逆張力附加引抜法の研究（第5報）燐青銅線に関する実験

Abstract

Wire drawing with back tension was carried out on face centered cubic materials, mainly phosphor bronze wire containing 6% Sn. The results are as follows: (1) The effects of back tension on drawing force, die pressure, stress distribution in the wire within die channel, every work consumption and efficiency of deformation have the same tendencies as in the drawing of iron wire and carbon steel wire. (2) At low reduction, as the back tension increases, the tensile strength and the yield strength of the drawn wire decrease to some degree, but the elastic limit and the Young’s modulus rather increase. (3) The elastic limit of the drawn wire with 40% back tension ratio is about 16% higher than that of the ordinarily drawn wire at the same 60% reduction. (4) The difference between the elastic limits of wires drawn by the ordinary method and the back tension method becomes larger as the bak tension ratio increases, but the difference becomes nearly constant when this ratio exceeds 40%. (5) After low temperature annealing of hard drawn wires by both methods, the elastic limit increases owing to the strain aging, but its effect is more marked in ordinarily drawn wire. (6) After annealing with recrystallization, the elastic limit of drawn wire with back tension is about 11% higher than that of ordinarily drawn wire. (7) When the crystallographic anisotropy of the elastic limit of face centered cubic material is calculated in all directions, the elastic limit in [111] direction is 1.5 times as high as that in [100] and [110] directions. (8) Observation of X-ray fibre structure photographs reveals that the fibre degree of the internal part of wires drawn with and without back tension are almost equal but the fibre degree of the external part of the former is higher than that of the latter. (9) The excellence of the elastic property of the phosphor-bronze wire drawn with back tension is illustrated theoretically from the superiority of [111] fibre degree which has the highest elastic limit and the decrease of nonuniform microscopic stress which injures the elastic property.