1、Designation: D6320/D6320M 10Standard Test Methods forSingle Filament Hose Reinforcing Wire Made from Steel1This standard is issued under the fixed designation D6320/D6320M; the number immediately following the designation indicates theyear of original adoption or, in the case of revision, the year o
2、f last revision. A number in parentheses indicates the year of lastreapproval. A superscript epsilon () indicates an editorial change since the last revision or reapproval.1. Scope1.1 These test methods cover testing of single filament steelwires that are used to reinforce hose products. By agreemen
3、t,these test methods may be applied to similar filaments used forreinforcing other rubber products.1.2 These test methods describe test procedures only and donot establish specifications or tolerances.1.3 These test methods cover the determinations of themechanical properties listed below:Property S
4、ectionBreaking force (strength) 7-13Yield strength 7-13Elongation 7-13Knot strength 14-20Torsion resistance 21-27Reverse bend 28-34Wrap 35-41Diameter 42-481.4 The values stated in either SI units or inch-pound unitsare to be regarded separately as standard. The values stated ineach system may not be
5、 exact equivalents; therefore, eachsystem shall be used independently of the other. Combiningvalues from the two systems may result in non-conformancewith the standard.1.5 This standard does not purport to address all of thesafety concerns, if any, associated with its use. It is theresponsibility of
6、 the user of this standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:2D76 Specification for Tensile Testing Machines for TextilesD123 Terminology Relating to TextilesD2969 Te
7、st Methods for Steel Tire CordsD4848 Terminology Related to Force, Deformation andRelated Properties of TextilesD6477 Terminology Relating to Tire Cord, Bead Wire,Hose Reinforcing Wire, and Fabrics3. Terminology3.1 Definitions:3.1.1 For definitions of terms relating to tire cord, bead wire,hose wire
8、, and tire cord fabrics, refer to Terminology D6477.3.1.1.1 The following terms are relevant to this standard:hose reinforcing wire, torsion resistance, yield strength.3.1.2 For definitions of terms related to force and deforma-tion in textiles, refer to Terminology D4848.3.1.2.1 The following terms
9、 are relevant to this standard:breaking force and elongation.3.1.3 For definitions of other terms related to textiles, referto Terminology D123.4. Summary of Test Method4.1 A summary of the directions prescribed for determina-tion of specific properties of hose reinforcing wire is stated inthe appro
10、priate sections of the specific test methods that follow.5. Significance and Use5.1 The procedures for the determination of properties ofsingle-filament hose reinforcing wire made from steel areconsidered satisfactory for acceptance testing of commercialshipments of this product because the procedur
11、es are the bestavailable and have been used extensively in the trade.5.1.1 In the case of a dispute arising from differences inreported test results when using these test methods for accep-tance testing of commercial shipments, the purchaser andsupplier should conduct comparative tests to determine
12、if thereis a statistical bias between their laboratories. Competentstatistical assistance is recommended for investigation of bias.As a minimum, two parties should take a group of testspecimens which are as homogeneous as possible and whichare from a lot of material of the type in question. The test
13、specimens then should be randomly assigned in equal numbersto each laboratory for testing. The average results from the twolaboratories should be compared by using an appropriatestatistical test and an acceptable probability level chosen by thetwo parties before testing is begun. If a bias is found,
14、 either itscause must be determined and corrected or the purchaser and1These test methods are under the jurisdiction of ASTM Committee D13 onTextiles and are the direct responsibility of Subcommittee D13.19 on Tire Cord andFabrics.Current edition approved Jan. 1, 2010. Published February 2010. Origi
15、nallyapproved in 1998. Last previous edition approved in 2004 as D6320 04. DOI:10.1520/D6320-04.2For 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 Docume
16、nt Summary page onthe ASTM website.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.supplier must agree to interpret future test results with consid-eration to the known bias.6. Sampling6.1 Lot SampleAs a lot sample for acceptance tes
17、ting,take at random the number of reels, coils, spools, or othershipping units of wire directed in an applicable materialspecification or other agreement between purchaser and sup-plier. Consider reels, coils, spools, or other shipping units ofwire to be the primary sampling units.NOTE 1A realistic
18、specification or other agreement between thepurchaser and the supplier requires taking into account the variabilitybetween and within primary sampling units, to provide a sampling planwhich at the specified level of the property of interest has a meaningfulproducers risk and acceptable quality level
19、.6.2 Laboratory SampleUse the primary sampling units inthe lot sample as a laboratory sample.6.3 Test Specimens For each test procedure, take thenumber of lengths of hose reinforcing wire of the specifiedlengths from each laboratory sample as directed in the testprocedure.BREAKING FORCE, YIELD STREN
20、GTH, ANDELONGATION7. Scope7.1 This test method covers the measurement of breakingforce, yield strength, and elongation of single filament steelreinforcing wire in a tensile test.8. Summary of Test Method8.1 The specimen is clamped in a tensile testing machineand increasing forces applied until the s
21、pecimen breaks. Thechange in force is measured versus the increase in separation ofthe specimen clamps to form a force-extension curve. Breakingforce is read directly from the curve and is expressed innewtons (pounds - force). Elongation at break is the extensionat break divided by the original spec
22、imen length times 100.Yield strength the intersection of the force-extension curvewith a line at 0.2 % offset, is read from the force-extensioncurve and is expressed in newtons (pounds - force). Currenttensile test machines may have the capability for calculatingelongation and yield strength using a
23、 programmed computer.9. Significance and Use9.1 The load bearing ability of a reinforced rubber productsuch as a steel reinforced hydraulic hose is related to thestrength of the single-filament wire used as the reinforcingmaterial. The breaking force and yield strength are used inengineering calcula
24、tions when designing this type of reinforcedproduct.9.2 Elongation of hose reinforcing wire is taken into con-sideration in the design and engineering of hoses because of itseffect on uniformity and dimensional stability during service.10. Apparatus10.1 Tensile Testing Machine, constant rate of exte
25、nsion(CRE) type tensile testing machine of such capacity that themaximum force required to fracture the wire shall not exceed90 % nor be less than 10 % of the selected force measurementrange. The specifications and methods of calibration andverification shall conform to Specification D76.10.2 In som
26、e laboratories, the output of CRE type of tensiletesting machine is connected with electronic recording andcomputing equipment that may be programmed to calculateand print the results for each of the force - extension properties,optional.10.3 Extensometer, any device that can be attached to thespeci
27、men and that permits recording of the specimen extensionduring loading, optional.10.4 Grips, of such design that failure of the specimen doesnot occur at the gripping point, and slippage of the specimenwithin the jaws (grips) is prevented.11. Procedure11.1 Select a proper force-scale range on the te
28、nsile testingmachine based on the estimated breaking force of the specimenbeing tested.11.2 If specified, tensile testing may be carried out afteraging for 1 h 6 5 min at 150 6 5C 300 6 9F.11.3 Set the crosshead speed at 25 mm/min. 1.0 in./min.and recorder chart speed at 250 mm/min. 10 in./min.11.4
29、Adjust the distance between the grips of the tensilemachine, nip to nip, to a gage length of 250 mm 10 in., 60.5 %.11.5 Secure the specimen in the upper grip sufficiently toprevent slippage during testing. While keeping the specimenstraight and taut, place and secure the other end in the lowergrip.1
30、1.6 Apply a force of no greater than 1 N 0.2 lbf on theclamped specimen to take out any residual slack beforeinitiating the test. This will be considered the zero-referencepoint for elongation calculations.11.7 Start the testing machine and record the force-extension curve generated.11.7.1 If the sp
31、ecimen fractures at, or within, 5 mm 0.2 in.of the gripping point, discard the result and test anotherspecimen. If such jaw breaks continue to occur, insert a jawliner, such as an abrasive cloth, between the gripping surfaceand the specimen in a manner that the liner extends beyond thegrip edge wher
32、e it comes in contact with the specimen.11.8 Conduct this test procedure on two specimens fromeach laboratory sampling unit.11.9 Breaking Force Read the maximum force from theforce-extension curve.11.10 ElongationDetermine the elongation from theforce-extension curve.11.11 Yield Strength Determine t
33、he yield strength by the0.2 % offset method.11.11.1 On the force-extension curve (see Fig. 1) that hasbeen generated (see 11.7), lay off Om equal to the specifiedvalue of the offset (0.2 % elongation): draw mn parallel to OAand locate r. This intersection of mn with the force-extensioncurve correspo
34、nds to force R, that is the yield strength. Shouldthe force-extension curve exhibit an initial nonlinear portion,extrapolate from the straight line portion to the base line. Thisintersection is point 0 used in this section.D6320/D6320M 10212. Calculation12.1 Break Strength Calculate the average brea
35、king forcefor each laboratory sampling unit to the nearest 1 N 0.2 lbf,and record this value as breaking strength.12.2 Elongation at Break:12.2.1 Calculate the elongation at break for each specimenfrom the force-extension curve to the nearest 0.1 %. Should theforce-extension curve exhibit an initial
36、 nonlinear portion,extrapolate from the straight line portion of the curve to thebase line. This intersection is the point of origin for theelongation determination. The extension from this point to theforce at the point of rupture is the total elongation.12.2.2 Calculate the average elongation at b
37、reak for eachlaboratory sampling unit.12.3 Yield Strength Calculate the average yield strengthfrom each laboratory sampling unit as directed in Section11.11.1 to the nearest 1 N 0.2 lbf.13. Report13.1 State that the tests were performed as directed in thesetest methods (D6320) for breaking strength,
38、 elongation atbreak and yield strength. Describe the material or producttested.13.2 Report the following information:13.2.1 The test results of each specimen and the laboratorysample average. Calculate and report any other data agreed tobetween the purchaser and the supplier,13.2.2 Type of tensile t
39、est machine, machine number (ifapplicable), and rate of extension,13.2.3 Whether specimens were heat aged or not,13.2.4 Any deviation from the standard test procedure, and13.2.5 Date of test and operator.14. Precision and Bias14.1 Precision0.30 mm HT high tensile: 2750 MN/m2to3050 MN/m2 brass plated
40、 hose wire was tested. The singleoperator repeatability standard deviation for breaking force hasbeen determined to be 8.24N. The single operator repeatabilitystandard deviation for yield strength has been determined to be5.24 N. The single operator repeatability standard deviation forelongation has
41、 been determined to be 0.14 %. The reproduc-ibility of this test method is being determined and will beavailable before 2005.14.2 BiasThe tensile property procedures of these testmethods have no bias, because these properties can be definedonly in terms of a test method.KNOT STRENGTH15. Scope15.1 Th
42、is section describes the test procedure to determinethe knot test characteristic of hydraulic hose wire with adiameter less than or equal to 0.82 mm 0.032 in. In practice,the knot test is most suitable for wires less than 0.50 mm 0.020in.16. Significance and Use16.1 Complex stress and strain conditi
43、ons sensitive to varia-tion in materials occur in wire specimens during knot strengthtesting. The knot strength test is a useful tool in assessing wireductility as defective wire lowers knot strength.17. Apparatus17.1 Tensile Test Machine, CRE-type and grips as describedin Section 10. Electronic rec
44、ording and computing equipmentis optional.18. Procedure18.1 Select a proper force-scale range on the tensile testingmachine based upon the estimated breaking force of thespecimen being tested.18.2 If specified, the knot strength test may be carried outafter aging for 1 h 6 5 min at 150 6 5C 300 6 9F
45、.18.3 Adjust the distance between the grips of the tensiletesting machine, nip to nip, to a gage length of 250 mm 10 in.6 0.5 %.18.4 Form a simple loop (overhand) knot in the middle zoneof the test piece as shown in Fig. 2.18.5 Center the knot between the grips. Secure one end ofthe specimen in the
46、upper grip sufficiently to prevent slippageduring testing. While keeping the specimen taut, place andsecure the other end in the lower grip.FIG. 1 Force-Extension Curve for Determination of Yield Strengthby the Offset MethodFIG. 2 Overhand Knot, (a) As Tied and (b) As Tightened Duringthe TestD6320/D
47、6320M 10318.6 After setting the crosshead speed at 25 mm/min 1in./min and the recorder chart at 25 mm/min. 1 in./min, startthe testing machine and record the force-extension curvegenerated.18.7 When the knotted diameter reaches about 5 mm 0.2in., change the crosshead speed to 10 mm/min 0.4 in./min.a
48、nd load to fracture.18.8 If the specimen fractures at or within 5 mm 0.2 in. ofthe gripping point, discard the result and test another specimen.If such jaw breaks continue to occur, see 11.7.1 for techniquesto minimize the occurrence of such failures.18.9 Conduct this test procedure on two specimens
49、 fromeach laboratory sampling unit.18.10 Determine the breaking strength sample average ofthe wire (Fm) as in Section 12.19. Calculation19.1 Knot Breaking StrengthRead the maximum force(Fkn) for each knotted wire from the force-extension charts tothe nearest 1 N 0.2 lbf.19.2 Knot Strength RatioCalculate the knot strength ratiofor each specimen using Eq 1.Kn 5 100 Fkn/Fm(1)where:Kn = knot strength ratio, %Fkn= knot breaking strength, N lbf, andFm= breaking strength of the wire, N lbf.20. Report20.1 State that the tests w
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