BS ISO 20064:2019 pdf free
BS ISO 20064:2019 pdf free.Metallic materials – Steel – Method of test for the determination of brittle crack arrest toughness, Kca
The standard test piece configuration is shown in Figure 5. Table 2 shows the ranges of test piece thicknesses, widths and width-to-thickness ratios[11][12][15].The test piece length shall be equal to or greater than 500 mm or W, whichever is greater.A crack starter notch shall be introduced at a test piece edge. The notch may be a mechanical or pressed notch. The pressed notch can be formed by placing a jig having a sharp edge on the bottom of the mechanical notch and applying hydraulic pressure to the jig. The length of the notch shall be 29 mm. No other requirements are specified for the notch shape, but the notch edge shape shall be designed so that a brittle crack is initiated by impact within the impact energy value specified in 9.2 but does not initiate during force increase before attaining a specified force value. Figure 6 shows the recommended notch configurations. Side-grooves at the notch-root may be machined on both faces of the test piece to minimize crack deviation and branching. However, the side-groove depth shall be equal to or less than 0,1B and the side-groove length measured from the notch-root shall be equal to or less than B or 0,1W,whichever is smaller. A notch of the same length shall be introduced at the opposite edge to avoid bending moment by matching the net-section centre with the loading axis. In case the side-grooves are applied,however, the notch length at the opposite edge shall be determined so that there is no bending moment.
As shown in Figure 9 a), the flatness (angular distortion, linear misalignment) of the weld between a test piece and an extension plate shall be 4 mm or less per 1 m. However, when preloading is applied,welding residual stress and distortion can be reduced. In this case, flatness may be measured after the preloading. The force of the preloading shall be equal to or less than 95 % the applied force specified in 8.1. As shown in Figure 9 b), the accuracy of the in-plane loading axis shall be 0,5 % of the distance between the pins or less, and the accuracy of the out-of-plane loading axis shall be 0,4 % of the distance between the pins or less.BS ISO 20064 pdf free.