Corrosion resistant aluminum alloys having high amounts of magnesium and methods of making the same
Systems and methods for continuously casting Al—Mg alloy sheet or plate product having a high amount of magnesium are disclosed. The Al—Mg products have 4 or 6 to 8 or 10 wt. % Mg and are resistant to both stress corrosion cracking and intergranular corrosion.
1. A continuously cast Al—Mg alloy sheet product comprising from 6 to 10 wt. % Mg, wherein the continuously cast Al—Mg alloy sheet product realizes a mass loss of less than 25 mg/cm 2 when tested per ASTM G67-86.
2. The continuously cast Al—Mg alloy sheet product of claim 1 , wherein the Al—Mg alloy sheet product comprises a plurality of grains, wherein the grains have grain boundaries, and wherein the Al—Mg alloy sheet product is substantially free of a continuous film of β-phase at the grain boundaries.
3. The continuously cast Al—Mg alloy sheet product of claim 2 , wherein the grains of the Al—Mg alloy sheet product comprise Mg 2 Si precipitates; and wherein the Al—Mg alloy sheet product comprises at least 0.5 volume percent of Mg 2 Si precipitates based on a volume of the Al—Mg alloy sheet product.
4. The continuously cast Al—Mg alloy sheet product of claim 1 , wherein a thickness of the Al—Mg alloy sheet product is 0.25 inches or less.
5. The continuously cast Al—Mg alloy sheet product of claim 1 , wherein the continuously cast Al—Mg alloy sheet product realizes a mass loss of less than 15 mg/cm 2 when tested per ASTM G67-86.
6. An automobile part comprising the continuously cast Al—Mg alloy sheet product of claim 1 .
7. The continuously cast Al—Mg alloy sheet product of claim 1 , wherein the continuously cast Al—Mg alloy sheet is resistant to stress corrosion cracking when tested per ASTM Standard G44-88.
8. The continuously cast Al—Mg alloy sheet product of claim 1 , wherein the continuously cast Al—Mg alloy sheet product comprises from 6-7 wt. % Mg.
9. The continuously cast Al—Mg alloy sheet product of claim 1 , wherein the continuously cast Al—Mg alloy sheet product comprises from 8-10 wt. % Mg.
10. The continuously cast Al—Mg alloy sheet product of claim 9 , wherein the continuously cast Al—Mg alloy sheet is resistant to stress corrosion cracking when tested per ASTM Standard G44-88.
11. The continuously cast Al—Mg alloy sheet product of claim 1 , wherein the sheet product comprises a top outer layer, a bottom outer layer, and an intermediate layer disposed between the top and bottom outer layers.
12. The continuously cast Al—Mg alloy sheet product of claim 11 , wherein the top and bottom outer layers comprise equiaxed dendritic grains.
13. The continuously cast Al—Mg alloy sheet product of claim 12 , wherein the intermediate layer comprises globular grains and eutectic between the grains.
14. The continuously cast Al—Mg alloy sheet product of claim 13 , wherein the intermediate layer is absent of intermetallic particles.