Practical Aspects of Application of Shot Peening to Improve the Fatigue Behaviour of Metals and Structural Components

Author:  Wohlfahrt, H.
Source:  Conf Proc: ICSP-3, (p.563-584)
Doc ID:  1987069
Year of Publication:  1987
Abstract:  
The aims of this paper are to describe the favourable effects of shot peening which can be useful for the improvement of the fatigue behaviour in practical applications and to direct attention to the special peening conditions, which have to be obeyed as well as to indicate limitations in improving the fatigue behaviour by shot peening. In order to fulfil these purposes it is necessary to classify structural components in different categories. Of primary importance for the classification is the kind of the material and the state of the material of the structural components. Therefore this aspect shall serve as clue in the following. Other aspects concerning the effectiveness of shot peening for structural components of different shape and dimensions or under different kinds of loading have to be taken into consideration separately for different materials and material states. Especially results on the effectiveness of shot peening in notches respectively of notched parts can not simply be transferred from one state of a material to the other. Also not simply transferable from one material to the other are results about the influence of shot peening on the fatigue behaviour under different loading modes as loading with constant or with variable amplitudes, loading with or without mean stresses or tension-compression-, bending- or torsional loading. Such results have also to be discussed separately in the different sections. Therefore in the following - after a short summary of principally important facts concerning the effects of shot peening - the experimental results about shot peen induced improvements of the fatigue behaviour are reported in different sections for different materials. For steels the different strength or hardness levels of the material can be represented by different structural components. Welded joints of steels are typical components in a relatively soft, normalized state or in a quenched and tempered state of the material. Other typical structural components in a quenched and tempered state are forgings. Gears and springs are typical representatives for structural components in a relatively hard materials' state - at least in surface layers - which are often or mostly shot peened. Concerning A1 and Ti alloys it shall be discussed how significant important results from tests with specimens are for structural components. Finally some remarks shall be made about the effect of shot peening of sintered materials.