残余应力是在无外力的作用时，以平衡状态存在于物体内部的应力。在外力的作用下，当没有通过物体表面向物体内部传递应力时，在物体内部保持平衡的应力统称固有应力或初始应力。热应力和残余应力是固有应力的一种，而固有应力也称为内应力。
目前广泛使用振动时效设备来代替热时效等来消除残余应力，取得了很好的效果，环保高效，受到行业的欢迎。
The residual stress is the stress in the interior of the body when it has no external force. Under the action of external force, when the stress is transferred to the object through the surface of the object, the internal stress of the object is called the inherent stress or initial stress. Thermal stress and residual stress are one kind of inherent stress, which is also called internal stress.
残余应力产生的原因，可分为因外部作用的外在原因，和源于物体内部组织结构不均匀的内在原因
The reason of the residual stress can be divided into the external reason of the external action, and the internal reason of the internal structure of the object.
1.不均匀变形
1 inhomogeneous deformation
不均匀的变形状态，是不均匀塑料变形产生的条件。
Inhomogeneous deformation state is the condition for the production of inhomogeneous plastic deformation.
外在原因；不均一的作用应力，例如弯曲、压延、拉拔。
External causes; inhomogeneous stress, such as bending, rolling, drawing.
内在原因；由于物体内各部分组织的浓度差或晶粒的位向差等，各部分显示的不同的屈服行为。
The intrinsic reasons; due to the concentration difference of objects within the organization or grain misorientation etc., display the different yield behavior.
2.热的作用
2 heat effect
（1）热应力产生的塑性变形；当加热、冷却过程中产生热应力时，由于高温下屈服强度低，在这种应力作用下易于产生塑性变形。
(1) the plastic deformation produced by the thermal stress, when the heat stress is produced in the process of heating and cooling, the yield strength is low at high temperature, and it is easy to produce the plastic deformation under the action of the stress.
外在原因：物体各部分的弹性模量、导热系数热膨胀系数等不同而且它们的温度也不相同
External reasons: the elastic modulus of the various parts of the body, thermal expansion coefficient of thermal conductivity and so on, and their temperature is not the same
（2）相变或沉淀析出引起的体积变化
(2) the volume change induced by phase change or precipitation
外在原因；冷却时，各部分的冷却不均匀，冷却速度也不同。故而当出现有完全相变终了的部分和相变尚未进行的部分时，两者便显出体积变化的差异。内在原因：在具有组织结构的浓度差时， 固相变和沉淀析出等，所引起的体积变化的程度也不同。
External reason; when cooling, the parts of the cooling is not uniform, the cooling rate is also different. As a part of the complete phase transition and the phase transition have not yet been carried out, they show the difference in volume change. Internal reason: in the concentration difference with the structure, the solid phase change and precipitation, etc., caused by the volume change of the degree is also different.
残余应力的去除和调整
Removal and adjustment of residual stress
1.退火去除法
1 anneal to Division
2.自然失效去除法
2 natural failure to Division
3.用静态作用应力去除法
3 use static stress to divide
4.振动时效去除法
4 vibratory stress relief