GL test method

II-Part3 GL2000Section5Mechanical and Technological Tests Chapter2Page5–1 BSection5Mechanical and Technological TestsPreliminary remarks:This section has,for the time being,still been retained in its earlier form despite the fact that more up-to-date EN and ISO standards have since been either issued or are available in draft form relating to the key de-structive tests carried out on welded joints in metallic materials.The intention is to delete this section alto-gether at a later date and instead to make reference only to the new standards in Chapter1,Section4, "Welding Procedure Tests"(where the information relating to the mechanical and technological tests is chiefly needed).These standards include:–EN895/ISO4136Transverse tensile test(replacement for DIN50120-1and50120-2)–EN876/ISO5178Longitudinal tensile testing of the weld metal infusion welded joints–EN910/(ISO5173)Bend tests(replacement for DIN50121-1and50121-2)–EN875/ISO9016Notched bar impact test(replacmenet forDIN50122)–EN1043/ISO9015Hardness test,miscellaneous parts(Replacement for DIN50163)–EN1320/ISO9017Fracture tests(replacement for DIN50127)–EN1321Macroscopic and microscopic examinations–EN ISO8249Determination of ferrite numberThe mechanical and technological tests shall,wherever possible,be performed in accordance with the new standards.For an interim period,or where the new standards are not yet available,the mechanical and technological tests may continue to be performed in accordance with the following provisions,but also in compliance with the information given in Chapter3. The test records shall state which rules were used as a basis for the test.Where the provisions given in the various rules differ widely,the procedure shall be agreed with the Society.A.Scope1.These Rules relate to the normal methods and forms of test specimens to be used in the mechanical and technological testing of welds,e.g.of test pieces for the welding procedure and workmanship tests,as well as to the metallographic inspections necessary for this purpose.2.Special methods and forms of test specimens(e.g.for testing the manual skill of welders or testing of welding consumables,auxiliary materials and over-weldable shop primers)are specified in the relevant sections.3.The test methods and forms of specimens indicated in the standards mentioned in the following paragraphs shall be used wherever possible.Methods and forms of specimens conforming to other standards may be used by agreement with the Surveyor,pro-vided that the same results can be achieved.B.Preparation of Specimens and Testing1.All tests are to be performed by trained per-sonnel using calibrated testing machines.The testing machines must be kept in good working order by their owners and are to be calibrated at regular intervals by an independent inspecting authority.2.Before being cut out of the test piece,speci-mens are to be marked by the Surveyor.They shall then be cut out,wherever possible by a mechanical process,and machined to the required dimensions. Where specimens are cut from the test piece by a thermal process,they must be wide enough to ensure that the heat-affected zone can be completely ma-chined off.3.All mechanical and technological tests are to be performed in the presence of the Surveyor,unless otherwise stipulated or agreed.The photographs of metallographic specimens are to be submitted to him for evaluation.Chapter2 Page5–2Section5Mechanical and Technological Tests II-Part3GL2000 CC.Tensile Tests1.Tensile tests on flat tensile specimens(DIN50120,Part1)1.1This test is carried out to determine the ten-sile strength,position,type of fracture and,where appropriate,the elongation of specimens located at right angles to the seam.The flat tensile specimen shown in Fig.5.1should be used wherever possible. 1.2The thickness'a'of the specimen is normally the wall thickness.If this is greater than30mm but less than50mm,the specimens may be machined down on one side to a thickness of30mm.With thicknesses of50mm and over,two or more speci-mens regularly spaced over the section are to be pre-pared.Specimenthickness a£ 5> 5to£ 10> 10to£ 20> 20to£ 30Specimen width b Gauge length L cHead width B Total length L t Radius at shoulder r15202530Weld widthb s + 80 mm 1³ 25³ 30³ 35³ 40³ 35³ L c + 1801bs measured on the side of the weld the greaterseam width.Fig.5.1Flat tensile specimen(welded joint)1.3Welded joints in aluminium alloys shall be tested using a tensile specimen conforming to DIN50123.2.Tensile test on round tensile specimens(EN10002/DIN50125)2.1This test is carried out to determine the ten-sile strength,yield strength or0,2%proof stress,re-duction in area and elongation of the weld metal. Where necessary in the case of high-temperature steels,the0,2%proof stress at elevated temperatures shall also be established.Wherever possible,the test should be performed on a10mm diameter round ten-sile specimen of the type depicted in Fig.5.2,which is to be cut out of theweld metal with its longitudinal axis in the direction of the seam.2.2If,in exceptional cases,the weld dimensions do not permit the preparation of a10mm diameter tensile specimen,specimens with a smaller diameter may be used,provided that the gauge length is5times and the parallel length at least6times the diameter of the specimen.3.Tensile tests on cruciform tensile speci-mens3.1This test is carried out to determine the ten-sile shear strength Z S of the weld metal.Three speci-mens with the dimensions shown in Fig.5.4shall be tested in each test.GL 2000Page 5–3Fig. 5.4Cruciform tensile specimens3.2The tensile shear strength Z S is to be deter-mined by the following formula (cf. Fig. 5.5):a a tion S a a fracture tion S 12341234+=+=fracture sec sec Tensile shear strength Z S :=S BFig.D.Bend Tests1.Transverse bend test (DIN 50121, Part 1)1.1This test is carried out to determine the duc-tility of the welded joint across the seam. For this purpose the specimen is bent over a mandrel or pre-scribed diameter and the angle achieved and, if speci-fied,the bending elongation on the tension side of the specimen are measured.Specimens to Fig. 5.6 are to be prepared for the test.Section A - BDimensionsSpecimen width bSpecimen length L t 1 whereRadius r, side in tension1 If the specimen lengths L tcannot be met, the minimum specimen lengths shown in Table 6 of DIN 50 121, Part 1 apply.Specimen thickness ad __a £ 3> 27 £ 35³ 1,5 a 300430530£ 3d __a = 4d __a = 6£ 1120250250250£ 2> 11 £ 1430250250250£ 2> 14 £ 1730250250290£ 2> 17 £ 22³ 1,5 a 250290350£ 3> 22 £ 27³ 1,5 a 300350430£ 3Fig. 5.6 Specimen for transverse bend testPage5–4GL20001.2The thickness of the specimen is normally the wall thickness.If this is greater than30mm,the specimens may be machined down on one side to a thickness of30mm.On the side of the specimen which is in tension during the test,the edges may be rounded to the specified radius r.1.3Depending on the test specification,the specimens are to be mounted in the testing device in such a way that either the upper or the lower side of the weld is in tension during the test.The test rig is to be set up as shown in Fig.5.7.1.4If the bending elongation is to be deter-mined,the deformation zone on the tension side of the specimen shall be provided prior to the test with gauge marks set5mm apart and these shall be used to measure the elongation when the prescribed bending angle has been reached.The gauge length L0is the weld width plus the wall thickness.Fig.5.7Test rig1.5If the elongation behaviour of the base mate-rial and the weld metal differ greatly,e.g.in the case of welded aluminium test pieces,the test rig shown in Fig.5.8may be used in order to prevent premature incipient cracking of thespecimen.Fig.5.8Special test rig2.Side bend test(DIN50121,Part1)2.1This test is carried out to determine the duc-tility of the welded joint in the cross-sectional plane. For this purpose the specimen is bent over a mandrel of specified diameter and the bending angle attained is measured.Specimens to Fig.5.9are to be prepared for the test.2.2The specimens are to be mounted in the testing device shown in Fig.5.7in such a way that the testing load acts in the direction of the original lon-gitudinal axis of the seam.On the side in tension during the test,the long edges of the specimen may be rounded to the specified radius r.2.3If welded clad plates are to undergo side bend tests,the form of specimen shown in Fig.5.10is to be used.The dimensions are as stated in the table in Fig.5.9.Fig.5.9Specimen for side bend test(Table) Fig.5.10Form of clad side bend test specimensII - Part 3GL 2000Section 5Mechanical and Technological TestsChapter 2Page 5–5E 3.Bend test specimens from pipe joints3.1If bend test specimens are to be taken from circumferential pipe welds, the side faces must be parallel. If necessary, the side of the specimen which is in compression shall be machined in accordance with Fig. 5.11.compressionFig. 5.11 Cross section through bend test speci-men taken from a pipeE.Notched Bar Impact Tests (EN 10045/DIN 50115)1.The purpose of this test is to determine the impact energy in joules (J). ISO V-notch specimens shall be used; their location in the test piece shall be such that the longitudinal axis of the specimen is perpendicular to the direction of the seam while the notch axis is at right angles to the surface of the prod-uct (cf. Fig. 5.12). In addition, determination of the crystalline portion of the fracture surface and/or of the lateral expansion of the specimen may be agreed.Notch located at centre of weld metal (K M )Notch located in heat-affedted zone (K Ü)Cross section of specimen [mm]Mean impact energy value required EStandard specimen10 × 10Specimens of reducedsection 10 × 7,510 × 55/6 E 2/3 EEFig. 5.12Locations of specimens for notched barimpact testing2.Depending on the test specification, the notch shall be located either at the centre of the weld metal, on the fusion line or in the heat-affected zone of the base metal at a specified distance from the fusion line (cf. Fig. 5.12).3.The test is to be carried out at the specified test temperature. Where the product thickness is < 10 mm, specimens measuring 7,5 × 10 mm, 5 × 10mm and 2,5 × 10 mm should be used wherever possi-ble. For these specimens the required impact energy E (J) in relation to the standard 10 × 10 mm test speci-men shall be as indicated in the table below.4.Where specimens are taken from only one side of a double-V weld, they shall be taken from the side of the seam which was welded last.5.The specimens shall be machined down to the dimensions shown in Fig. 5.13 and compliance with the stipulated tolerances shall be verified.6.If in technically justified exceptional cases specimens with forms or locations different from those described in paras. 1 to 5 are to be used, the test requirementsshall be specially agreed with the Soci-ety.Dimensions Length WidthHeight Notch angle Height from bottom of notch Notch radiusDistance between centre of notch and ends of specimen Angle between plane of symmetry of notch and longitudinal axis of specimen Angle between adjacent longi-tudinal specimen surfacesNominal size 55 mm 10 mm 10 mm 45 °8 mm 0,25 mm 27,5 mm90 °90 °Tolerance ± 0,60 mm ± 0,11 mm ± 0,06 mm ± 2°± 0,06 mm ± 0,025 mm ± 0,42 mm± 2°± 2°Chapter2 Page5–6Section5Mechanical and Technological Tests II-Part3GL2000 GFig.5.13ISO V-notch specimenF.Hardness Testing of Welds(DIN50163,Part1)1.The hardness of welded joints shall be meas-ured by Vickers hardness tester using a load of49or 98N(HV5or HV10)on polished and etched specimens whose test face is perpendicular to the weld axis.The choice of the test load depends on the grade of material concerned.2.Normally,the test shall take the form of rows of hardness measurements,one row for fillet welds and at least two rows for butt welds,one of which is at the root and one in the area of the cover pass. Should this be insufficient for an adequate assessment of the hardness of the welded joint,a test with a fur-ther row of measurements shall be performed,e.g.in the area of the root and capping passes in the case of butt welds.The arrangement of the rows of hardness measurements shall be as shown in Fig.5.14.3.The impressions made by the hardness tester shall be close enough together to give an accurate picture of the hardness curve(cf.Fig. 5.15).The curve shall be plotted as a graph wherever possible.Fig.5.14Hardness testing with rows of hardness measurementsG.Metallographic Inspections1.The macro-and micro-structure shall be evaluated by reference to polished sections.Unless otherwise agreed,the polished face of the sections shall be perpendicular to the weld axis(see also Fig.5.14).2.The metallographic specimens shall be of such a size and ground and etched in such a way as to reveal the nature and structure of the crystallization of the weld metal and the heat-affected zone as well as the texture of the base metal and,in the case of mi-crographs,the grain boundaries in the area under examination.3.The polished sections shall be photographed and the photos appended to the inspection report. Macrographs shall normally be to a scale of1:1to 1:3;if the cross-sectional area of the weld is small, they may be magnified.For assessment of the microstructure,at least3pho-tographs shall be made of characteristic parts of the weld;these shall generally be the weld metal,the fusion line and the heat-affected zone.The magnifi-cation shall be at least100:1.II - Part 3Section 5Mechanical and Technological TestsChapter 2H Fig. 5.15Location of hardness test impressions inthe heat-affected zone–Test methods and forms of specimens –Test results2.The reports shall be submitted to the Sur-veyor in at least two copies for his perusal. He shall confirm the proper performance of the inspection and the correctness of the results by applying his stamp and signature.。