Residual stress eliminates the self-balanced internal stress remaining in the body after external force or inhomogeneous temperature field. Residual stresses are produced during processing and strengthening. For example, cold drawing, bending, cutting, rolling, shot peening, casting, forging, welding and metal heat treatment may cause residual stress due to plastic deformation or non-uniform phase transformation. Residual pressure is usually harmful. For example, after improper heat treatment, welding or cutting, residual stress may cause warpage or deformation or even rupture of components. Or cracks may appear on the surface after quenching and grinding. The existence of residual stress sometimes does not lead to immediate defects, and cracks and fractures occur when components are superimposed on the strength limit due to the superposition of the working stress and the residual stress during the working period. Most of the residual stresses can be eliminated by proper heat treatment. Residual stress is sometimes beneficial and can be controlled to improve the fatigue strength and wear resistance of components.


In the manufacturing process, steel pipe will be affected by various processes and other factors; when these factors disappear, if the effect and effect of the above components can not be completely disappeared, it will still have some impact and influence on the components. Inside, the effects and effects of this residue. Also known as residual stress.


Residual stress is the stress that exists when an object is in equilibrium without external factors.


Any stress which has no external action and keeps self-balance in the body is called the internal stress of the body, or the initial stress, also known as the internal stress.