The article investigates the impact of changes in the microstructure of steel 80R and the level of residual stress on relaxation resistance after thermomechanical processing. The test procedure consisted of electron microscopic and X-ray studies of steel 80R, as well as the testing of the stress relaxation. During the work obtained dependences of the relaxation resistance of the structural stability of the material obtained after thermomechanical processing with different heating temperature and tension force.