Rolling the same time to improve the surface roughness

Rolling the same time to improve the surface roughness of the surface layer of residual compressive stress generated can increase fatigue strength.

Figure 1 Turning and Rolling of SUS304 Roll forming machine after the residual stress distribution were compared.
Rolling can be learned after the residual compressive stress in the workpiece depth of 0.08 ~ 0.10mm to be the highest.

Figure 2 shows the same test on the internal Roll forming pressure processing of material fatigue test results. Rolling of the work piece in the direction of the compressive circumferential stress near the fatigue limit can inhibit the occurrence of cracks, the fatigue strength increased by 30%.