Abstract
This specification covers magnesium-alloy sand castings. The castings shall conform to the chemical composition limits specified. The castings may be subjected to such heat treatment as deemed necessary to produce material that will conform to the requirements specified. Heat treatment shall be performed on the whole casting and never on a portion. Foundry control shall consist of examination of the castings by radiographic or other approved methods for determining internal discontinuities until the gating, pouring, and other foundry practices have been established to produce castings meeting the quality standards. The tension test specimens representing the castings shall conform to the requirements.
Scope
1.1 This specification covers magnesium-alloy sand castings designated as shown in Table 1.
(A) Limits are in weight % max unless shown as a range or stated otherwise.
(B) ASTM alloy designations were established in accordance with Practice B951. UNS designations were established in accordance with Practice E527.
(C) Includes listed elements for when no specific limit is shown.
(D) If iron exceeds 0.005 %, the Iron to Manganese ratio shall not exceed 0.032.
(E) Rare earth elements are in the form of Didymium, with not less than 70 % Neodymium, and the remainder substantially Praseodymium.
(F) Alloy EV31A is a patented composition, suitable for elevated temperature applications. Interested parties are invited to submit information regarding the identification of alternatives to these compositions to ASTM International. Your comments will receive careful consideration at a meeting of the responsible technical committee, which you may attend. ASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mentioned in this specification. Users of this specification are expressly advised that determination of the validity of any such patent rights, and the risk of infringement of such rights, are entirely their own responsibility.
(G) Other Rare Earths may also be present to a total maximum of 0.4 %. These Rare Earths shall principally be Cerium, Lanthanum, and Praseodymium.
(H) Total Rare Earths (TRE) are principally a mixture of Cerium, Lanthanum, Neodymium and Praseodymium. The Cerium content should not be less than 45% of TRE.
(I) Other Rare Earths shall be principally heavy rare earths, such as, Gadolinium, Dysprosium, Erbium, and Ytterbium. Other Rare Earths are derived from the Yttrium, typically 80 % Yttrium, and 20 % heavy rare earths.
(J) Zinc + Silver shall not exceed 0.20 % in WE43B.
1.2 The values stated in inch-pound units are to be regarded as the standard. The SI values in parentheses are provided for information only.
1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.
