Influence of ultrasonic vibration on mechanical properties and microstructure of 1Cr18Ni9Ti stainless steel

The effect of ultrasonic vibration on the mechanical properties and microstructure of 1Cr18Ni9Ti stainless steel is investigated. Along the horizontal direction, the molten alloy is treated by ultrasonic power of 400 W, 500 W, 600 W and 700 W, respectively. Experiment results show that considerable improvement of mechanical properties can be achieved attributing to the ultrasonic treatments. Furthermore, with the effect of radiation force of ultrasonic, long dendritic microstructure is broken into pieces. In particle, when ultrasonic power reaches to 700 W, long dendritic microstructure is disappeared and transformed into equiaxed one. Base on the experimental results and theoretical deduction, it is confirmed that radiation force induced by ultrasonic plays a decisive role in structure refinement. (C) 2006 Elsevier Ltd. All rights reserved.