SAE J 465-1989 镁铸件合金

标准号：SAE J 465-1989
中文标准名称：镁铸件合金
英文标准名称：Magnesium Casting Alloys
标准类型：T05
发布日期：1989/1/1 12:00:00
实施日期：1999/12/31 12:00:00
中国标准分类号：T05
国际标准分类号：77.120.20
引用标准：ASTM B 275-1980;ASTM B 296-1967;ASTM B 557-1984
适用范围：This document has not changed other than to put it into the new SAE Technical Standards Board Format This SAE Standard covers the most commonly used magnesium alloys suitable for casting by the various commercial processes. The chemical composition limits and minimum mechanical properties are shown. Over the years, magnesium alloys have been identified by many numbering systems, as shown in Table 1. Presently, SAE is recommending the use of the use of the UNS numbering system to identify those materials. Other equally important characteristics such as surface finish and dimensional tolerances are not covered in this standard. 1.1 Sources of Magnesium—Sources of Magnesium—Magnesium is the third most abundant structural element in the earth's crust, and considered inexhaustible. Common sources are sea water, natural brines, magnesite, and dolomite. Three methods of extraction are used in the United States. One method involves treating sea water with a source of alkalinity to precipitate the magnesium as hydroxide, mixing with hydrochloric acid to produce hydrated magnesium chloride, and then partially drying. The hydrous magnesium chloride is reduced electrolytically to produce magnesium metal and a mixture of chlorine and hydrochloric acid. A second method produces co-products magnesium metal and pure chlorine in the electrolytic cell by the reduction of anhydrous magnesium chloride or by the chlorination of MgO. The anhydrous cell feed results from the complete dehydration of natural brines. Another method of extraction, which is also used in the United States and in other countries, is by thermal reduction of magnesium oxide by ferrosilicon. Most of the magnesium ingot sold is of 99.80% purity. Grades of magnesium of 99.90, 99.95, and 99.98% purity are also available. The higher purity grades are used mostly in nuclear applications and for reduction purposes.