1、Designation: D 6320 04Standard Test Methods forSingle Filament Hose Reinforcing Wire Made from Steel1This standard is issued under the fixed designation D 6320; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revis
2、ion. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon (e) 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 agreement,these tes
3、t 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 SectionBreak
4、ing force (strength) 7-13Yield strength 7-13Elongation 7-13Knot strength 14-20Torsion resistance 21-27Reverse bend 28-34Wrap 35-41Diameter 42-481.4 These test methods are written in SI units; the inch-pound units which are provided are not necessarily exactequivalents of the SI units. Either system
5、of units may be usedin these test methods. In the case of referee decisions, the SIunits will prevail.1.5 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 he
6、alth practices and determine the applica-bility of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:2D 76 Specification for Tensile Testing Machines for TextilesD 123 Terminology Relating to TextilesD 2969 Methods for Testing Filaments, Strands, Cords, andFabrics Made fr
7、om SteelD 4848 Terminology of Force, Deformation and RelatedProperties of TextilesD 6477 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, and tire cord fabrics, refer
8、 to Terminology D 6477.3.1.1.1 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 D 4848.3.1.2.1 The following terms are relevant to this standa
9、rd:breaking force and elongation.3.1.3 For definitions of other terms related to textiles, referto Terminology D 123.4. Summary of Test Method4.1 A summary of the directions prescribed for determina-tion of specific properties of hose reinforcing wire is stated inthe appropriate sections of the spec
10、ific 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 procedures are the bestavailable an
11、d 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 if thereis a statistical bi
12、as 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 testspecimens then should be ra
13、ndomly 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, either its1These test meth
14、ods 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 Oct. 1, 2004. Published October 2004. Originallypublished as D632098. Last previous edition D632002.2For referenced ASTM standards
15、, 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.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19
16、428-2959, United States.cause must be determined and corrected or the purchaser andsupplier must agree to interpret future test results with consid-eration to the known bias.6. Sampling6.1 Lot SampleAs a lot sample for acceptance testing,take at random the number of reels, coils, spools, or othershi
17、pping 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 specification or other agreement between thepurchaser and the suppl
18、ier 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.6.2 Laboratory SampleUse the primary sampling units inthe lot samp
19、le 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 STRENGTH, ANDELONGATION7. Scope7.1 This test method covers the measureme
20、nt 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 specimen breaks. Thechange in force is measured versus the increase
21、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 specimen length times 100.Yield strength the intersection of the force-
22、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 programmed computer.9. Significance and Use9.1 The load bearing ab
23、ility 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 calculations when designing this type of reinforcedproduct.9.2 Elongation
24、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 extension(CRE) type tensile testing machine of such capacity that thema
25、ximum 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 D 76.10.2 In some laboratories, the output of CRE type of tensiletesting machine i
26、s 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 thespecimen and that permits recording of the specimen extensionduring loa
27、ding, 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 tensile testingmachine based on the estimated breaking force of the
28、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 Adjust the distance between the grips of the tensilemachine,
29、 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.11.6 Apply a force of no greater than 1 N (0.2 lbf) on thec
30、lamped 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 specimen fractures at, or within, 5 mm (0.2 in.)of the gri
31、pping 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 where it comes in contact with the specimen.11.8 Conduct t
32、his 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 the yield strength by the0.2 % offset method.11.11.1 On
33、 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 corresponds to force R, that is the yield strength. Shouldthe
34、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.D632004212. Calculation12.1 Break Strength Calculate the average breaking forcefor each laboratory sampling unit to the nearest 1 N
35、 (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 nonlinear portion,extrapolate from the straight line portio
36、n 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 break for eachlaboratory sampling unit.12.3 Yield Strength Ca
37、lculate 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 (D 6320) for breaking strength, elongation atbreak and yield strength. Describe the mate
38、rial 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 test machine, machine number (ifapplicable), and rate of e
39、xtension,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 hose wire was tested. The singleoperator repeatability
40、 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 been determined to be 0.14 %. The reproduc-ibility of
41、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 This section describes the test procedure to determinethe
42、 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 conditions sensitive to varia-tion in materials occur in
43、 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 recording and computing equipmentis optional.18. Pro
44、cedure18.1 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).18.3 Adjust the distance between the grips of
45、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 upper grip sufficiently to prevent slippagedu
46、ring 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 TestD632004318.6 After setting the crosshead speed at 25
47、 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. and load tofracture.18.8 If the specimen fractures at or wi
48、thin 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 laboratory sampling unit.18.10 Determine the br
49、eaking 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 performed as directed in thistest methods (D 6320). Describe the material or product testedand
