Abstract:

The effect of the surface integrity on the bending fatigue life of 34CrNiMo6 high-strength steel is investigated using a specimen finished under various cutting conditions through fatigue test. The results show that the effect of residual stress on fatigue life is more pronounced than the effect of surface roughness and work hardening, an increase in compressive residual stress causes an increase in fatigue life. When surface roughness value of Ry is more than 10 滋m, the surface roughness influences the fatigue life significantly. The effect of work hardening on fatigue life is unfavorable. The fatigue life becomes shorter as the surface hardness becomes higher. The fatigue life of high-strength steel can be improved by applying such cutting conditions as low feed rate and small nose radius.

Key words: machinofature technique and equipment, high-strength steel, surface integrity, fatigue life