SRI has developed a new technology that analyzes failures in aging refinery vessels and pipes to disclose when cracks nucleated and how fast they grew. The technology is expected to lead to new ways to predict, extend, and monitor component life.

The technology, called FRASTA (FRActure Surface Topography Analysis), is a major advance in fractography that allows a failure event to be replayed in microscopic detail. Besides providing mechanistic and microstructural information not obtainable from conventional fracture surface examination, FRASTA can often provide the history of a crack and the fracture toughness of the material.

For example, when FRASTA was applied to a part-through crack in a 22-year-old boiler tube in a fossil fuel power plant, we determined that the crack nucleated after 68,000 hours of operation and that acceleration and deceleration phases of crack growth occurred during plant operation. We were able to determine the crack growth rate during the entire operation and correlate changes in crack growth with chemical cleanings and hot starts. Such information can be used to alter the operation and maintenance conditions of the plant to extend plant life and set more realistic inspection schedules to ensure safe plant operation.

FRASTA can thus provide the understanding of failure in chemical processing components required to develop lifetime predictive capability for new or in-service systems and provide earlier warning of impending failure. Further, the improved knowledge of degradation processes in aging components is expected to lead to new ways to extend life and new techniques for inspecting a component's health.

Dr. Donald A. Shockey Associate Laboratory Director

Phone (650) 859-2587 e-mail: dshockey@unix.sri.com

Dr. Takao Kobayashi Sr. Research Engineer

Phone (650) 859-5571 e-mail: kobayash@unix.sri.com