Various types of austenitic stainless steel (SS) were aged for up to 2500 h at a temperature of 600C to determine whether the resultant microstructural changes would affect the ultrasonic velocity and attenuation and thus the reliability of ultrasonic in-service inspections. Samples of Type 304 and 316 SS as well as 308, 308CRE, and 316 weld metal were examined. Velocity variations were less than 1%, and attenuation variations at frequencies below 10 MHz were not significant except in the anomalous case of one Type 316 SS weldmetal sample. That change may be due to unexpected microstructural changes associated with aging. The variation in the samples attributed to aging is therefore not expected to have a deleterious effect on ultrasonic in-service inspection of stainless steel reactor components.

This proceedings covers instruments and process control involved in the conversion of fossil fuels into synthetic fuels, spurred in part by response to the energy crisis of the 1970s and attending inflation.