Ultrasonic Impact Treatment Equipment for steel Stress relief

he new generation Ultrasonic Impact Treatment (UIT) equipment is based on Piezoelectric Ceramic Transducer ( PCT ) technology, first developed by Sunbowtec for use around the world in 1995. It's the new direction of UIT technology and has already received international recognition.

ADVANTAGES

• HIGHER EFFICIENCY
  • Transfermation rate of piezoelectric ceramic transducer is nearly 50% higher than that of megnetostriction transducer(MT).
• DIGITAL CONTROL
  • Closed-loop control with DSP chip ensures stabilization of the generator unit.
• NO WATER COOLING REQUIRED
  • The ( PCT ) transducer generates less heat than ( MT ) type transducers. Therefore only integral fan cooling of the (UIT) tool is required.
• DUTY CYCLE
  • Over 16 hours of continuous operation if required.
• APPLICABILITY
  • Suitable for all metallic materials such as high strength steel of 1400 MPa, titanium alloys, aluminium alloys, etc.

1. The theory of ultrasonic impact treatment

Ultrasonic impact treatment equipment is consisted of 2 parts. One is ultrasonic impact gun and the other is power control box. This equipment gives the high power to the head of the impact gun, forcing it to impact the metal surface at a speed of over 20,000 times per second, which makes the surface a great plastic transmogrification. At the same time, the impact changes the stress field, dispersing tension stress while transforming it into beneficial compression stress. Also, the sharp increase and decrease of the surface temperature changes the surface metal organization so that enhance it.

2. How to increase the fatigue life by UIT(ultrasonic impact treatment)

Normal welding usually leaves defects in the joint part, including excess weld metal, rut, undercut and so on, which causes serious stress centralization. Meanwhile, welding causes residual stress. All these factors above do harm to the fatigue quality. Also, these is usually dross in the surface of toe zone, which accelerates the outburst of fatigue crack..

Using UIT equipment to process toe zone after welding, we can make a smooth transition to decrease stress centralization by excess weld metal, dispersing defects in the surface of toe zone. At the same time, it creates compression stress there by compression plastic deformation and adjust residual stress field, enhancing the intensity and hardness of toe zone.