【摘要】 研究了超细晶粒形变热处理６５Ｍｎ，６７Ｂ及７２Ａ钢丝制弹簧的应力松弛性能。在半对数坐标中，弹簧负荷损失率随时间变化可分为二个阶段，且均为直线，可以用：（Ｐ／Ｐ０）％＝ａ十ｈｌｎｔＲ表示。钢丝强度越高，负荷损失率越小，拐点左移，随着去应力退火温度升高，弹簧负荷损失率不是单调变化的，初始负荷越高，负荷损失率越大，但是第一和第二阶段松弛率变化却相反，拐点也将左移。指出应力松弛过程伴随有组织亚结构的变化。更多还原

【Abstract】 The stress relaxation properties of spring made of ultra-fine-grined and thermomechanical treated 65Mn, 67B and 72A steel wire are studied. In cordinates of (P/P0) %-IntR, the curve can be divided into two segments and both are in linear relation and showed: (P/P0) %=a+blntR. The higher the steel wire strength is, the smaller the loss rate of load and relaxation rate. The cross point of the two segments curve travels toward left. The loss rate of spring load don’t change simple with increase of the stress relief annealing temperature. The higher the initial load is, the higher the loss rate and the relaxation rate of the first segment. But the relaxation rate of the second segment will decrease, and the cross point travels’toward left. It is pointed that there is a change of substructure during stress relaxation.更多还原