Effect of Prestressed Shot Peening on Residual Stress and Microhardness of C63020

Author:  Chengxi Wang, Chuanhai Jiang, Henry Pan
Source:  ICSP-13
Doc ID:  2017069
Year of Publication:  2017
Introduction: Nickel aluminum bronzes (NAB) are widely used range from seawater pumps, valves and propellers to landing gear bearing and bushings due to their unique combination of high strength, good damping capacity, excellent wear and corrosion resistance [1]. However, these alloys can also be subjected to selective phase corrosion and stress corrosion cracking when they working in seawater or other extreme conditions due to their complex phases and inhomogeneous distribution of residual stresses [2]. In most cases, the surface is more likely to be failure than the central part. Hence a number of studies have been carried out recently to enhance the surface mechanical properties and the corrosion resistance including friction stir processing [3] and laser cladding [4]. These techniques can refine the grains or homogenize the microstructure [5]. In comparison, shot peening (SP) as one of the mostly used methods to improve the surface properties of components, can simultaneously refine the microstructure and induce the compressive residual stress (CRS) into the surface layers. As we know that CRS can also enable the components have excellent resistance against the stress corrosion cracking. In order to further enhance the helpful effect of CRS, the prestress treatment is usually used during SP process. Other investigations have also confirmed that the prestress can introduce higher CRS than that of traditional SP [6,7]. However, the effect of SP on the nickel aluminum bronze with prestress treatment has not enough been investigate.

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