ISO 148-2:2016 pdf free
ISO 148-2:2016 pdf free.Metallic materials一Charpy pendulum impact test
One method of verifying this is to use a test piece having dimensions of 55 mm × 10 mm × 10 mm that is tightly wrapped in thin paper e.g. by means of adhesive tape) and a striking edge that is tightly wrapped in carbon paper with the carbon side outermost (i.e. not facing the striker). From its position of equilibrium, the pendulum is raised a few degrees, released so that it contacts the test piece, and prevented from contacting the test piece a second time. The mark made by the carbon paper on the paper covering the test piece should extend completely across the paper. This verification can be performed concurrently with that of checking the angle of contact between the striker and the test piece (see 6.4.8).
Hammers are often of one of two basic designs (see Figure 1). When using the C-type hammer, the broken test pieces will not rebound into the hammer if the clearance at each end of the test piece is greater than 13 mm. If end stops are used to position test pieces, they shall be retracted prior to the instant of impact. When using the U-type hammer, means shall be provided to prevent the broken test pieces from rebounding into the hammer. In most machines using U-type hammers, shrouds (see Figure 3) should be designed and installed with the following requirements:
a) a thickness of approximately 1,5 mm;
b) a minimum hardness of 45 HRC;
c) a radius of at least 1,5 mm at the underside corners;
d) a position in which the clearance between them and the hammer overhang does not exceed 1,5 mm.
In machines where the opening within the hammer permits a clearance between the ends of the test piece (resting in position ready to test) and the shrouds of at least 13 mm, the requirements of a) and d) need not apply.ISO 148-2 pdf download.
