Application of Shot Peening for Automotive Components

This paper presents current applications and the required considerations of Shot Peening on aluminium alloy castings, case-hardened parts and austempered ductile cast iron. Aluminium alloy castings can be improved of fatigue strength by the effect of compressive residual stress of Shot Peening. As for case-hardened parts, querched martensite in the case-hardened layer is transformed into tempered martensite and retained austenite, first into quenched martensite and then tempered martensite by plastic strain resulted. from Shot Peening. Also, it is noted that this behavior is closely related with the peening intensity, which increases the compressive residual stress and results in increased fatigue strength. In case of austempered ductile cast-iron gear, it will have increased fatigue strength at the teeth root comparable to that of case-hardened gear by the compressive residual stress generated from Shot Peening.