Analytical model for predicting coverage in suspension waterjet shot peening and its influence on fatigue

Abstract

Suspension waterjet peening is an emerging technology for surface modification. Coverage is a key factor affecting the integrity of a modified material surface, however such an experimental method that can be utilized for precise control has not yet been established. To determine the numerical value of coverage after surface peening treatment, In this paper, a coverage analytical method was proposed and then verified by the results through experiments. Furthermore, to explore the impact of high coverage on surface integrity, a large-scale coverage peening modification was performed on 18CrNiMo7-6 carburized steel specimens using a specialized suspension waterjet equipment. The results indicate that coverage has a significant impact on roughness and compressive residual stress field, with the highest improvement on surface and their maximum values reaching 51.6% and 24.7%, respectively. It is shown that the fatigue performance of the specimens can be significantly enhanced.

Study on Overlap of Carburizing 18CrNiMo7-6 Alloy Steel Strengthened via Abrasive Water Jet

“…4(a), and its chemical composition is listed in Table 1 (mass fraction). Its dimensions and properties were as follows: the thickness of the carburizing layer, 1.2 mm; hardness, 55-58 HRC; elastic modulus, 200 GPa; yield strength, 1230 MPa; Poisson's ratio, 0.3 [10]. Additionally, its original surface roughness S a was 1.3 µm (see Fig.…”

“…AWJ technology achieves uniform mixing before particles are ejected from the nozzle, and the high cluster energy of an AWJ is used to strengthen the key components of important equipment, thus causing dislocation slip, grain refinement, and plastic deformation in their tissues [4]. Consequently, a residual compressive stress field is formed [8], which can significantly improve the reliability and anti-fatigue life of the components [9] [10].…”