45冷轧钢拉应力作用的力-磁效应研究

在不同的最大拉应力作用下，反复加载．卸载，测量了45冷轧钢试件在加载和卸载过程中试件表面某确定点漏磁场随拉应力的对应关系。试验结果表明，当最大拉应力＜610MPa时，磁感应强度随应力的变化关系为线性关系。当最大拉应力处于610MPa与屈服点653MPa之间时，磁感应强度随应力的关系由直线关系变为折线关系，并且折线极值点的位置由较小应力处迅速变为较大应力处位置。在极值点位置向高应力方向移动过程中，磁感应强度的变化量迅速增大。当最大拉应力大于屈服点时，磁感应强度的变化量保持较大的状态，折线极值点的位置基本保持不变。得到了试件在拉应力作用下的磁化关系，同时证实了可以通过磁信号的大小对试件的安全性做出评估。

Studies on stress-magnetic effects for 45 steel components

The relationships of magnetization and stress with different maximum stresses of 45 steel items were measured, during process of extend and shrink. It indicated that when maximum stresses smaller than 610MPa, the relationships of magnetization and stress are linearity, which may estimate loading condition of items. When the maximum stresses is larger than 610MPa and smaller than bend point of 653MPa, the relationships of magnetization and stress have become bending line and the position of extremum of bending line rapidly increases to maximum. When the maximum stresses are larger than bend point of 610MPa, the change of magnetization with the stress and the position of extremum of bending line remains constant. It shows that the relationships of magnetization and stress have been obtained and that we may make security estimate for ferromagnetic items make use of magnetic signal.