(6.4 to 12.7 mm) of the base of the wedge in water. The wedge may then be gradually quenched but should be removed while there is still sufficient heat in the wedge to dry off the water. If speed of testing is not important, the test specimen may be either cooled in the core or in the air. If cooled to a very dull red before quenching in water, the demarcation between the chilled iron and the gray iron is somewhat clearer than if the test specimen is quenched as soon as it is solid.
5. Measurement of Chill 5.1 Break the test specimen by striking with a hammer in such a manner that the fracture is straight and midway of its length. The chilled iron at the apex of the wedge with a few exceptions consists of two zones. That portion nearest the apex entirely free of any gray spots is designated as clear chill. That portion starting with the end of the clear chill and continuing to the location where the last spot of cementite or white iron is visible is designated as the mottled zone. The extent of the mottled zone may vary from virtually nothing to an amount equal to and even greater than the amount of the clear chill. If the wedge is measured at the junction of the gray fracture with the first appearance of chilled iron, the measurement shall be designated as total chill. In all cases, express the chill in 1⁄32 in. (0.8 mm) as measured across the wedge at the locations just described. The location of this measurement for a wedge having a narrow mottled zone is shown in Fig. 1. For structure control purposes, it is generally satisfactory to measure the wedge where the structure is approximately 50 % white iron and 50 % gray iron. This value will be found to be virtually the same as the average of the measurement of the clear chill measurement, designate the size of the test specimen. A chill reported asW3-12 would indicate that wedgeW3 was used and the width at the junction of the chilled and gray portions of the fraction was 12⁄32 in. (9.5 mm). TEST METHOD B—CHILL TEST
6. Application 6.1 This test method is better adapted than Test MethodAto irons having silicon contents of 2.50 % and over and carbon contents of 3.50 % and over. It is also useful for control purposes in high-production foundries making irons somewhat lower in carbon and silicon than indicated above. This test method is also preferable for applications in which the casting is to have a specified depth of chill.
7. Test Specimens 7.1 The patterns shall be made of metal and conform to the dimensions shown in Fig. 2. All dimensions shall be within 61⁄32 in. (0.8 mm) of those shown, with the exception of the length which may vary 6 1⁄8 in. (3.2 mm). The test specimens shown are designed to be cast in the position shown. This design is the preferred one, although for high-production work, a gang core box and pattern may be used. In this case, a test specimen with the chilled face in a vertical position may be found more convenient although it is not considered as satisfactory as the horizontally cast test specimen.
8. Procedure 8.1 Cores—Make the test in a core. For general application, a single core is considered more satisfactory than a gang core. If a gang core is used, the amount of sand between test specimens shall be 1 in. (25.4 mm) minimum or 21⁄2 × A (Fig. 2), whichever is greater. The remarks concerning cores in 4.1 apply here also. 8.2 Chill Plates—Chill plates may be cast iron, steel, copper, or graphite. Machine the surface of the chill plate. When single test specimens are cast, the chill plate shall extend at least 1 in. beyond the test specimens in all directions and shall be at least 1-in. thick. For high-production work, a sufficient number of chill plates must be available to keep the temperature of the plate below 500°F (260°C). A water-cooled steel plate will be found more satisfactory for high-production work. A water-cooled plate having a reservoir is preferable to one having circulating water. In the latter case the plate may become too cold, resulting in condensation of moisture on the plate. The chill plate must be kept free of the fire cracks and all foreign matter as the depth of chill is markedly affected by the presence of films of burned oil or other accumulations. The best practice is to clean off the plate with a wire brush as soon as the core and test specimen are removed. 8.3 Pouring Practice—Remarks on pouring practice in 4.2 apply here. In addition, do not pour iron directly on the chill plate as the depth of chill may be affected or the test specimen may burn on the chill plate. It may be desirable to place a weight on the core when pouring it as there may be a tendency for the core to lift as it is being poured.The opening in the core shall be free of sand fins and shall set flat on the chill plate. In the event the core does not fit the chill plate, rub it until it does. 8.4 Cooling of Test Piece—The remarks in 4.3 apply here. If rapid testing is desired, the chill test specimen may be quenched in water, starting with the edge farthest from the chilled edge.
9. Measurement of Chill 9.1 Break the test specimen in such a manner that the fracture is straight and follows the notch in the test specimen. The chill from the chilled face to the first appearance of a gray spot shall be designated as clear chill. The distance from the chilled face to the last appearance of a spot of white iron shall be designated as total chill. That portion of the chill affected zone between the clear chill and the total chill shall be designated as the mottled zone.As in Section 5, it will be found satisfactory for general structure and quality control purposes to measure chill from the chilled face to a location where the structure is approximately 50 % white iron, which is roughly half-way through the mottled zone. If the chill test is used for the control of iron for castings having a chilled surface for wear-resistant purposes, it would be desirable to measure and record clear chill. If the casting with a chilled surface is to have some machining operation in the proximity of the chilled surface, it may also be necessary to specify maximum depth of total chill as well as depth of clear chill. In all cases, the depth of chill shall be expressed in 1⁄32 in. (0.8 mm) and the size of the test specimen used shall be designated. For example, a
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Copyright by ASTM Int'l (all rights reserved); Mon Aug 17 02:28:35 EDT 2015 Downloaded/printed by Suranaree University of Technology (Suranaree University of Technology) pursuant to License Agreement. No further reproductions authorized.
measurement recorded as 4C-12 indicates that test specimen design 4C was used and the depth of chill was 12⁄32 in. (9.5 mm).
(6.4-12.7 mm) ฐานของลิ่มในน้ำ ลิ่มอาจแล้วจะค่อย ๆ quenched แต่ควรเอาออกขณะที่มีความร้อนเพียงพอยังคงในลิ่มให้แห้งน้ำ ถ้าความเร็วของการทดสอบไม่มีความสำคัญ ตัวอย่างทดสอบอาจจะอาจจะระบายความร้อนด้วยหลัก หรือ ในอากาศ ถ้าระบายความร้อนด้วยการแดงซบก่อนการชุบในน้ำ แบ่งระหว่างเตารีดเย็นและเหล็กสีเทาได้ค่อนข้างชัดเจนกว่าถ้าตัวอย่างทดสอบ quenched ทันทีที่เป็นของแข็ง5. Measurement of Chill 5.1 Break the test specimen by striking with a hammer in such a manner that the fracture is straight and midway of its length. The chilled iron at the apex of the wedge with a few exceptions consists of two zones. That portion nearest the apex entirely free of any gray spots is designated as clear chill. That portion starting with the end of the clear chill and continuing to the location where the last spot of cementite or white iron is visible is designated as the mottled zone. The extent of the mottled zone may vary from virtually nothing to an amount equal to and even greater than the amount of the clear chill. If the wedge is measured at the junction of the gray fracture with the first appearance of chilled iron, the measurement shall be designated as total chill. In all cases, express the chill in 1⁄32 in. (0.8 mm) as measured across the wedge at the locations just described. The location of this measurement for a wedge having a narrow mottled zone is shown in Fig. 1. For structure control purposes, it is generally satisfactory to measure the wedge where the structure is approximately 50 % white iron and 50 % gray iron. This value will be found to be virtually the same as the average of the measurement of the clear chill measurement, designate the size of the test specimen. A chill reported asW3-12 would indicate that wedgeW3 was used and the width at the junction of the chilled and gray portions of the fraction was 12⁄32 in. (9.5 mm). TEST METHOD B—CHILL TEST6. Application 6.1 This test method is better adapted than Test MethodAto irons having silicon contents of 2.50 % and over and carbon contents of 3.50 % and over. It is also useful for control purposes in high-production foundries making irons somewhat lower in carbon and silicon than indicated above. This test method is also preferable for applications in which the casting is to have a specified depth of chill.
7. Test Specimens 7.1 The patterns shall be made of metal and conform to the dimensions shown in Fig. 2. All dimensions shall be within 61⁄32 in. (0.8 mm) of those shown, with the exception of the length which may vary 6 1⁄8 in. (3.2 mm). The test specimens shown are designed to be cast in the position shown. This design is the preferred one, although for high-production work, a gang core box and pattern may be used. In this case, a test specimen with the chilled face in a vertical position may be found more convenient although it is not considered as satisfactory as the horizontally cast test specimen.
8. Procedure 8.1 Cores—Make the test in a core. For general application, a single core is considered more satisfactory than a gang core. If a gang core is used, the amount of sand between test specimens shall be 1 in. (25.4 mm) minimum or 21⁄2 × A (Fig. 2), whichever is greater. The remarks concerning cores in 4.1 apply here also. 8.2 Chill Plates—Chill plates may be cast iron, steel, copper, or graphite. Machine the surface of the chill plate. When single test specimens are cast, the chill plate shall extend at least 1 in. beyond the test specimens in all directions and shall be at least 1-in. thick. For high-production work, a sufficient number of chill plates must be available to keep the temperature of the plate below 500°F (260°C). A water-cooled steel plate will be found more satisfactory for high-production work. A water-cooled plate having a reservoir is preferable to one having circulating water. In the latter case the plate may become too cold, resulting in condensation of moisture on the plate. The chill plate must be kept free of the fire cracks and all foreign matter as the depth of chill is markedly affected by the presence of films of burned oil or other accumulations. The best practice is to clean off the plate with a wire brush as soon as the core and test specimen are removed. 8.3 Pouring Practice—Remarks on pouring practice in 4.2 apply here. In addition, do not pour iron directly on the chill plate as the depth of chill may be affected or the test specimen may burn on the chill plate. It may be desirable to place a weight on the core when pouring it as there may be a tendency for the core to lift as it is being poured.The opening in the core shall be free of sand fins and shall set flat on the chill plate. In the event the core does not fit the chill plate, rub it until it does. 8.4 Cooling of Test Piece—The remarks in 4.3 apply here. If rapid testing is desired, the chill test specimen may be quenched in water, starting with the edge farthest from the chilled edge.
9. Measurement of Chill 9.1 Break the test specimen in such a manner that the fracture is straight and follows the notch in the test specimen. The chill from the chilled face to the first appearance of a gray spot shall be designated as clear chill. The distance from the chilled face to the last appearance of a spot of white iron shall be designated as total chill. That portion of the chill affected zone between the clear chill and the total chill shall be designated as the mottled zone.As in Section 5, it will be found satisfactory for general structure and quality control purposes to measure chill from the chilled face to a location where the structure is approximately 50 % white iron, which is roughly half-way through the mottled zone. If the chill test is used for the control of iron for castings having a chilled surface for wear-resistant purposes, it would be desirable to measure and record clear chill. If the casting with a chilled surface is to have some machining operation in the proximity of the chilled surface, it may also be necessary to specify maximum depth of total chill as well as depth of clear chill. In all cases, the depth of chill shall be expressed in 1⁄32 in. (0.8 mm) and the size of the test specimen used shall be designated. For example, a
A367 − 11
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Copyright by ASTM Int'l (all rights reserved); Mon Aug 17 02:28:35 EDT 2015 Downloaded/printed by Suranaree University of Technology (Suranaree University of Technology) pursuant to License Agreement. No further reproductions authorized.
measurement recorded as 4C-12 indicates that test specimen design 4C was used and the depth of chill was 12⁄32 in. (9.5 mm).
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