Fatigue Resistance of Low Alloy Steel after Shot Peening

Abstract

It is well known that shot peening is able to increase the fatigue strength and endurance of metal parts, especially with a steep stress gradient due to a notch. This positive effect is mainly put into relation with the ability of this treatment to induce a compressive residual stress state in the surface layer of material and to cause surface work hardening [1]. In this paper shot peening is applied on the 40NiCrMo7 low alloy steel and subsequently the surface was re-peened with glass beads to decrease the final surface roughness. Roughness, hardness and residual stress analysis were used for characterizing the strongly deformed surface layer. Low frequency fatigue tests were carried out to evaluate the effect of the applied treatment on fatigue life in the high cycle region. Results show fatigue strength increase in the high cycle region after the shot peening surface treatment

Electrochemical Corrosion Characteristics of High Strength Low Alloy Domex 700 Steel After Mechanical Surface Treatment in Chloride Environment

“…Veľký počet dopadov guľôčok a prekrytie jamiek vytvorí pod povrchom rovnomerné tlakové napätie. Pretože väčšina porušení súčiastky únavou alebo koróziou pod napätím sa iniciuje na povrchu, tlakové napätie indukované tryskaním predlžuje čas potrebný na iniciáciu trhliny a tým aj celkovú životnosť súčiastky alebo zariadenia z hľadiska porušenia únavou materiálu [15][16][17][18]. O vplyve technológie tryskania na korózne vlastnosti povrchu ocele Domex 700 patriacej do skupiny HSLA ocelí však nenájdeme žiadnu relevantnú publikáciu, a preto sme sa tejto problematike rozhodli venovať v tejto štúdii.…”

Investigation of fatigue strength of aluminium 2024-T3 subjected to shot peening process by Ni shots

“…Recent research works also proved that intensity of shot peening process increases the fatigue strength [2]. Fatigue life depends on various factors like relaxation level of the stress layer, surface modification created by peening process and the compressive residual field induced [3]. From experimental investigations, it was observed that enhancement of fatigue life was influenced by arresting crack formation.…”

The influence of partial surface shot peening on fatigue crack growth behaviour of a high‐strength ferritic steel

“…Moreover, Klocke et al proposed a feasible method for assessing the homogeneity of residual stress distribution on shot peened steel. 17 A review of the past studies has revealed that shot peening effects on fatigue crack initiation and growth were examined by applying this surface treatment technique on the entire surface of the steel samples. They found that the fatigue behaviour of this material improved by surface peening process and the best fatigue performance obtained with the specimens that were shot peened at 20 Almen intensity and 100% saturation.…”

“…16 As the last example, Závodská et al studied the effect of shot peening on fatigue strength in a low alloy steel and realised that there is an increasing positive effect on fatigue strength for crack initiation and growth due to shot peening. 17 A review of the past studies has revealed that shot peening effects on fatigue crack initiation and growth were examined by applying this surface treatment technique on the entire surface of the steel samples. However, the influence of partial peening on subsequent fatigue crack growth behaviour is yet to be investigated and compared with full surface treatment.…”