Preliminary evaluation of cavitation resistance of type 316LN stainless steel in mercury using a vibratory horn

Influence of Heat Treatment on Mercury Cavitation Resistance of Surface Hardened 316LN Stainless Steel

“…Mill-annealed (as-received) 316L stainless steel-with and without the carburizing process but no subsequent heat treatment-was also included in the cavitation test matrix via previous evaluation [13,15]. It should be noted that these particular heat treatments were not selected to simulate a specific weld thermal cycle or any anticipated treatment; rather, they were selected simply as representative of a range of potentially deleterious possibilities useful to evaluate sensitivity to thermal treatment.…”

“…Each test specimen had a surface area of 180 mm 2 exposed to cavitation conditions and was attached to the vibratory horn tip via a threaded shank (other specimen details are reported in [13]). In each test, the horn tip oscillated at a fixed frequency of 20 kHz with a peak-to-peak vibrational amplitude of 25 µm.…”

“…that the specimen heat treated 30 min at 500°C exhibited among the highest residual hardness in the carburized layer, but the specimen heat treated 30 min at 800°C was comparatively low at many measurement points (yet it retained superior cavitation-erosion resistance compared to specimens heat treated at 650°C). Clearly, surface hardness is not the only factor influencing cavitation resistance [13]. Following sonication and optical microscopy to examine surface roughening and pit depth, specimens were examined in the SEM to assess topography in more detail.…”

“…However, annealed 316/316LN stainless steel has been shown to be quite susceptible to pitting and erosion damage in mercury when tested under cavitation conditions produced by a split Hopkinson pressure bar apparatus [4] or a drop-test variant [5], in-beam exposures [6][7][8][9], and a vibratory horn [10][11][12][13].…”

Evaluation of Cavitation-Erosion Resistance of 316LN Stainless Steel in Mercury Containing Metallic Solutes

“…It has been shown that the cavitation-erosion resistance of annealed 316LN may be improved by hardening the material via surface treatments and/or cold-working. 10,11 Further, cavitation-erosion resistance of alternate materials may be somewhat superior to 316LN, but these alternate materials may exhibit less desirable or less well known 10 properties for other aspects of the target service requirements.…”