Determination of threshold velocities and correlation of high-frequency endurance limits for LMFBR heat-exchanger materials

摘要

Jet impact erosion tests and high frequency fatigue tests were conducted for 2-1/4 Cr-1 Mo steel. Utilizing the relationship between the velocity of impact and number of impacts to produce visible erosion, the threshold velocities were determined as 220 and 140 fps at 10/sup 7/ and 10/sup 8/ cycles respectively. The relationship between the high frequency fatigue strength and the number of cycles to failure was determined at room temperature up to a maximum of 10/sup 9/ cycles. The high frequency endurance limit at room temperature was determined to be approximately 32,000 psi for 10/sup 8/ cycles. In addition, the ratio of high frequency fatigue strength to water hammer stress for erosion inception was also obtained as 2.75. 5 figures.