Method of manufacturing magnesium alloy molded product, painted structure thereof, method of painting the same, and casings using the same

A method of manufacturing a magnesium alloy molded product, comprising the steps of:

• melting all or a part of a magnesium-aluminum alloy containing 4 to 12% aluminum;
• applying a release agent on a surface of a mold;
• injecting a melt of said magnesium alloy into a mold cavity heated to a predetermined temperature between 200° C. and 300° C. to form a molded body;
• and
• removing flow parts such as sprue, runner and melt basin from a product part of said molded body taken out of the mold.

A method of painting a magnesium alloy molded product, comprising the steps of:

• forming an anticorrosive film on a surface of a magnesium alloy molded product having flow marks with a depth greater than zero and a maximum depth is 100 μm and maximum opening width of 0.5 mm;
• applying a powder paint on a surface of the anticorrosive film, said powder paint having a curing-start temperature of 140° C. or lower;
• and
• curing and baking the powder paint that has been applied.