiationregion)

48、 occurred at the same temperature as the transition in theDWTT percent shear area. Thus the DWTT defined a fracture-propagation transition temperature (FPTT).4Brubaker, E. H., and Dennison, J. D., “Use of the Battelle Drop Weight TearTest for Determining Notch Toughness of Line Pipe Steel,” Journal

49、of Metals, Am.Inst. of Mining and Metallurgical Engrs.,Vol 17, No.9, September, 1965, pp.985992.FIG. A1.2 Chart for Determining Percent Shear for 0.312-in. MaterialFIG. A1.3 Chart for Determining Percent Shear for 0.344-in. MaterialE436 03 (2014)5A2.2 The work performed by the Committee E24 Subcom-mittee III task group5has shown that for specimen thicknessesless than 19.05 mm the determination of transition temperatureat a specific shear area level is reproducible to 6 -12C.Furthermore, the results of the task group have shown that thestandard d