マイクロショットピーニングによるインコネル合金の疲労改善

抄録

The improvement of fatigue life in inconel alloy by microshot peening was investigated. Shot peening is a widely used surface treatment method for improving fatigue life. This process imparts compressive residual stresses on the surface, thus improving the fatigue life of the machine parts. To reduce the surface roughness, the peening treatment with fine particles attracts attention. The size of the particle is very small and it is normal a one-tenth. In the peening process, the equipment were used an air-type machine. The microshot used were high-carbon cast steel and high hardness steel with an average diameter of 0.1 mm. The surface hardness data showed that work hardening extended deeper than the mean diameter of the media. In addition, when the workpiece was peened by high hardness steel powders, the surface hardness increased. The rotary bending fatigue tests were carried at a frequency of 3150 cycles/min. Improvement of the fatigue strength was observed by microshot peening. The higher effect was found in the peening by using high hard steel powders, because a work-hardened layer was formed deeper in the material.