Explanation

In the process of quench aging, for the determined alloy system, the most fine precipitation phase particles with dispersion distribution can be obtained by holding at the determined temperature for the determined time, thus obtaining the peak values of strength and hardness. When the aging temperature is low or the holding time is too short, due to the insufficient precipitation phase process, the strength and hardness have not reached the peak value, it is called under aging. Since the aging effect has not been reached, its performance and workpiece size are unstable, so it is rarely used. When the aging temperature is too high or the holding time is too long, the strength and hardness decrease from the peak value due to the increase of precipitation phase particle size, which is called over aging. Appropriate over aging treatment can significantly increase the plasticity and toughness under the condition that the strength and hardness decrease slightly, and over aging treatment is adopted when the requirements for performance stability are high.

Classification