【AS澳大利亚标准】AS 250512004 Metallic materials Method 1 Sheet, strip and plate—Bend tests.doc

Australian StandardTM1 AS 2505.12004 Standards AustraliaAccessed by UNIVERSITY OF SOUTH AUSTRALIA on 27 Feb 2007AS 2505.12004Metallic materialsMethod 1: Sheet, strip and plateBend testsPREFACEThis Standard was prepared by Standards Australia Committee MT-006, Mechanical Testing of Metals to supersede AS 2505.11981, Methods for bend and related testing of metals, Method 1: Sheet, strip and plate.The objective of this revision is to introduce new testing methods of bending coated and uncoated metal sheet, strip and plate.This Standard is Part 1 of a series of Standards on the methods of bending wire and related testing of metals. The series comprises the following:AS2505Metallic materials2505.1Method 1: Sheet, strip and plateBend tests (this Standard)2505.2Method 2: Bars, rods and solid shapesBend tests2505.3Method 3: Tubular productsBend and related tests2505.4Method 4: WireReverse bend test2505.5Method 5: WireSimple torsion test2505.6Method 6: WireWrapping testMETHOD1 SCOPEThis Standard specifies methods for single and reverse bend testing of coated and uncoated metal sheet, strip and plate.NOTES:1Criteria for assessment of the result are not included; such requirements are within the province of the product Standard, or determined by agreement between the purchaser and the supplier.2Where angles of bend of test pieces are specified in product Standards, they are considered to be minimum angles. However, where radii of bends of mandrels or formers are specified, they are considered to be maximum radii.2 DEFINITIONSFor the purpose of this Standard, the following definitions apply:2.1 Longitudinal bend testA test in which the length of the test piece is parallel to, and the axis of the bend at right- angles to, the principal direction of rolling (see Figure 1).Accessed by UNIVERSITY OF SOUTH AUSTRALIA on 27 Feb 2007AS 2505.12004 22.2 Reverse bend testA test in which a test piece is deformed by bending repeatedly through 90 degrees, in opposite directions over a specified radius.NOTE: One complete reverse bend consists of bending the test piece through 90 degrees and returning the test piece to its original position. Two complete reverse bends consists in bending the test piece at the completion of one reverse bend in the opposite direction through 90 degrees and returning the test piece to its original position (see Figure 2).2.3 Simple bend testA test in which a test piece is deformed by bending through a specified angle without reversing the direction of flexure.2.4 Test pieceA piece taken from a test specimen and suitably prepared for testing.2.5 Test sampleA portion of metal or product, or a group of items selected from a batch or group by a sampling procedure.2.6 Test specimenA portion or a single item taken from a test sample for the purpose of applying a particular test.2.7 Transverse bend testA test in which the length of the test piece is at right-angles to, and the axis of bend parallel to, the principal direction of rolling (see Figure 3).3 NOTATIONFor the purpose of this Standard, the following symbols and designations apply:a = thickness of test piece*, in millimetres b = width of flat test piece, in millimetres d = diameter of mandrel, in millimetresh = distance from top of supports to bottom face of guides, in millimetresl = length of test piece, in millimetresnb = number of reverse bendsr = nominal internal radius of test piece after bending, in millimetresr = radius of supports, in millimetres = angle of bend, in degrees4 TEST APPLIANCESTest appliances shall be of such construction that test pieces can be appropriately controlled during the performance of the test and be of adequate design, manufacture and materials to ensure reproducibility of results.All support surfaces and mandrels shall be wider than the test piece.* Except where test pieces are machined, a will be the original metal thickness t. Standards Australia.au3 AS 2505.120045 TEMPERATURE OF TEST PIECESThe temperature of test pieces at the beginning of a test shall be room temperature which, unless otherwise specified in the product Standard, shall be between 10°C and 35°C.In the event of dispute, the temperature of test pieces at the beginning of a test shall be23 ±5°C.6 SELECTION AND PREPARATION OF TEST PIECE6.1 GeneralTest samples shall be selected and prepared for testing as specified in the product Standard.NOTE: Other methods of selection and preparation may be agreed between the purchaser and supplier.If other methods of selection and preparation are not specified or agreed, the appropriate clauses of this Standard shall apply.6.2 Selection of test pieceIf the position of the test piece in relation to the original sheet, strip and plate from which it was taken is known, the test piece shall be prepared with its centre as near as practicable to the one-quarter width position (see Figure 4)NOTE: Arrow indicates principal direction of rolling.FIGURE 1 LONGITUDINAL BEND TEST Standards Australia.auPosition of test piece at completion of tw o reverse bends Position of test piece at completion of one reve rse bend Accessed by UNIVERSITY OF SOUTH AUSTRALIA on 27 Feb 2007Star tposition FIGURE 2 METHOD OF COUNTING REVERSE BENDSAS 2505.12004 4NOTE: Arrow indicates principal direction of rolling.FIGURE 3 TRANSVERSE BEND TESTPr incipal direction of rolling Standards Australia.auTr ansverse bend test piece 1/4 widthMid-width position 1/4 width Longitudinal bend test piece Accessed by UNIVERSITY OF SOUTH AUSTRALIA on 27 Feb 2007FIGURE 4 POSITION OF TEST PIECE6.3 Preparation of test pieceTest pieces may be stamped, sheared, sawn, flame-cut or machined and if necessary straightened, provided that any distortion or heating does not significantly affect the test result. There shall be no burrs, scratches or marks which can adversely affect the result. Unless otherwise specified in the product Standard, edges may be rounded to a radius as follows:(a) For thicknesses up to 10 mm . not greater than 1.0 mm. (b)For thicknesses above 10 mm . 0.1 times the thickness but not greater than 3 mm. Slight curvature of the test piece is acceptable.If the test piece is produced by machining a single surface of the product (seeClause 6.4.2(c), the test shall be carried out with the unmachined surface in tension.In a reverse bend test the unmachined side shall be in tension in the first bend of the test.In the event of dispute, any effect produced by the method of preparation on the metal structure along a cut edge shall be removed by longitudinal milling, planing or grinding, unless otherwise specified in the product Standard.6.4 Dimensions6.4.1 Length of test piecesThe length of test piece shall be suitable for the test method selected.Accessed by UNIVERSITY OF SOUTH AUSTRALIA on 27 Feb 20075 AS 2505.120046.4.2 Width of test piecesTest pieces shall have the following widths, as appropriate to the thickness of the product being tested:(a) Product thickness less than 3.0 mmFor product thickness less than 3.0 mm, test pieces shall be of rectangular cross- section and of full product thickness.The width of the test pieces shall be not less than 20 mm or the full product width if less than 20 mm wide.(b) Product thickness 3.0 mm up to and including 25 mmFor product thickness 3.0 mm up to and including 25 mm, test pieces shall be of rectangular cross-section and of full product thickness.The width of the test pieces shall be not less than 30 mm or the full product width if less than 30 mm wide.(c) Product thickness above 25 mmUnless otherwise specified in the product Standard, test pieces for product thickness above 25 mm may be machined to a thickness of not less than 25 mm but shall be not less than 30 mm wide. Machining shall be restricted to one surface only.7 TEST PROCEDURES7.1 Simple bend test7.1.1 ApplicationThe method is suitable for bending metal of all thicknesses through angles up to a nominal180 degrees.7.1.2 ProcedureThe simple bend test shall be carried out as follows:(a) Place the test piece on two parallel supports; the radius R of the supports shall be not less than 10 mm.The distance between supports for a nominal 180-degree bend shall be equal to(D + 3a) ±a/2 (see Figure 5).(b) Apply force through the mandrel at a point midway between the supports.The diameter of the mandrel shall be as specified in the product Standard.(c) Increase the force slowly until the test piece is bent through the specified angle while the force is still applied.(d) Remove the force and examine the external bent portion of the test piece for cracks, or as required by the product Standard.NOTE: Small cracks at the edges of rectangular test pieces and cracks which require magnification to be visible may be disregarded, unless the product Standard indicates otherwise.7.2 Vee-block bend test7.2.1 ApplicationThe method is suitable for bending sheet and strip metals through angles up to a nominal90 degrees. Standards Australia.auAS 2505.12004 67.2.2 ProcedureThe Vee-block bend test shall be carried out as follows:(a) Lay the test piece across a Vee-block which has an included angle as specified in the product Standard.(b) Apply a force through a mandrel at the midpoint of the Vee-block until the test piece is just stopped by the block (see Figure 7).The diameter of the mandrel shall be as specified in the product Standard.(c) Remove the force and examine the external bent portion of the test piece for cracks, or as required by the product Standard.NOTE: Small cracks at the edges of rectangular test pieces and cracks which require magnification to be visible may be disregarded, unless the product Standard indicates otherwise.FMandrel Standards Australia.auTest piece aD /2 aR 10 mm min. Suppor t( D + 3 a ) a /2 Suppor tNOTE: Roller supports may be used (see Figure 6) when the distance between the supports is within the limits of(D + 3a) ± a/2 (see Clause 7.1.2(a).FIGURE 5 SIMPLE BEND TESTFTest piece Mandrel aRoller suppor tD /2 Roller suppor tAccessed by UNIVERSITY OF SOUTH AUSTRALIA on 27 Feb 2007R 10 mm min. a ( D + 3 a ) a /2 FIGURE 6 MODIFICATION OF SIMPLE BEND TEST USING ROLLER SUPPORTS7 AS 2505.12004F Standards Australia.auTest piece Mandrel aD /2 R 10 mm min. Accessed by UNIVERSITY OF SOUTH AUSTRALIA on 27 Feb 2007a FIGURE 7 VEE-BLOCK BEND TEST7.3 Supported mandrel bend test7.3.1 ApplicationThe method is suitable for bending sheet and strip metals of all thicknesses through angles up to a nominal 180 degrees (see Figures 8 and 9).A limitation may arise in the testing of thin metal where a specified radius of the mandrel is less than that which would allow the roller pivot mechanism to be constructed within the mandrel. In such cases use an external pivot design.7.3.2 ProcedureThe supported mandrel bend test shall be carried out as follows:(a) Clamp one end of the test piece and the mandrel in a suitable vice.The size and shape of the mandrel shall be as specified in the product Standard.(b) Apply a force to the end of the test piece and at right-angles so as to bend the test piece around the mandrel.The force may be applied manually or by blows from a soft mallet or by use of a roller bending device. Where a roller bending device is used, the distance from the point of contact of the roller to the mandrel shall not exceed 2a (see Figure 9).(c) Remove the test piece and examine the external bent portion for cracks, or as required by the product Standard.NOTE: Small cracks at the edges of rectangular test pieces and cracks which require magnification to be visible may be disregarded, unless the product Standard indicates otherwise.7.4 Pressure bend test7.4.1 ApplicationThe method is suitable for bending sheet and strip metals of all thicknesses through angles of bend varying from nominal angles of 90 degrees to 180 degrees.7.4.2 ProcedureThe pressure bend test shall be carried out as follows:(a) Take a test piece and bend through an angle of 90 degrees by one of the preceding methods described in this Standard.The diameter of the mandrel used shall be as specified in the product Standard.Accessed by UNIVERSITY OF SOUTH AUSTRALIA on 27 Feb 2007AS 2505.12004 8(b) Apply a compressive force until one of the following conditions as specified in the product Standard is attained:(i) To a specified angle (see Figure 10(a).(ii) The arms of the test piece are parallel to each other at a given distance apart(see Figure 10(b) and (c).(iii) The thickness of the spacer shall be as specified in the product Standard.(iv)The arms of the test piece are in direct contact with each other (seeFigure 10(d).(c) Remove the test piece and examine the external bend portion for cracks, or as required by the product Standard.NOTE: Small cracks at the edges of rectangular test pieces and cracks which require magnification to be visible may be disregarded, unless the product Standard indicates otherwise.7.5 Reverse bend test7.5.1 ApplicationThe method is suitable for the testing of sheet and strip metal up to about 3 mm thick.7.5.2 ProcedureThe reverse bend test shall be carried out as follows:(a) Select appropriate supports having a radius as specified in the product Standard. (b)Insert the test piece in the bend test apparatus and clamp tightly (see Figure 11).NOTE: Tensile pre-stressing of the test piece to ensure close contact with the supports ispermitted, when specified in the