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This standard is developed in accordance with the rules given in GB/T 1.1-2009.
This standard was proposed by the China Nonferrous Metals Industry Association.
This standard is under the jurisdiction of National Technical Committee on Nonferrous. Metals of Standardization Administration of China (SAC/TC 243)
Methods for evaluating the weld quality of seam welds in aluminium and aluminium alloy extrusion
1 Scope
This standard specifies the room temperature inspection method for the weld quality of weld seam in aluminium and aluminium alloy extrusion.
This standard is applicable to the inspection of the weld quality of weld seam in aluminium and aluminium alloy extrusion (hereinafter referred to as "weld quality").
2 Normative references
The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.
GB/T 3246.2 Inspection method for structure of wrought aluminum and aluminum alloy products—Part 2: Inspection method for microstructure
GB/T 16865 Test pieces for tensile test for wrought aluminum and magnesium alloy products
3 Etching method
The test shall be conducted in accordance with those specified in GB/T 3246.2.
4 Fracture method
4.1 Method summery
The fracture test is carried out by applying force to the specimen weld seam in extrusion, which causes obvious bending deformation or fracture to the specimen. The weld quality of the weld seam in extrusion is judged according to whether the weld seam in extrusion is broken or the fracture conditions. This method is applicable to specimens in artificial aging state.
4.2 Test device
4.2.1 Test machine: hydraulic or mechanical pressure tester or universal material test machine.
4.2.2 For a fracture test device equipped with support and pressure head (as shown in Figure 1), the hardness of support and pressure head is not less than HRC45, the shape of pressure head is shown in Figure 1 (choose one from the figures), and the arc diameter D of the pressure head is not more than 8mm.
a) The weld seam in extrusion is basically perpendicular to the profile surface b) The weld seam in extrusion is obviously not perpendicular to the profile surface
Keys:
1——pressure head;
2——weld seam;
3——specimen;
4——support;
D——pressure head diameter;
a——specimen thickness;
l——support span.
Figure 1 Schematic diagram of specimen and fracture fixture
4.3 Specimen preparation
4.3.1 Cut macrostructure specimens according to GB/T 3246.2. If the specimens are acceptable in macrostructure inspection, determine the weld seam position and mark it.
4.3.2 Cut the specimen at the weld seam in extrusion of profile and ensure that the weld seam is located in the middle of the specimen.
4.4 Test procedure
4.4.1 Mount the fixture on the test machine and ensure the coaxiality.
4.4.2 Adjust the support span, which shall be determined using Equation (1):
(1)
where,
D——the pressure head diameter, mm;
a——the specimen thickness, mm;
l——the support span, mm;
4.4.3 Mount the specimen on the fixture. When the weld seam is basically perpendicular to the profile surface, the weld seam of the specimen shall be located on the axis of the fixture [as shown in Figure 1a)]. When the weld seam is obviously not perpendicular to the profile surface, the weld seam in extrusion on the bending surface of the specimen shall be located on the axis of the fixture [as shown in Figure 1b)]. If there is any special requirement, the position for force application shall be determined through negotiation between the supplier and the purchaser.
4.4.4 The fracture test shall be carried out at a test speed not less than 10 mm/min until the bending angle of the specimen reaches 180° or the specimen breaks.
4.5 Result evaluation
4.5.1 If the weld seam is not broken, the weld quality is judged as acceptable.
4.5.2 If the fracture surface of the weld seam is fibrous (see Figure 2 for fibrous fracture conditions), the weld quality is judged as acceptable.
4.5.3 If the edge of the weld seam fracture is in the shape of shear lip (see Figure 2 for the shear-lip-shaped conditions), or the fracture forms an angle of about 45° with the surface of the specimen, the weld quality is judged as acceptable.
4.5.4 If the weld seam fracture is shown as smooth and straight (see Figure 2 for smooth and straight fracture conditions), the weld quality is judged as rejectable.
4.5.5 If the weld seam fracture conditions are characterized by the coexistence appearance of smooth, straight fracture and fibrous fracture and/or shear-lip-shaped fracture (as shown in Figure 2), the weld quality is judged as rejectable.
