HIGH TEMPERATURE, LOW-CYCLE FATIGUE OF COPPER-BASE ALLOYS IN ARGON;PART II - ZIRCONIUM-COPPER AT 482, 538 AND 593°C.

摘要

Zirgonium-copper (1/2 hard) was tested in argon over the temperature range from 4.82℃° to 593 ℃ in an evaluation of short-term tensile and low-cycle fatigue behavior. The effect of strain rate on the tensile properties was evaluated at 538 C and in general it was found that the yield and. ultimate strengths increased as the strain rate was increased from 4 x 10-4- to 1 x 10-2 sec-1 Ductility was essentially insensitive to strain rate in the case of the zirconium-copper alloy. Strain-rate and hold-time effects on the low cycle fatigue behavior of zirconium-copper were evaluated in argon at 538℃. In general, these effects ware as expected in that decreased fatigue life was noted as the strain rate decreased and when hold times were introduced into the tension portion of the strain-cycle. Hold times in compression were much less detrimental than hold-tines in tension and, in fact, did not appear to have any effect on fatigue life. An analysis of the relaxation behavior in tension and compression is presented.