7A04 aluminum alloy is an important aluminum alloy material in aircraft manufacturing. 7A04 aluminum alloy has high strength and toughness, fatigue resistance and corrosion resistance.
In aluminum alloy induction heat treating process with induction heating furnace, we must pay attention to prevent the occurrence of workpiece overburning defects. This is due to the narrow range of aluminum alloy heating, and more than the standard heating temperature slightly or heating time is too long, so it has the problems of parts overheating and overburning. Workpiece burned defects are difficult to repair, resulting in product scrapped. In this regard, we did the production test and analysis, and then obtained useful test results.
According to the test and analysis, in order to prevent the phenomenon of overheating, we recommend the use of bars induction heating machine to solve the defects of aluminum alloy overburning. Among them, the recommended process temperature should be 465-475 ℃, and the induction heating time is calculated as the effective heating thickness or diameter of the workpiece.
In order to strictly prevent the workpiece heating temperature is too high, the heating temperature should not exceed 495 ℃. When the workpiece is at 480 ℃ for heating, the induction heating equipment can strictly control the workpiece holding time. And if 7A04 aluminum alloy is heated at 480 ℃ and then carried out insulation with 150min, it will appear over burning, so this is a cordon; when the holding time is 90min, the workpiece metallographic structure is normal.