AS 1330:2019 pdf download.Metallic materials —— Drop weight tear test for steels.
5 Apparatus
5.1 Testing machine
The testing machine may be a falling weight type or a pendulum type. Other types of testing machine, e.g. with hydraulic actuators, may be used providing it can be demonstrated that their impact velocity and dynamic performance conform to the requirements of Clause 5.3.
5.2 Anticipated fracture
The energy available at impact shall be greater than the anticipated fracture absorption energy of the test piece.
NOTE 1 To ensure regular crack propagation, an available energy of 1.5 times the absorbed energy is generally sufficient. If the absorbed energy is not measured, the minimum required impact energy may be estimated from the Charpy V-notch energy adjusted for the test piece cross-sectional fracture area.
NOTE 2 As a guide to the design of the equipment, it has been found that approximately 2800 J is required to completely fracture a steel test piece of up to 13 mm thickness with a tensile strength of up to 700 MPa.
5.3 Test machine setup
This test involves fracturing a test piece containing a pressed notch by supporting it near its ends and impacting it behind the notch; see Figure 1.
The path of the striker shall be normal to the longitudinal axis of the test piece and the velocity of the striker at impact shall be not less than 5 rn/s and not more than 10 rn/s. The supports shall be hardened steel cylindrical surfaces of radius 15 mm ± 5 mm. The distance between the axes of the supports shall be parallel and coplanar and be 254 mm ± 1.5 mm. Provision shall be made for locating the root of the notch of the test piece within 1.5 mm of a plane which is normal to the axis of the test piece and midway between the axes of the supports. When the striker is in contact with the test piece, the line of contact shall extend over the full thickness of the test piece and be opposite the root of the notch and within ±1.5 mm. Provision shall be made to prevent out of plane rotation of the test piece on or after impact. NOTE It has been found that the most consistent results are obtained when using test machines with anvil support radii of 15 mm ± 1 mm and hammer radius of 25 mm ± 1 mm as jamming and friction are minimized under these conditions.
5.4 Tolerances
The tolerances on the machine and set-up dimensions shall be in accordance with Table 1.
5.5 Temperature control
A temperature-controlled environment shall be provided in which the test piece is soaked for temperature conditioning before testing. Provision shall be made for circulation of the medium to ensure a uniform soaking temperature, see Clausel.1. NOTE A procedure should be developed for test temperatures above or below room temperature, to ensure temperature change between the exit from the temperature conditioning medium and the execution of the test is within the specified limits, see Clause 7.2.
6 Test piece
6.1 Location of the test piece
A test specimen shall be removed from a pipe so that the length of the specimen is in the circumferential direction of the pipe and in the approximate position shown in Figure 2. NOTE For pipes with an outside diameter larger than 500 mm, the alternative position b may be used. For plate and strip material, a test piece shall be selected to approximate its final position in the pipe.
6.2 Test piece geometry
The central 50 mm portion, L (see Figure 1), should be left with the original pipe curvature. The material each side of the undeformed 50mm area is bent such that the mid thickness at the centre of the test piece shall be in the same plane as the mid thickness at the anvil supports. This is known as a gull-wing test piece. NOTE 1 A detailed description for forming a gull-wing test piece is given in Appendix C.AS 1330 pdf download.