Abstract:

In the consideration of the attenuation of ultrasonic,the actual sound power of several ultrasonics with different frequencies and power in the liquid was determined via the calorimetric method. Under the conditions with and without ultrasonic,the corrosion rates of zinc in the hydrochloric acid solution were determined by means of the gravimetric method. Moreover,by changing the ultrasonic frequency and power parameters,the relationships between the corrosion rate and these parameters were investigated. In addition,the morphology of zinc corrosion was observed by means of scanning electron microscopy,with the causes for the acceleration of zinc corrosion being also analyzed. The results show that( 1) the corrosion of zinc in the hydrochloric acid solution is significantly accelerated by ultrasonic,and ultrasonic cavitation plays an important role in the accelerated process; ( 2) at the same power,the low-frequency ultrasonic induces the cavitation more easily,thus making the corrosion rate higher; and( 3) when the frequency is constant and the power is not too high,the corrosion rate increases with the power increase.

Key words: ultrasonic, cavitation, corrosion, zinc, calorimetric method