At the suggestion of academician N. N. Davidenkova there are three types of residual stresses:
Voltage of the 1st kind - of macrolipasemia covering a region commensurate with the size and uravnoveshivaetsia within it. They have the orientation associated with the shape of the part.
Voltage of the 2nd kind microstresses acting within a single crystal, i.e. applicable to individual grains of metal, or a group of grains.
Voltage of the 3rd kind - submicroscopic, elementary, relating to the distortion of the atomic lattice of a crystal.
Ways to reduce and eliminate the residual stress
The main ways are:
Annealing, aging, vacation, etc.
The choice of a rational (from the point of view of targeting minimal residual stresses in the surface layer parts) of the methods and modes of treatment.
The choice of form, geometry and elementary surface, excluding the guidance of high residual stresses.
Choice of the rational scheme of mechanical processing, for consistent redistribution of residual stresses without significant deformation of the part. Which shall not exceed the amount of the allowance for subsequent processing of the surface and the value of dimension tolerance in the final processing.
A great influence on the characteristics of the surface layer provide the heat and himioterpevticescoy processing.