《JIS-H-7501-2002-R2007-ENG.pdf》由会员分享，可在线阅读，更多相关《JIS-H-7501-2002-R2007-ENG.pdf（12页珍藏版）》请在三一文库上搜索。
1、J IS JAPANESE I N DUSTR IAL STANDARD Translated and Published by Ja pa nese Standards Association (OSTEC/ JSA) Method for evaluation of tensile properties of metallic superplastic materials ICs 77.040.10 Reference number : JIS H 7501 : 2002 (E) PROTECTED BY COPYRIGHT 7s Copyright Japanese Standards
2、Association Provided by IHS under license with JSALicensee=IHS Employees/1111111001, User=Japan, IHS Not for Resale, 02/16/2008 02:19:15 MSTNo reproduction or networking permitted without license from IHS -,-,- H 7501 : 2002 Foreword This translation has been made based on the original Japanese Indu
3、strial Standard established by the Minister of Economy, Trade and Industry through deliberations at the Japanese Industrial Standards Committee according to the proposal of establishing a Japanese Industrial Standard from the Foundation of Osaka Science Strain rate obtained by divid- ing the cross-h
4、ead velocity by the original gauge length. Industrial superplastic strain rate S-l Strain rate practically used for superplastic forming by interested parties. KSP Industrial superplastic deformation stress Superplastic elongation N/mm2 or MPa Deformation stress at superplastic strain rate practical
5、ly used for superplastic forming. Elongation at fracture in a superplastic state. % 6 Gauge length L O mm Initial distance between gauge marks measured by appropriate apparatus with the accuracy of at least 0.5 %. Distance between gauge marks measured after fracture with fracture surfaces getting to
6、gether with care so that the center line of either fracture surface is on a single straight line. Force at ten percent elongation. Gauge length after fracture mm Ten percent deforma- tion force P N Initial cross-sectional area of test piece Ao mm2 Initial cross-sectional area of a test piece meas- u
7、red by an appropriate apparatus with the accuracy of at least 0.5 %. 4 Test piece The test piece shall be, in principle, a flat form with a flat parallel portion or a bar form. Its shape and dimensions are given in Figs. 1 and 2, and Tables 2 and 3, respectively. The application thickness of a flat
8、form test piece shall be the same as the plate thickness of the material to be used. The dimensional tol- erance of a test piece is provided in JIS Z 2201. PROTECTED BY COPYRIGHT Copyright Japanese Standards Association Provided by IHS under license with JSALicensee=IHS Employees/1111111001, User=Ja
9、pan, IHS Not for Resale, 02/16/2008 02:19:15 MSTNo reproduction or networking permitted without license from IHS -,-,- 3 H 7501 : 2002 Designation 518 Fig. 1 Shape of flat form test piece (S-type) Gauge length Parallel portion Parallel portion Radius of fillet L O L W R 18 Not less than 18 6 Not mor
10、e than 3 length width Table 2 Dimensions of S-type test piece Unit : mm 1 - - 1 Fig. 2 Shape of bar form test piece (5-type) PROTECTED BY COPYRIGHT Copyright Japanese Standards Association Provided by IHS under license with JSALicensee=IHS Employees/1111111001, User=Japan, IHS Not for Resale, 02/16/
11、2008 02:19:15 MSTNo reproduction or networking permitted without license from IHS -,-,- 4 H 7501 : 2002 Designation Gauge length Parallel portion length L O L B 18 18 Not less than 18 Parallel portion Radius of fillet diameter D R 6 Not more than 3 5 Apparatus Test tem- perature 5 . 1 The machine us
12、ed shall satisfy the condition of constant cross-head velocity. Testing machine The testing machine used shall conform to JIS B 7721. Not more than 473 5.2 Gripping device for test pieces The gripping device shall be rigid so as to avoid being plastically deformed during elevated temperature testing
13、. A recommendable method will be described in 6 a). Over 473 up to and incl. 873 i 3 5.3 Heating apparatus A heating furnace with a thermoregulator shall be used for heating test pieces. During a test the furnace shall be capable of keeping all over the gauge length of the test piece uniformly and c
14、onstantly within the allow- able range of Table 4. Over 873 Over 1 073 Over 1 273 up to and up to and incl. 1073 incl. 1273 +4 t 5 Agreed by interested parties Table 4 Allowable range of test temperature Unit: K range interested parties 5.4 Atmosphere The test shall be conducted in environments whic
15、h can protect the test piece and the gripping device from oxidation effect. In case of the test with the test piece sealed in a vacuum or nitrogen or inert gas vessel, the measuring load should be corrected for the actual value. 5.5 Thermometric apparatus The thermometric apparatus consists of a mea
16、- suring device and a thermocouple. a) Measuring device The measuring device used shall be capable of measuring the temperature of the test piece within the allowable range of 5 . 3 over the entire temperature range to be measured. Thermocouple The thermocouple shall basically conform with JIS C 160
17、2. Also, the materials used for thermocouple shall be capable of enduring the service tem- perature and environment. It is preferable to use Pt/Pt-Rh thermocouple. b) PROTECTED BY COPYRIGHT Copyright Japanese Standards Association Provided by IHS under license with JSALicensee=IHS Employees/11111110
18、01, User=Japan, IHS Not for Resale, 02/16/2008 02:19:15 MSTNo reproduction or networking permitted without license from IHS -,-,- 5 H 7501 : 2002 When a thermometer other than a thermocouple is used, it shall be equally or more accurate than a thermocouple. 6 Procedure 783 and the rest are as follow
19、s. Test procedures shall be in accordance with JIS Z 2241 and IS0 a) Method for gripping test piece Fix the test piece with a gripping device so that only axial force is applied on the test piece during the test. In the case of the flat form test piece, gripping and firmly fixing the test piece are
20、achieved by directly contacting the surface of the test piece with the serrated surface of gripping device, passing an alignment pin through the pin hole in the test piece using bolt screw and so on. In the case of the bar form test piece, fixing the test piece is achieved by threading the test piec
21、e to gripping portion and the machine fixing portion. Measurement of the test temperature The measurement of the test tem- perature shall conform to JIS Z 8704. The temperature to be measured should be that of the test piece. However, such measurement may be flexible if tern- perature variation of t
22、he test piece is known through experience in a generally prepared heating furnace. In this case, the test temperature to be measured shall be that of the atmosphere under conditions that the measuring point of the thermocouple well contacts the surface of the test piece for good heat-con- duction an
23、d that direct radiation of heat from the furnace wall is properly shielded. Interested parties shall agree on the time of heating the test piece to the test temperature and the holding time at the test temperature before starting the test, provided that such agreement shall be made with a full assur
24、ance of uniform temperature distribution on the test piece. The test temperature shall be maintained within the allowable range speci- fied in 5.3 during the test. Application of the force cross-head velocity during deformation. b) c) Force shall be applied under prescribed constant d) Method for di
25、mensional measurement of test pieces The dimension of the gauge portion of the test piece shall be measured by adequate measuring equipment with a precision of at least 0.5 % of specified dimension. e) Method for determining the superplastic elongation The gauge length prior to the test shall be 18
26、mm. The length shall be measured with a preci- sion of at least 0.5 % by an adequate measuring equipment. The superplastic elongation shall be determined by the following equation. The value shall be rounded off to two significant figures according to JIS Z 8401. where, S : superplastic elongation (
27、%) L, : gauge length after fracture (mm) L o : gauge length (mm) PROTECTED BY COPYRIGHT Copyright Japanese Standards Association Provided by IHS under license with JSALicensee=IHS Employees/1111111001, User=Japan, IHS Not for Resale, 02/16/2008 02:19:15 MSTNo reproduction or networking permitted wit
28、hout license from IHS -,-,- 6 H 7501 : 2002 Determination of flow stress The force-elongation diagram in superplastic de- formation shall be drawn by measuring changes in force against elongation dur- ing a test with adequate measuring equipment, provided that the force measured in a superplastic co
29、ndition satisfies the precision of the load cell. Ten percent flow stress osSp shall be given by the following equation, where the force is that when ten percent elongation is achieved. 1.w o , , = - A O where, osCp : ten percent flow stress (N/mm2) P : ten percent deformation force (N) AO : initial
30、 cross-sectional area of test piece (mm2) In the region of low strain rate (low stress region), a large measurement error of flow stress occurs, which is caused by a lack of precise force measurement; this adversely affects the calculation of the rn value and the Kvalue. Since the cross-sectional ar
31、ea of the test piece is small, the maximum force is about 1 kg in the region of low strain rate (or low stress region). Therefore it is recom- mended that a load cell with maximum force of 10 N to 100 N or less be used to improve the precision of force measurement. (See Informative reference Fig. 1)
32、. Informative reference : Strain rate, s- Informative reference Fig. 1 Example of the relationship between stress and strain rate in a superplastic 7475 alloy Determination of strain rate sensitivity exponent (rn value) The tests with five or more different cross-head velocities shall be conducted a
33、nd the re- lationship between ten percent flow stress at each cross-head velocity and the corresponding strain rate should be plotted in a log-log scale. Linear regres- sion should be applied to such relationship by method of least squares, and round PROTECTED BY COPYRIGHT Copyright Japanese Standar
34、ds Association Provided by IHS under license with JSALicensee=IHS Employees/1111111001, User=Japan, IHS Not for Resale, 02/16/2008 02:19:15 MSTNo reproduction or networking permitted without license from IHS -,-,- H 7501 : 2002 off the m value, which is the slope of a straight line, to the first dec
35、imal place according to JIS 2 8401. The region of superplastic strain rate shall be en- sured that the superplastic (fracture) elongation of at least 300 % is attainable. In addition, it is desirable that the minimum and the maximum superplastic strain rates differ 100 times or more. Determination o
36、f the Ksp value The Ksp value is calculated by the following equation: h) where, Ksp : superplastic deformation stress (N/mm2) oSp : ten percent flow stress (N/mm2) i s , : superplastic strain rate (s-1) E : strain rate (s-1) m : strain rate sensitivity exponent 7 Report are applicable. The test rep
37、ort shall include the following information as far as they Test materials 1) Manufacturer 2) Designation of materials 3) Kind or mark 4) Manufacturing lot number Dimensions of the test piece Description of test equipment Test conditions 1) Test temperature 2) Cross-head velocity 3) Test atmosphere 4
38、) Heating rate 5) 6) Test results 1) Superplastic elongation 2) Ten percent flow stress 3) m value 4) Ksp value Holding time prior to testing Sampling position and direction of test pieces PROTECTED BY COPYRIGHT Copyright Japanese Standards Association Provided by IHS under license with JSALicensee=
39、IHS Employees/1111111001, User=Japan, IHS Not for Resale, 02/16/2008 02:19:15 MSTNo reproduction or networking permitted without license from IHS -,-,- 8. H 7501 : 2002 5) 6) Additional items 1) Chemical composition of materials 2) Fabrication of materials 3) Heat-treatment of materials 4) Grain siz
40、e of materials 5) Relationship between nominal stress and nominal strain Relationship between ten percent flow stress and strain rate f, It is desirable to include the following information: Mechanical properties of materials at room temperature PROTECTED BY COPYRIGHT Copyright Japanese Standards As
41、sociation Provided by IHS under license with JSALicensee=IHS Employees/1111111001, User=Japan, IHS Not for Resale, 02/16/2008 02:19:15 MSTNo reproduction or networking permitted without license from IHS -,-,- Errata for J?S (English edition) are printed in Standardization Jouml, pubfished monthly by
42、 the Japanese Standards Association, and also provided to subscribers of JS (English edition) in Monthly Information. E r r a t a will be provided upon request, please contact: Standardization Promotion Departmen& Japanese Standards Association 4-1-24, Aicasaka, Minato-ku, Tokyo, 107-8440 JAPAN TEL.
43、 03-3583-8002 FAX. 03-3583-0462 l“/, Recycled paper PROTECTED BY COPYRIGHT Copyright Japanese Standards Association Provided by IHS under license with JSALicensee=IHS Employees/1111111001, User=Japan, IHS Not for Resale, 02/16/2008 02:19:15 MSTNo reproduction or networking permitted without license from IHS -,-,-