Analysis of the Local Stress Field of the Steel Surface under Pneumatic Impact Repairing Technique

Experimental research on local stress surface under pneumatic impact technique was carried out. The variation law and hardening degree of residual stress field on the surface of components under impact were analyzed from macroscopic and microscopic perspectives. Meanwhile, the static equivalent model of pneumatic impact was established to analyze the influence of different impact parameters on the distribution of residual stress field. The results indicated that the residual compressive stress on the surface of the specimen is increased after impacting, while the trend seems to slowed down. The lattice size of the steel surface decreases, and the hardening degree increases. The finite element analyzing results show that residual compressive stress can be produced obviously under impact. With the increase of material hardening degree, the increase of impact frequency has no obvious effect on the improvement of residual compressive stress, while the larger impact head made the distribution of residual compressive stress more uniform.