1、Designation: E 604 83 (Reapproved 2002)Standard Test Method forDynamic Tear Testing of Metallic Materials1This standard is issued under the fixed designation E 604; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last r
2、evision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon (e) indicates an editorial change since the last revision or reapproval.This standard has been approved for use by agencies of the Department of Defense.1. Scope1.1 This test method covers the dynamic tear (
3、DT) test usingspecimens that are316 in. to58 in. (5 mm to 16 mm) inclusivein thickness.1.2 This test method is applicable to materials with aminimum thickness of316 in. (5 mm).1.3 The pressed-knife procedure described for sharpeningthe notch tip generally limits this test method to materials witha h
4、ardness level less than 36 HRC.NOTE 1The designation 36 HRC is a Rockwell hardness number of36 on Rockwell C scale as defined in Test Methods E18.2. Referenced Documents2.1 ASTM Standards:B 221 Specification for Aluminum-Alloy Extruded Bars,Rods, Wire,2E18 Test Methods for Rockwell Hardness and Rock
5、wellSuperficial Hardness of Metallic Materials3E 399 Test Method for Plane-Strain Fracture Toughness ofMetallic Materials33. Terminology3.1 Description of Terms Specific to this Standard3.2 Dynamic Tear (DT) Energythe total energy requiredto fracture DT specimens tested in accordance with theprovisi
6、ons of this test method.NOTE 2With pendulum-type machines, the DT energy is the differ-ence between the initial and the final potential energies of the pendulumor pendulums.NOTE 3With drop-weight machines, the DT energy is the differencebetween the initial potential energy of the hammer and the fina
7、l energy ofthe hammer as determined by a calibrated energy measurement system.3.3 Percent Shear Fracture AppearancePercent shearfracture appearance is the percent of the net section thatfractured in a shear mode. Net section can be either the netsection area before fracture or the area of the projec
8、ted plane ofthe fracture surface.4. Summary of Test Method4.1 The DT test involves a single-edge notched beam that isimpact loaded in three-point bending, and the total energy lossduring separation is recorded.4.2 The DT specimens are fractured with pendulum ordrop-weight machines.5. Significance an
9、d Use5.1 The DT energy value is a measure of resistance to rapidprogressive fracturing. In a number of applications, the en-hanced resistance that may develop during about one platethickness of crack extension from a sharp notch is of majorinterest. In the test method, a sufficiently long fracture p
10、ath isprovided so that the results serve as a measure of this property.5.2 Fracture surfaces of nonaustenitic steels tested in theirtemperature transition region have areas that appear bright andareas that appear dull. The bright, faceted appearing areas aretermed “cleavage” fracture, and the dull a
11、ppearing areas aretermed “shear” fracture after their respective mode of fractureon a micro scale.5.3 This test method can serve the following purposes:5.3.1 In research and development, to evaluate the effects ofmetallurgical variables such as composition, processing, orheat treatment, or of fabric
12、ating operations such as forming andwelding on the dynamic tear fracture resistance of new orexisting materials.1This test method is under the jurisdiction ofASTM Committee E28 on FractureTesting and is the direct responsibility of Subcommittee E28.07 on Impact Testing.Current edition approved March
13、 25, 1983. Published July 1983. Originallypublished as a proposed test method in November 1975. Last previous editionE 604 80.2Annual Book of ASTM Standards, Vol 02.02.3Annual Book of ASTM Standards, Vol 03.01.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 1
14、9428-2959, United States.5.3.2 In service evaluation, to establish the suitability of amaterial for a specific application only where a correlationbetween DT energy and service performance has been estab-lished.45.3.3 For information, specifications of acceptance, andmanufacturing quality control wh
15、en a minimum DT energy isrequested. Detailed discussion of the basis for determiningsuch minimum values in a particular case is beyond the scopeof this test method.6. Apparatus6.1 General RequirementsThe testing machine shall beeither a pendulum type or a drop-weight type of capacity morethan suffic
16、ient to break the specimen in one blow. DT energyvalues above 80 % of the initial potential energy of the bloware invalid. The capacity needed to conduct DT tests on moststeels is 2000 ftlbf (2700 J) for58-in. (16-mm) and 500 ftlbf(700 J) for316-in. (5-mm) thick specimens. The capacityneeded to cond
17、uct DT tests on the cast irons and aluminumalloys is less than 20 % of the values given above for moststeels.6.1.1 Velocity LimitationsTests may be made at velocitiesthat range from 13 to 28 ft/s (4.0 to 8.5 m/s). Velocity shall bestated as the velocity between the striker and the specimen atimpact.
18、 This range in velocities corresponds to that of hammersdropped from heights of 32 in. to 12 ft (0.8 to 3.7 m).6.1.2 The impact machine shall have a calibrated scale,charts, or direct reading-indicator of initial and final energyvalues, or the difference between the initial and final energyvalues. T
19、he scale, chart, or direct-reading indicator shall bedivided so that DT energy values can be estimated within thefollowing increments:DT Energy Value Maximum Increment600 ftlbf (800 J) 30 ftlbf (40 J)6.1.2.1 The error in the DT energy value due to an error inthe weight of the pendulum or the droppin
20、g weight, or due toan error in drop height, shall not exceed 1 %. Windage andfriction may be compensated for by increasing the height of thedrop, in which case the height may exceed the nominal valueby not over 2.0 %.6.1.3 The specimen anvil and the striker tup shall be of steelhardened to a minimum
21、 hardness value of 48 HRC and shallconform to the dimensions presented in Fig. 1. Clearancebetween the sides of the hammer and anvil shall not be lessthan 2.0 in. (51 mm), and the center line of the striker edgeshall advance in the plane that is within 0.032 in. (0.80 mm) ofthe midpoint between the
22、supporting edges of the specimenanvils. The striker edge shall be perpendicular to the longitu-dinal axis of the specimen within 0.01 rad. When in contactwith the specimen, the striker edge shall be parallel within0.005 rad to the face of a square test specimen held against theanvil. Specimen suppor
23、ts for pendulum machines shall besquare with anvil faces within 0.0025 rad. Specimen supportsshall be coplanar within 0.005 in. (0.125 mm) and parallelwithin 0.002 rad.6.2 The design of the pendulum impact machines shallposition the center of percussion at the center of strike within1 % of the dista
24、nce from the center of rotation to the center ofthe strike. When hanging free, the pendulums shall hang so thatthe striking edge is less than 0.20 in. (5.0 mm) from the edgeposition of the specimen.6.2.1 The location of the center of percussion may bedetermined as follows: Using a stop watch or some
25、 othersuitable timer to within 0.2 s, swing the pendulum through atotal angle not greater than 15, and record the time for 100complete cycles (to and fro). Determine the center of percus-sion as follows:l 5 0.815r2, to determine l in feet (1)l 5 0.2485r2, to determine l in metreswhere:l = distance f
26、rom the axis to the center of percussion, ft (orm), andr = time of a complete cycle (to and fro) of the pendulum,s.6.2.2 For double-pendulum machines, the center of percus-sion of each pendulum shall be determined separately.7. Safety Hazards7.1 A safety screen shall surround the anvil to restrict t
27、heflight of broken specimens.4See Pellini, W. S., “Analytical Design Procedures for Metals of Elastic-Plasticand Plastic Fracture Properties,” Welding Research Council Bulletin 186, August1973.Dimensions and Tolerance for Specimen BlankParameter Units Dimension ToleranceLength, L in. 7.125 60.125mm
28、181 63Width, W in. 1.60 60.10mm 41 62Thickness, B in. 0.625 60.035mm 16 61Angularity, a deg 90 61NOTE 1See 9.1 for specimens less than58-in. (16 mm) thick.FIG. 1 Dynamic Tear Test Specimen, Anvil Supports, and StrikerE 604 83 (2002)27.2 Precautions shall be taken to protect personnel fromswinging pe
29、ndulums, dropping weights, flying broken speci-mens, and hazards associated with specimen warming andcooling media.8. Sampling8.1 Notation of the orientation of base metal specimensshall be in accordance with that recommended in Test MethodE 399.8.2 If the thickness of the product is greater than58
30、in. (16mm), then a58-in. (16-mm) thick specimen shall be thestandard specimen.9. Test Specimens9.1 Size of SpecimensThe specimen blank shall be B by1.60 by 7.125 in. ( B by 40.6 by 181.0 mm) where B can befrom316 to58 in. (5 to 16 mm). The tolerances for thesedimensions are presented in Fig. 1.9.2 N
31、otch DetailThe notch is machined to provide afracture path in test material of 1.125 in. (28.5 mm); the smallextension required for notch sharpening is considered a portionof the nominal net section. Details of the notch are shown inFig. 2, and the notch dimensions shall conform to the valuesgiven t
32、herein.9.3 Procedure for Preparing Notch:9.3.1 Rough MachiningMachine a notch to the dimen-sions shown in Fig. 2. The angular apex portion and particu-larly the final cut on the root radius can be machined with aprecisely ground saw, cutter, electric discharge machine, or anyother machining process
33、that will ensure a final root radius lessthan 0.005 in. (0.13 mm). These machining operations arenormally performed simultaneously for a group of specimens.9.3.2 Pressing Notch TipPressing the sharp tip of thenotch to the dimensions prescribed in Fig. 2 is performed onindividual specimens. The impre
34、ssion is made with a blade ofhigh-speed tool steel (60 HRC min), which has been ground tothe dimensions presented in Fig. 3, and subsequently honed toremove any burrs or rough edges. Any loading device withsufficient capacity to press the knife to the prescribed depthmay be used. The force required
35、to accomplish the pressing isrelated to the hardness and the thickness of the specimen. Theforce required can be approximated by either of the followingformulas:force lbf!547 3 ultimate tensile strength ksi!3B in.!force N!52.9 3 ultimate tensile strength MPa!3B mm!where B = thickness of the specimen
36、.NOTE 4Suggested practices for measuring the pressed tip and forpressing the notch tip are given in the Appendixes.10. Calibration of Apparatus10.1 Single-Pendulum MachineSupport the pendulumhorizontally (90 6 1 from the rest position) at a point mostconvenient to react with a weighing device such a
37、s a platformscale, balance, or load cell, and determine the weight within0.4 %. Take care to minimize friction at the bearing supportand the weighing support. Measure the length of the momentarm (that is, the horizontal distance between the center ofrotation and a vertical line that passes through t
38、he point ofsupport) within 0.1 %. The potential energy at any angularposition can be calculated from the following formula:Energy 5 weight 3 moment arm 1 2 cos b!where b = the angle displaced when the pendulum is rotatedfrom the position of rest when hanging free. An alternativeprocedure may be used
39、 if the distance between the center ofrotation and the center of gravity is known within 0.1 %. Theweight is then determined within 0.4 %, with the pendulumsupported horizontally at a point in line with the center ofgravity. The potential energy at any position is equal to theweight times the elevat
40、ion of the center of gravity from the restposition.10.1.1 The friction and windage loss of energy in themachine shall not exceed 2.0 % of the initial energy. Thefriction and windage loss is the difference between the poten-tial energy of the pendulum from the starting position and thepotential energ
41、y of the pendulum after it completes its swingwithout a specimen. Compensate the friction and windage lossso that zero energy is indicated when the pendulum is releasedwithout a specimen being present.10.1.2 Impact VelocityDetermine the impact velocity, v,of the machine, neglecting friction as follo
42、ws:v 5 2 gh!1/2where:g = acceleration of gravity, ft/s2(or m/s2),h = initial elevation of the striking edge, ft (or m), andv = striking velocity, ft/s (or m/s).Dimensions and Tolerances for Notch TipParameter Units Dimension ToleranceNet width, (Wa) in. 1.125 60.020mm 28.6 60.5Machined notch width,
43、Nwin. 0.0625 60.005mm 1.59 60.13Machined notch root angle, Nadeg 60 62Machined notch root radius, Nrin. 0.005 maxPressed tip depth, tDmm 0.13 maxin. 0.010 60.005Pressed tip angle, tamm 0.25 60.13Pressed tip root radius, trdeg 40 65in. 0.001 maxmm 0.025 maxFIG. 2 Details of the Notch in a Dynamic Tea
44、r SpecimenE 604 83 (2002)310.2 Double-Pendulum MachineThe procedure for cali-brating the hammer pendulum and the anvil pendulum shall bein accordance with the procedure in 10.1 for a single-pendulummachine. Calibrate the anvil pendulum without a specimen inplace.10.2.1 Determine and compensate the f
45、riction and windageloss of energy in accordance with the procedure described in10.1.1.10.3 Vertical Drop-Weight Apparatus The dimensions ofthe apparatus shall be such that the falling hammer travels aminimum vertical distance of 2 in. (51 mm) after contacting thespecimen before measurement is made o
46、f the final energy and2.75 in. (70 mm) before an arresting device is activated, asshown in Fig. 4.10.3.1 Calibration of an aluminum block system is requiredfor each lot of blocks machined from a single bar. Segregateand mark for identification purposes blocks that have beenprepared from each bar. Th
47、e initial cross-sectional area ofblocks from one lot shall not vary more than 0.2 %. Determinethe average height of the blocks before and after test and recordwith an error not to exceed 0.0005 in. (0.013 mm). Develop achart of absorbed energy versus deformation of blocks byconducting duplicate test
48、s without a specimen at height incre-ments not to exceed 1 ft (305 mm) through the calibratedrange. Average the deformation values for the two blocks fromeach test; the average values for each height position shallagree within 0.003 in. (0.075 mm). Calculate the absorbedenergy as the weight of the h
49、ammer times the height from thetop surface of the aluminum blocks to the surface of thehammer that strikes the aluminum blocks. Construct a graph ofabsorbed energy versus the deformation of the aluminumblocks as a smooth curve through the data points in thecalibrated range. The dimensions of the aluminum blocks shallbe such that the stiffness of a single block at any point in thecalibrated range shall be as follows:DT Energy Value Stiffness per Block50 ftlbf (74 J) and under 1 ftlbf/0.001 in. (54 J/mm)greater than 50 ftlbf (74 J) 2.5 ftlbf
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