Influence of surface integrity on the fatigue behaviour of a hot-forged and shot-peened C70 steel component
Article dans une revue avec comité de lecture
Author
Date
2017-01-14Journal
Materials Science and Engineering: AAbstract
Hot-forging is a process commonly used in the manufacturing of automobile parts such as connecting rods. Most hot-forged components are shot-blasted after forging in order to clean off the forging scale. The shotblasting process is akin to shot-peening and greatly affects the surface integrity of the components by introducing hardening and residual stresses. This study focuses on the influence of the surface integrity on the fatigue behaviour of a hot-forged C70 steel connecting rod. Specimens were machined out of the connecting rods in order to perform fatigue testing on the forged surface. Several surfaces states, including shot-peened surfaces, were studied in order to quantify the influence of the surface integrity. A thorough characterisation of the surface integrity of the specimens was first performed. The hardness, residual stresses and microstructure gradients were analysed, and the surface of each specimen was scanned using a profilometer. The specimens show complex networks of surface defects introduced during forging, and the shot-blasting process introduces important surface residual stress and microstructure gradients. High cycle fatigue tests in plane bending were then performed on the specimens, with the surface scans helping to identify the critical defect on which crack initiation occurred. The fatigue results, presented in the form of a Kitagawa
diagram, are analysed in order to determine which surface integrity parameters are the most influential on fatigue behaviour. The forging defects have an important negative effect on fatigue strength. After shot-blasting, the fatigue strength increases considerably because of the large compressive residual stresses introduced by the shot-blasting process.
Files in this item
Related items
Showing items related by title, author, creator and subject.
-
Article dans une revue avec comité de lectureThe present study focuses on analysing and modelling the influence on fatigue behaviour of the surface of a hot-forged C70 connecting rod which undergoes a shot-blasting treatment. The shot-blasting heavily affects the ...
-
Communication avec acteThe present study focuses on analysing and modelling the influence on fatigue behaviour of the surface of a hot-forged C70 connecting rod which undergoes a shot-blasting treatment. The shot-blasting heavily affects the ...
-
Article dans une revue avec comité de lectureLa déformation introduite dans le matériau par les procédés de forgeage à froid peut être considérée comme un type de pré-déformation, appliquée avant l’utilisation en fonctionnement du composant. Cette déformation modifie ...
-
Article dans une revue avec comité de lectureCold extrusion is a process commonly used to manufacture drive train components in the automotive industry. Large plastic strains can be applied during this operation (up to 1.5) and greatly changes the mechanical properties ...
-
Communication avec acteGERIN, Benjamin; VERDU, Catherine;
MOREL, Franck;
PESSARD, Etienne (Société Française de Métallurgie et de Matériaux, 2014)
The present study focusses on analysing and modelling the influence on fatigue behaviour of the surface of a hot-forged C70 connecting rod which undergoes a shot-blasting treatment. The shot-blasting heavily affects the ...