ASTM B91 : 12

Standard Specification for Magnesium-Alloy Forgings

Standard Details

1.1 This specification covers magnesium alloy forgings designated as shown in Table 1.

TABLE 1 Chemical Composition Limits^A^,^B

Note 1—Analysis shall regularly be made only for the elements specifically mentioned in this table. If, however, the presence of other elements is suspected or indicated in amounts greater than the specified limits, further analysis shall be made to determine that these elements are not present in excess of the specified limits.

Note 2—The following applies to all specified limits in this table. For purposes of acceptance and rejection, an observed value or a calculated value obtained from analysis should be rounded to the nearest unit in the last right-hand place of figures used in expressing the specified limit.

	Composition, %
Element	Alloy AZ31B (UNS No. M11311)	Alloy AZ61A (UNS No. M11610)	Alloy AZ80A (UNS No. M11800)	Alloy ZK60A (UNS No. M16600)
Magnesium	remainder	remainder	remainder	remainder
Aluminum	2.5–3.5	5.8–7.2	7.8–9.2	...
Manganese	0.20–1.0	0.15–0.5	0.12–0.5	...
Zinc	0.6–1.4	0.40–1.5	0.20–0.8	4.8–6.2
Thorium	...	...	...	...
Zirconium, min	...	...		0.45
Silicon	0.10	0.10	0.10	...
Copper	0.05	0.05	0.05	...
Nickel	0.005	0.005	0.005	...
Iron	0.005	0.005	0.005	...
Calcium	0.04	...	...	...
Other impurities^C	0.30	0.30	0.30	0.30