BS ISO 20064:2019 pdf free.Metallic materials – Steel – Method of test for the determination of brittle crack arrest toughness, Kca.
The force applied to an integrated test piece by the test machine shall be via a clevis pin type loading method as shown in Figure 1. Centres of the loading pins at both ends shall align with the neutral axis of the integrated test piece.5.2.5 Loading direction The test machine may be either horizontal or vertical. In the case of the horizontal direction, the test piece surfaces shall be placed either perpendicular or parallel to the ground. However, when using the parallel position, care should be taken to ensure that the temperature difference between the top and bottom surfaces of the test piece is within the values specified in 7.1.1.2. 5.2.6 Distance between the loading pins The distance between the loading pins, Lp, as defined in Figure 8, shall be 3,4W or more for preventing force drop by a reflection of stress wave at the loading pins. Since the distance between the loading pins potentially has an effect on the force drop associated with crack propagation, especially for a long arrested crack, the validity of the test results shall be verified using the method described in 9.1011]. 5.3 Impact equipment 5.3.1 Impact methods Recommended methods for applying an impact force to a wedge mounted on the notch of an integrated test piece include the drop-weight type and the air gun type, as shown in Figure 2 a) and Figure 2 b), respectively. The drop weight type method applies an impact force to the wedge by freely dropping a weight from a predetermined height. The air gun type method applies an impact force to the wedge by introducing a predetermined gas pressure into a piston-sealed cylinder, and then releasing the lock of the piston. The wedge shall be of sufficient hardness not to plastically deform during impact. The wedge thickness shall be equal to or greater than that of the test piece, and the wedge angle shall be greater than that of the notch formed in the test piece and shall have a shape capable of opening up the notch of the test piece. The recommended shape of the wedge is shown in Figure 3.BS ISO 20064 pdf download.