在金属切削加工中,我们常常遇到残余应力(或内应力)这样的字眼。所谓“内应力”就是物体本身内无需外力的作用而能自行平衡的应力。内应力可分为两种,一种是临时应力,另一种是残余应力。临时应力当去掉产生应力的原因时,立即消失,例如,在物体的各部分如果有不同的温度时,就会产生热应力,它是一种临时应力。当物体各部分的温度相等时,热应力便消失了。 In metal cutting, we often encounter the words residual stress (or internal stress). The so-called “internal stress” is the object itself without the role of external forces and can balance their own stress. Internal stress can be divided into two kinds, one is temporary stress, the other is residual stress. Temporary stress, when removed from the cause of the stress, disappears immediately. For example, if there are different temperatures in different parts of the object, it will generate thermal stress, which is a kind of temporary stress. When the temperature of each part of the object is equal, the thermal stress disappears.