Influence of Combined Shot Peening and High-Temperature Pulsed Plasma Treatment on the Fatigue Life of Structural Steels

The article considers the effectiveness of combined surface treatment of 30KhGSA and 30KhGSN2A steels by shot peening (SP) and high-temperature pulsed plasma treatment (HTPP). An optimal combination SP + HTPP + SP is identified: it achieves a 15–20-fold increase in the cyclic fatigue life of ground specimens, and a twofold increase for initially shot-peened specimens. It is also shown that HTPP treatment (in selected modes in a helium environment) reduces the fatigue life of specimens by a factor of 2‒4 or more, regardless of previous machining. The results were confirmed by fatigue tests of steel specimens with a smooth surface and with a stress concentrator.