Section 9 Consumables for welding aluminium alloys

9.1.1 Tests for the approval of consumables intended for welding the aluminium alloys detailed in Ch 8 Aluminium Alloys are to be carried out generally in accordance with the requirements of Ch 11, 1 General, Ch 11, 2 Mechanical testing procedures and Ch 11, 5 Wires and wire-gas combinations for manual, semi-automatic and automatic welding, except as otherwise detailed in this Section.

9.1.2 Approval will be indicated by the grade shown in Table 11.9.1 Requirements for butt weld tests. Plate of the corresponding type of aluminium alloy and of appropriate thickness is to be used for the preparation of the weld test assemblies, and may be of any temper listed in LR Rules.

Table 11.9.1 Requirements for butt weld tests

Consumable Approval Grade (see Note 1)	Base material used for the test	Tensile strength N/mm2 minimum	Bend test ratio
LR RA/LR WA	5754	190	3
LR RB/LR WB	5086	240	6
LR RC1/LR WC1	5083	275	6
LR RC2/LR WC2 (see Note 2)	5383 or 5456	290	6
LR RC3/LR WC3 (see Note 2)	5059	330	6
LR RD/LR WD (see Note 4)	6005A	170	6
	6061	170	6
	6082	170	6
Note 1. The prefixes ‘R’ and ‘W’ indicate ‘rod’ form (for Gas Tungsten Arc Welding (GTAW)) or ‘wire’ form (for Gas Metal Arc Welding (GMAW) and GTAW).
Note 2. Approval of grade LR RC2/LR WC2 confers approval of 5383, 5456 and 5083 base material grade.
Note 3. Approval of grade LR RC3/LR WC3 confers approval of 5059, 5383, 5456 and 5083 base material grades.
Note 4. Approval of grade LR RD/LR WD confers approval of 6005A, 6061 and 6082 base material grades.

9.1.3 The welding technique will be indicated in the approval grading by a letter:

9.1.4 The compositions of the shielding gas and the filler/electrode wire are to be reported.

9.1.5 Approval granted using the multi-run technique for a specific filler/electrode wire with a gas in one of the groups listed in Table 11.9.2 Shielding gas compositions will extend to any other gas compositions within that same group, provided that the gas composition is within the range recommended by the consumable manufacturer, subject to agreement with LR.

9.1.6 Approval granted for the two-run technique will be for a specific shielding gas composition; additional tests may be required if a change in shielding gas composition is sought.

9.1.7 On completion of welding, assemblies are to be allowed to cool naturally to ambient temperature. Welded test assemblies and test specimens are not to be subjected to any heat treatment after welding except for the alloy Grades 6005A, 6061 and 6082. These are to be allowed to naturally age at ambient temperature for a period of 72 hours from the completion of welding, before testing is carried out. A second solution heat treatment is not permitted.

9.1.8 All butt test assemblies are to be subjected to both radiographic and visual examination and imperfections such as lack of fusion, lack of penetration, cavities, inclusions, pores and cracks assessed in accordance with Intermediate Level C of ISO 10042, aided where necessary by dye penetrant and ultrasonic examination.

9.1.9 Fillet weld test assemblies and macro-sections are to be visually examined for imperfections, such as lack of fusion, lack of penetration, cavities, inclusions, pores and cracks, in accordance with Intermediate Level C of ISO 10042, aided where necessary by radiographic and dye penetrant examination.

9.2.1 Plate of the corresponding type of aluminium alloy and of appropriate thickness is to be used for the preparation of the weld test assemblies.

9.2.2 The welding parameters are to be within the range recommended by the manufacturer and are to be reported.

9.2.3 Welded assemblies are to be prepared and tested in accordance with Ch 11, 9.3 Deposited metal test assembly, Ch 11, 9.4 Butt weld test assemblies and Ch 11, 9.5 Fillet weld test assembly.

9.3.1 One assembly is to be prepared in the downhand position as shown in Figure 11.9.1 Deposited metal test assembly.

Figure 11.9.1 Deposited metal test assembly

9.3.2 The chemical composition of the plate used for the assembly is to be compatible with the weld metal.

9.3.3 The thickness of the plate used, and the length of the assembly, are to be appropriate to the welding process. The plate thickness is to be not less than 12 mm.

9.3.4 For the approval of filler wire/gas and electrode wire/gas combinations for manual or semi-automatic welding by GTAW or GMAW, one test assembly is to be welded using any size of wire within the range for which approval is sought.

9.3.5 For automatic multi-run approval, one test assembly is to be welded by the respective process using the recommended diameter of wire.

9.3.6 The weld metal is to be deposited in multi-run layers in accordance with normal practice. The direction of deposition of each layer is to alternate from each end of the plate.

9.3.7 The deposited weld metal in the assembly is to be analysed and reported including the contents of all significant elements. The elements reported will be dependent on the type of aluminium alloy for which approval of the consumables is requested. The results of the analysis are not to exceed the limit values specified in the standards or by the manufacturer, the narrower tolerances being applicable in each case.

9.4.1 Plate of the corresponding type of aluminium alloy and of an appropriate thickness is to be used for the preparation of the test assemblies.

9.4.2 In order to ensure sound and representative welds, it is essential that test assemblies are cleaned and degreased prior to welding. Assemblies as shown in Figure 11.9.2 Butt weld test assembly (positional, multi-run technique) are to be prepared for each welding position (downhand, horizontal-vertical, vertical-upward, vertical-downward, and overhead) for which the consumable is recommended by the manufacturer; except that consumables satisfying the requirements for downhand and vertical-upward positions will be considered as also complying with the requirements for the horizontal-vertical position. Any wire diameter(s) to be approved may be used.

Figure 11.9.2 Butt weld test assembly (positional, multi-run technique)

9.4.3 One assembly, as shown in Figure 11.9.3 Butt weld test assembly (downhand, multi-run technique), is to be prepared for welding in the downhand position. The assembly is to be welded using, for the first run, wire of the smallest diameter recommended by the manufacturer and, for the remaining runs, wire of the largest diameter to be approved.

Figure 11.9.3 Butt weld test assembly (downhand, multi-run technique)

9.4.4 The welding conditions are to be in accordance with the recommendations of the manufacturer and are to be reported in detail.

9.4.5 The welded assemblies are to be subjected to NDE. Imperfections are to be assessed in accordance with Ch 11, 9.1 General 9.1.8.

9.4.6 The test specimens are to be taken from the welded assemblies as shown in Figure 11.9.2 Butt weld test assembly (positional, multi-run technique) and Figure 11.9.3 Butt weld test assembly (downhand, multi-run technique). For each assembly they are to comprise:

• 2 transverse tensile specimens;
• 2 face bend specimens; and
• 2 root bend specimens.

9.4.7 All tensile test specimens are to have a tensile strength not less than the respective value shown in Table 11.9.1 Requirements for butt weld tests. The position of each fracture is to be reported.

9.4.8 The bend test specimens are to be bent around a former having a diameter not more than the number of times the thickness of the test specimen, as shown in Table 11.9.1 Requirements for butt weld tests, and can be considered as complying with the requirements if, after bending to an angle of not less than 180°, no crack or other open defect exceeding 3 mm in length can be seen on the outer surface. Flaws appearing at the corners of a test specimen may be ignored.

9.4.9 In order to obtain uniform bending of the bend test specimens, it is recommended that the wrap-around or guided bend test using a roller method is employed.

9.5.1 When approval is being sought for both butt and fillet welding, one assembly is to be prepared and welded in the horizontal-vertical position and tested in accordance with the appropriate requirements of Ch 11, 3.5 Fillet weld test assemblies, except that the plates are to be of an aluminium alloy compatible with the weld metal, that no hardness tests are required and that for automatic multi-run approval only one fillet weld bead is to be made using the recommended wire diameter. In this case, the bead size is to be as large as the maximum single bead size recommended by the manufacturer for fillet welding.

9.5.2 When approval is being sought for fillet welding only, one assembly is to be prepared and welded in each position for which approval is sought, and tested as detailed in Ch 11, 9.5 Fillet weld test assembly 9.5.1.

9.5.3 The results of examination of the macro-specimens and the fractured fillet welds are to be reported in accordance with Ch 11, 3.5 Fillet weld test assemblies 3.5.4 and Ch 11, 3.5 Fillet weld test assemblies 3.5.6. Imperfections are to be assessed in accordance with Ch 11, 9.1 General 9.1.9.

9.6.1 Two butt weld test assemblies are to be prepared using the following plate thicknesses:

1. one with the maximum thickness for which approval is requested,

2. one with a thickness approximately one half to two thirds that of the maximum thickness.

9.7.1 The plates used are to be of the aluminium alloy appropriate to the approval required as shown in Table 11.9.1 Requirements for butt weld tests. The composition of the plate material is to be within the range specified for that alloy in Table 8.1.2 Chemical composition, percentage in Ch 8 Aluminium Alloys and is to be reported including all significant elements.

9.7.2 The wire diameter, edge preparation, welding current, arc voltage and travel speed are to be in accordance with the manufacturer's recommendations and are to be reported.

9.7.3 Each butt weld is to be made in two runs, one from each side. After completion of the first run the assembly is to be left in still air until it has cooled to less than 50°C.

9.7.4 The welded assemblies are to be subjected to NDE. Imperfections are to be assessed in accordance with Ch 11, 9.1 General 9.1.8.

9.7.5 The test specimens as shown in Figure 11.9.4 Butt weld test assembly (two-run technique) are to be prepared from each test assembly. The edges of the discards are to be polished and etched, and must show complete fusion and inter-run penetration of the welds. Each cut in the assembly is also to be examined to confirm that complete fusion and penetration have been achieved.

Figure 11.9.4 Butt weld test assembly (two-run technique)

9.7.6 The results of the transverse tensile tests are to be as in Ch 11, 9.4 Butt weld test assemblies 9.4.7 and of the bend tests as in Ch 11, 9.4 Butt weld test assemblies 9.4.8. The position of the fracture in each transverse tensile specimen is to be reported.

9.8.1 Annual tests are to consist of the following:

1. for combinations approved for the multi-run technique, one deposited metal assembly in accordance with Ch 11, 9.3 Deposited metal test assembly and one downhand butt assembly in accordance with Ch 11, 9.4 Butt weld test assemblies Figure 11.9.2 Butt weld test assembly (positional, multi-run technique);

2. for combinations approved for the two-run technique, one butt weld assembly in accordance with Ch 11, 9.7 Butt weld test assemblies (two-run technique) using plate material of thickness equal to one half to two thirds that of the maximum thickness approved.