Engineering the residual stress state and microstructure of stainless steel with mechanical surface treatments

Abstract

Four mechanical surface treatments have been considered for the application to austenitic stainless steel structures. Shot peening (SP), laser shock peening (LSP), ultrasonic impact treatment (UIT) and water jet cavitation peening (WJCP), also known as cavitation shotless peening (CSP), have been applied to 8 mm thick Type 304 austenitic stainless steel coupons. This study considers the merits of each of these mechanical surface treatments in terms of their effect on the surface roughness, microstructure, level of plastic work and through thickness residual stress distribution. Microstructural studies have revealed the formation of martensite close to the treated surface for each process. Residual stress measurements in the samples show compressive stresses to a significantly greater depth for the LSP, UIT and WJCP samples compared to the more conventional SP treated sample.

Investigation of laser shock peening effects on residual stress state and fatigue performance of titanium alloys

“…These results agree with the previous studies about the influence of LSP and BB on the residual stress state and work hardening of Ti-6Al-4V [2]. Turski et al [7] compared the efficacy of ultrasonic impact treatment (UIT), LSP and water jet cavitation peening (WJCP) at introducing residual stresses and modifying the near surface state compared to SP benchmark for AISI 304. It was concluded that WJCP and LSP introduced the lowest levels of surface roughening.…”

Numerical Simulation of Residual Stresses in Welding and Ultrasonic Impact Treatment Process

“…It was noteworthy that the maximum compressive stresses in the longitudinal direction for both butt joint and T-joint were relatively higher than the compressive limit of 304L steel, which implied cold working by the UIT induced plastic deformation of the weld joint. The similar level of compressive residual stresses higher than the material's yield limit was also obtained and reported by previous studies [11,28,32].…”

“…In most of the cases, it has been found that the UIT introduces compressive residual stresses along varying depths and improves fatigue performances of weld joints in various extent. Turski et al [11] found that the UIT produced compressive residual stress fields of about 2 mm in depth for 304 stainless steel. Liu et al [12] measured residual stresses of UIT-treated high strength steel weld joints.…”

“…A number of numerical models have been developed to predict the residual stress distribution and fatigue performance of UIT-treated weld joints [13,15]. Meanwhile, experimental studies of the UIT have been also conducted [11,12,14]. Various measurement techniques such as X-ray diffraction and neutron diffraction were used to obtain experimental data for the validation of simulated residual stresses.…”

“…In recent years, numerous studies have been carried out to investigate effects of the UIT on the weld residual stresses and fatigue performance of weld joints [11][12][13][14]. A number of numerical models have been developed to predict the residual stress distribution and fatigue performance of UIT-treated weld joints [13,15].…”