CF Industries Dragline Life Extended 4x (and counting- still no cracking), saving at least $1.5 Million in repair/downtime costs

In September 2009, Applied Ultrasonics treated weld connections on the A-frame and propel structure of a Page 852 dragline owned by CF Industries with their patented UIT (Ultrasonic Impact Technology).
In the past, these welds would crack every 2-3 months and fail every 6 months, requiring repair and associated downtime, year after year, for the entire 15 years of the asset’s service.

The Ultrasonic Impact Treatment was done during a repair outage with one crew over a period of 3 days. The UIT crew supported several welding crews making repairs, yet due to the speed and efficiency of UIT, only added a few hours to the total repair time.

Since the UIT treatment, CF Industries has not had any problems with cracking and has not had to take the dragline out of service for weld repairs. UIT extended the time between failure by at least FOUR TIMES and has saved CF Industries at least $1.5 million in repair and non-productive time (downtime) costs.

Original post: http://appliedultrasonics.com/news.html#-2

Combating Steel Fatigue with Ultrasonic Impact Treatment

Steel fatigue occurs when a metal structure or component is subjected to repeated loading and unloading of stress on a specific part (similar to bending a paper clip or staple back and forth repetitively until it breaks).  When this process, also known as cyclic loading, exceeds a specific limit, tensile cracks form on the surface and alters microscopic grains within the metal which ultimately lead to fatigue failure if left untreated.  Outside of replacing the metal, Ultrasonic Impact Treatment from Applied Ultrasonics has emerged as the most effective method of combating steel fatigue due to its ability to improve surface quality, force detrimental tensile stresses deep within the material, and reform the grains that comprise the structure of the metal. 

*Example of cyclic loading and its effect on steel fatigue.