| The Portevin Le Chatelier effect and anneal hardening of cartridge brass sheets were investigated with expectation of finding a possinble correlation between the two phenomena. The Portevin Le Chatelier effect could be observed when a specimen was rolled less than about 20 pct. reduction, whereas measurable anneal hardening was observed in sheets rolled more than about 20 pct. reduction. About 20 pct. rolling reduction was, therefore, the interested strain range where the two phenomena could be effectively studied together. From sheets subjected to more than 20 pct. rolling reduction, maximum hardness was observed after annealing at 250℃ for ten minutes. When the same annealing treatment was applied to a 20 pct. rolled sheet specimen, its stress-strain curve showed the maximum value of stress fluctuation, Δσ. The result was attributed to the fact that the Portevin Le Chatelier effect and anneal hardening are associated with dislocation pinning by solaute atoms |
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