1、Designation: E 436 03Standard Test Method forDrop-Weight Tear Tests of Ferritic Steels1This standard is issued under the fixed designation E 436; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revision. A number i
2、n parentheses indicates the year of last reapproval. Asuperscript epsilon (e) 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(0.125 and 0.750 in.).1.2 The
3、 values stated in SI (metric) units are to be regardedas the standard.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 safety and health practices and determine the
4、 applica-bility of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:E 208 Test Method for Conducting Drop-Weight Test toDetermine Nil-Ductility Transition Temperature of FerriticSteels2E 1823 Terminology Relating to Fatigue and Fracture Test-ing23. Significance and Use3.
5、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 or 120 000 psi) overthe temperature range where the fracture mode changes frombrittle (cleavage or flat) to ductile (shear or oblique).3.2 T
6、his test method can serve the following purposes:3.2.1 For research and development, to study the effect ofmetallurgical variables such as composition or heat treatment,or of fabricating operations such as welding or forming on themode of fracture propagation.3.2.2 For evaluation of materials for se
7、rvice to indicate thesuitability of a material for specific applications by indicatingfracture propagation behavior at the service temperature(s).3.2.3 For information or specification purposes, to provide amanufacturing quality control only when suitable correlationshave been established with servi
8、ce behavior.4. Apparatus4.1 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 impact.4.1.1 As a guide in the design of the equipment it has beenfound that up to 2712 J (200
9、0 ftlbf) of energy may be requiredto completely fracture specimens of steel up to 12.7 mm (12in.) in thickness with tensile strengths to 690 MPa (100 000psi).NOTE 1Equipment of the vertical-dropped-weight variety that can bereadily modified to conduct the drop-weight tear test is described in TestMe
10、thod E 208.NOTE 2Current pipeline grade steels take more thn 4kJ at designtemperature of -5C4.2 The specimen shall be supported in a suitable manner toprevent sidewise rotation of the specimen.4.3 The velocity of the hammer (in either type of testingmachine) shall be not less than 4.88 m/s (16 ft/s)
11、.5. Test Specimen5.1 The test specimen shall be a 76.2 by 305-mm (3 by12-in.) by full-plate-thickness edge-notch bend specimen em-ploying a pressed notch. Fig. 1 presents the dimensions andtolerances of the specimens. The specimens shall be removedfrom the material under test by sawing, shearing, or
12、 flamecutting, with or 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.5.2 The notch shall be pressed to the depth shown in Fig. 1with a sharp tool-steel chisel with an included angle of 45 62. Ma
13、chined notches are prohibited.NOTE 4The notch radius obtained with a sharp tool-steel chisel isnormally between 0.013 to 0.025 mm (0.0005 to 0.001 in.). When manyspecimens are to be tested, it is helpful to use a jig that will guide thechisel and stop it at the proper depth.6. Procedure6.1 In the te
14、mperature range from 73 to 100C (100to + 212F) employ the procedure described in 6.1.1 and 6.1.2.1This method is under the jurisdiction of ASTM Committee E08 on Fatigue andFracture and is the direct responsibility of Subcommittee E08.02 on Standards andTerminology.Current edition approved May 10, 20
15、03. Published June 2003. Originallyapproved in 1971. Last previous edition approved 1997 as E 436 91(1997).2Annual Book of ASTM Standards, Vol 03.01.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.6.1.1 Completely immerse the specime
16、ns in a bath ofsuitable liquid at a temperature within 61C (62F) of thedesired test temperature for a minimum time of 15 min prior totesting. Separate the specimens by a distance at least equal tothe thickness of the specimen. Make provision for circulationof the bath to assure uniform bath temperat
17、ure.NOTE 5Alternatively, other methods of heating and cooling may beused, provided they produce equivalent time at temperature of thespecimens.6.1.2 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
18、 return them unbrokento the bath for a minimum of 10 min. Do not handle thespecimen in the vicinity of the notch by devices the tempera-ture of which is appreciably different from the test temperature.6.2 For temperatures outside of the range specified in 6.1maintain the specimen temperature at the
19、time of impact within4C (6 2F) of the desired test temperature.6.3 Insert the specimen in the testing machine so that thenotch in the specimen lines up with the centerline of the tup onthe hammer within 1.59 mm (116 in.). Also, center the notch inthe specimen between the supports on the anvil.6.4 Co
20、nsider tests invalid if the specimen buckles duringimpact.NOTE 6Buckling has been experienced with specimen thicknessesless than 4.75 mm (0.187 in.).7. Specimen Evaluation7.1 For the purposes of this method, shear-fracture surfacesshall be considered as those having a dull gray silky appear-ance whi
21、ch are commonly inclined at an angle to the specimensurface. Cleavage or brittle fractures shall be considered thosethat 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 r
22、egion of shear or shear lips on the specimen surface.7.2 Evaluate the specimens (Note 7) by determining thepercent shear 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 specim
23、en thickness from the edge struck by the hammer.Fig. 2 illustrates in the cross-hatched area that portion of thefracture 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 t
24、he shear area or if a considerable time elapses betweentesting and evaluation, the fracture surfaces should be treated to keep themfrom corroding.7.3 Occasionally specimens will exhibit the fracture appear-ance shown in Fig. 3. On specimens of this type the fractureappears to have stopped and starte
25、d a number of timesexhibiting intermittent regions of shear and cleavage in themidthickness portion of the specimen. The 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 c
26、leavage fracture in rating thespecimen).7.4 For referee method of determining the percent sheararea of the fracture surface, 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 o
27、f the specimen included in the rating,express as percent, and subtract from 100. Alternative methodsmore adaptable to routine rating are described in 7.4.1-7.4.3.7.4.1 The percent shear area can be evaluated by comparingthe fracture surfaces with a calibrated set of photographs ofpreviously fracture
28、d specimens or with actual specimens ofcalibrated percent shear areas for a specific thickness. Calibratein accordance with 7.4.7.4.2 The percent shear area can be evaluated with theprocedure described in Annex A1.FIG. 1 Drop-Weight Tear Test Specimens and Support Dimensions and Tolerances (for Spec
29、imens18 to34 in. in Thickness)FIG. 2 Fracture Surface Included in Shear-Area DeterminationFIG. 3 Alternative Shear-Cleavage Fracture AppearanceE4360327.4.3 The percent shear area can be evaluated with any otherprocedure that has been demonstrated to produce resultsequivalent to those obtained in 7.4
30、.7.5 Fig. 4 shows five DWTT specimens that have beentested over the temperature range from 17 to 16C (0 to60F). The bright regions of the fracture are the cleavagefracture areas and the darker gray regions are the areas of shearfracture. (Note that the specimen tested at 4C (40F) hasalmost 100 % she
31、ar area and it has a fracture surface that insection has shear lips on each surface with a region of flatfibrous shear at the midthickness (see Section AA of Fig.A1.1(a). This fracture appearance is typical of a full shearfracture and is easily distinguished from the flat cleavagefracture in the cen
32、ter of the specimen with shear lips at thespecimen surfaces.8. Report8.1 A report of the test results shall be furnished to thepurchaser and shall include as a minimum the specimenorientation in product (transverse or longitudinal), thickness,heat number, material specification, test temperature, an
33、d thefracture appearance (percent shear area) of each specimen. If aseries of specimens is broken over a range of temperatures, aplot of the results as percent shear area versus temperature isdesirable.9. Precision and Bias9.1 PrecisionIt is not practicable to specify the precisionof the procedure i
34、n Test Method E 436 for measuring thefracture appearance (percent shear area) as the available dataare not of a type that permits a meaningful analysis.9.2 BiasThere is no accepted “standard” value for thepercent shear area of any material. In the absence of such a truevalue, no meaningful statement
35、 can be made concerning bias ofdata.10. Keywords10.1 brittle fracture; drop-weight tear test; ferritic steels;fracture appearance; impact loading; percent shear areaFIG. 4 DWTT Fracture AppearancesE436033ANNEXES(Mandatory Information)A1. PROCEDURE FOR MEASUREMENT OF DWTT PERCENT SHEAR AREAA1.1 Many
36、ways have been suggested and tried formeasuring the percent shear of DWTT specimens. Some of themethods such as photographing 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
37、outlined herein has been developedover a period of time as a reasonably accurate and rapidmethod of measuring the 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 s
38、peci-mens exhibiting fracture surfaces between Fig. A1.1(a) andFig. A1.1(b) the shear area is calculated assuming the 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 appea
39、rance isto measure the length of the cleavage fracture in between thetwo “t” lines (B dimensions in Fig. A1.2 and Fig. 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 as3
40、4 AB. Subtractingthis from the net area of the fracture surface and dividing theresult by the net area of the fracture 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
41、 point where thecleavage fracture extends to the one “t” line on the back end ofthe specimen.(A1.1) %SA 5 2.8 2 2t!t 2 n|PAB2.8 2 2t!t 3 100where:%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 b
42、etween thetwo “t” lines, in.A1.3 Rather than make the calculation for each specimen itis quicker to compute the data for various 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
43、determine shear areas ofspecimens by measuring the A and B dimensions of the fracturesurfaces for shear areas in the range from 45 to 100 %.A1.4 In the shear range between 0 and 45 %, representedby the fracture surface shown in Fig. A1.1(c), to obtain thepercent shear make three measurements of the
44、total shear lipthicknesses (include both shear lips) between the one “t” linesas shown in Fig. A1.1(c), average them and divide 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 tabulat
45、ed for ease ofdetermination.3Symposium on Line Pipe Research, L30000, American Gas Assn., New York,NY, 1965, pp. 83118.FIG. A1.1 Representative DWTT Fracture SurfacesE436034A2. INTERPRETATION OF DROP-WEIGHT TEAR TEST RESULTSA2.1 Considerable research has been conducted on thesignificance of the drop
46、-weight tear test (DWTT) results.Included in this test method is a list of selected references. Theresearch has involved 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
47、the transition in full-scale fracture propagationappearance (fracture appearance remote from the initiationregion) 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 Dennis
48、on, J. D., “Use of the Battelle Drop Weight TearTest for Determining Notch Toughness of Line Pipe Steel,” Journal 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
49、Determining Percent Shear for 0.344-in. MaterialE436035A2.2 The work performed by the Committee E24 Subcom-mittee III task group5has shown that for specimen thicknessesless than 19.05 mm (0.750 in.) the determination of transitiontemperature at a specific shear area level is reproducible to 6-12C (6 10F). Furthermore, the results of the task grouphave shown that the standard deviations for the determinationof percent shear area are as shown in the following table:Shear area, % Standard Deviation, % SA030 63185 1086100 5ASTM International
