ASTM B618/B618M-18,Standard Specification for Aluminum-Alloy Investment Castings.ASTM B618/B618M-18 pdf free download.
ASTM B618/B618M-18 covers aluminum-alloy investment castings designated as shown in Table 1.(A) When single units are shown, they indicate the maximum amounts permitted.
(B) Analysis shall be made for the elements for which limits are shown in this table.
(C) The following applies to all specified limits in this table: For purposes of determining conformance to these limits, an observed value or a calculated value obtained from analysis shall be rounded to the nearest unit in the last right-hand place of figures used in expressing the specified limit in accordance with the rounding-off method of Practice E29.
(D) In case of discrepancy between the values listed in Table 1 and those listed in the “Designations and Composition Limits for Aluminum Alloys in the Form of Castings and Ingot (known as the ‘Pink Sheets’),” the composition limits registered with the Aluminum Association and published in the “Pink Sheets” shall be considered the controlling composition.
8. Material Requirements-Castings Produced for
Governmental and Military Agencies
8.1 Unless otherwise specified, only aluminum alloy con forming to the requirements of Specification B I79 or produc ers foundry scrap (identified as being made from allo conforming to Specification B I79) shall be used in the remelt- ing furnace from which molten metal is taken for pouring directly into castings. Additions of small amounts of modifiers and grain refining elements or alloys are permitted.
8.1.1 Pure materials, recycled materials, and master alloys may be used to make alloys conforming to this specification provided chemical analysis can be performed and the compo sition of the melt adjusted to conform to Table I prior to pouring any castings.
14. Workmanship and Finish
14.1 The finished castings shall be uniform in composition and free of blowholes, cracks, shrinks, and other injurious defects except as designated and agreed upon as acceptable by the purchaser.
5. Beat Treatment
15. 1 Heat treatment of castings shall be performed in accordance with Practice B917/B917M.
15.2 When specified, heat treatment shall be in accordance with AMS 2771.