2. Application 2.1 Selection of a test specimen of appropriate dimensions will allow measurement of chilling tendencies of all gray iron
compositions, with the exception of those having silicon contents much over 2.50 % together with carbon contents over 3.50 %.
3. Test Specimens 3.1 The patterns for the test specimens shall be made of metal to the dimensions shown in Fig. 1. With the exception of the length of the test specimen, dimensions shall not vary more than 61⁄32 in. (0.8 mm). The tolerance on the length of the specimen shall be 61⁄8 in. (3.2 mm). The radius on the apex of the wedge should be formed by filing a 1⁄32-in. flat on the sharp edge of the metal pattern and then carefully rounding the edges formed by the 1⁄32-in. flat and the sides of the wedge. If draft on the pattern is desired, it may be obtained by varying dimension H (Fig. 1) from one end of the specimen to the other. The pattern should be mounted in a core box so that the final core can be poured with the wedge in such a position that its length is vertical.There shall be 1-in. (25.4-mm) minimum sand at the bottom of the core.
4. Procedure 4.1 Cores—Make the test in a core. The cores may be either single cores or gang cores. If a gang core is used, the minimum amount of sand between adjacent test specimens shall be not less than 21⁄2 × B (Fig. 1). The sand cores shall be well cured and free of moisture. The base sand shall be of such fineness that a smooth casting will be obtained. A sand with an AFS fineness2 of about 70 will be found satisfactory, although a sand with a fineness of 100 or finer may be used for the smaller test specimens. 4.2 Pouring Practice—Pour all samples at as consistent a pouring temperature as possible since the amount of chill is clearly affected by the pouring temperature. Take precautions to obtain a representative sample of iron for the test specimen. Best results are obtained with a sample ladle lined with a refractory mixture that is free of graphite and chilled iron. The ladle should hold at least 5 lb (2.3 kg) of iron in order to avoid excessive chilling of the iron before the test specimen can be poured. Filling the ladle once with iron just prior to obtaining the sample for test is recommended.1 These test methods are under the jurisdiction ofASTM Committee A04 on Iron Castings and are the direct responsibility of Subcommittee A04.21 on Testing. Current edition approved July 1, 2011. Published July 2011. Originally approved in 1953. Last previous edition approved in 2005 as A367 – 60 (2005). DOI: 10.1520/A0367-11.