1、Designation: D6320/D6320M 10 (Reapproved 2014)Standard 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 re
2、vision, the year of 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 pro
3、ducts. By agreement,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 liste
4、d below:Property SectionBreaking force (strength) 713Yield strength 713Elongation 713Knot strength 1420Torsion resistance 2127Reverse bend 2834Wrap 3541Diameter 42481.4 The values stated in either SI units or inch-pound unitsare to be regarded separately as standard. The values stated ineach system
5、may not be 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 therespons
6、ibility of 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 Textil
7、esD2969 Test Methods for Steel Tire CordsD4848 Terminology Related to Force, Deformation andRelated Properties of TextilesD6477 Terminology Relating to Tire Cord, Bead Wire, HoseReinforcing Wire, and Fabrics3. Terminology3.1 Definitions:3.1.1 For definitions of terms relating to tire cord, bead wire
8、,hose wire, 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 follo
9、wing terms 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 i
10、nthe appropriate 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 th
11、e procedures 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
12、determine 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
13、. The testspecimens 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
14、 is found, 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 IndustrialFibers and Metallic Reinforcements.Current edition approved May 15, 20
15、14. Published June 2014. Originallyapproved in 1998. Last previous edition approved in 2010 as D6320 10. DOI:10.1520/D6320_D6320M-10R14.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume in
16、formation, refer to the standards Document Summary page onthe ASTM website.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States1supplier must agree to interpret future test results with consid-eration to the known bias.6. Sampling6.1 Lot S
17、ampleAs a lot sample for acceptance testing, takeat random the number of reels, coils, spools, or other shippingunits of wire directed in an applicable material specification orother agreement between purchaser and supplier. Considerreels, coils, spools, or other shipping units of wire to be theprim
18、ary sampling units.NOTE 1A realistic 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 meaningfulproduc
19、ers risk and acceptable quality level.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 test
20、procedure.BREAKING FORCE, YIELD STRENGTH, 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
21、increasing forces applied until the specimen 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 extension
22、at break divided by the original specimen 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 calculating
23、elongation and yield strength using a 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 st
24、rength are used inengineering calculations 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 T
25、esting Machine, constant rate of extension(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 con
26、form to Specification D76.10.2 In some 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 de
27、vice that can be attached to thespecimen 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
28、 a proper force-scale range on the tensile 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
29、speed at 250 mm/min. 10 in./min.11.4 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 se
30、cure the other end in the lowergrip.11.6 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-exten
31、sion curve generated.11.7.1 If the specimen 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 l
32、iner extends beyond thegrip edge where 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 c
33、urve.11.11 Yield Strength Determine the 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 OAD6320/D6320M 10 (2014)2and locate r. Th
34、is intersection of mn with the force-extensioncurve corresponds 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.12. Calculation12
35、.1 Break Strength Calculate the average breaking 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
36、 theforce-extension curve exhibit an initial 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.
37、12.2.2 Calculate the average elongation at break 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 thes
38、etest methods (D6320) for breaking strength, 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 purchas
39、er and the supplier,13.2.2 Type of tensile test 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
40、tensile: 2750 MN/m2to3050 MN/m2 brass plated 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 repeat
41、ability standard deviation forelongation has 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
42、 a test method.KNOT STRENGTH15. Scope15.1 This 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 a
43、nd Use16.1 Complex stress and strain conditions 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 gri
44、ps as describedin Section 10. Electronic recording 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 outafte
45、r aging for 1 h 6 5 min at 150 6 5C 300 6 9F.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
46、grips. Secure one end ofthe specimen in the upper grip sufficiently to prevent slippageduring testing. While keeping the specimen taut, place andsecure the other end in the lower grip.18.6 After setting the crosshead speed at 25 mm/min 1in./min and the recorder chart at 25 mm/min. 1 in./min, startth
47、e 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.and load to fracture.FIG. 1 Force-Extension Curve for Determination of Yield Strengthby the Offset MethodD6320/D6320M 10 (2014
48、)318.8 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 fromeach laborato
49、ry 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 were perfor
