Dynamic Elastic Modulus and Internal Friction in Fibrous Composites

Materials studies for magnetic fusion energy applications at low temperatures- III

“…Moreover, Ledbetter's elastic property measurements for the AISI 316 of this study confirm that Young's modulus is anomalous below 60 K, and therefore, the magnetic transition probably occurs in this alloy [16].…”

“…Given consistent weldin-g conditions, a decrease in the deltaferrite content of the weldment results in an increased cryogenic fracture toughness [2] However, the production of very low ferrite or fully austenitic weldments can be difficult because these weldments are apt to form microfissures. The subject of microfissuring has been extensively studied [12][13][14][15][16], particularly with regard to the effects of del ta-ferrite content and chemical composition. It is generally agreed that microfissuring is the result of a liquation process, where a lowmelting temperature grain-boundary constituent is remelted by the subsequent welding pass.…”

“…Charpy vee notch ft-lbs (mils) @-150 78.8 (38) 83.9 (43) 36.9 (15) 39.0 (4o;1 19.5 (10]1 41.2 (24) 73.8 (29) 77.4 (41) 36.2 (19) 49. 32.5 (18) 32.5 (22) 13.7 ( 65.3 (39) 80.3 ( 47 ;1 32.0 (16) 34.7 (27) 14.0 ( 7] 1 29.2 1(21) @-250F 54.2 (27) 70.9 (44] 1 27.5 OD 23.9 (14) 13.0 ( 6) 1 27.5 ( :i6) 62.9 (27) 60.7 ( 55.4 (27) 68.0 ( 39 ) 1 27.0 (11) 28.9 (17) 13.5 ( 7 ) 24.6 (. 14 ) @-320F 41.2 (12) 52.1 (26) 1 21.0 ( 2) 25.3 (18) 11.6 ( 1) 31.8 (17) 47.7 (24) 62.2 (31) i 21.0 ( 2) 20.2 (15) 10.1 ( 3) 31.1 (15) 39.8 (18) 61.5 (39) 22.4 ( 2) 23.9 (17) 13.7 ( 5) 23.1 (12) avg.…”

“…This difference signal is the required change-of-displacement signal and is converted to digital form with 16 bit resolution of its 80 mV range.…”

“…The second procedure with the tubular wire was machine SA welding at 300 amps, 29 volts DCRP, 16 inches per minute travel, 1-inch electrical extension with Lincoln STIOO flux. The 1-inch 304L plate used a single-pass root on each side, one 2-pass layer on one side and two 2-pass layers on the second side, and one 3-pass layer on each side for a total of 14 passes.…”