Effect of the Blasting Angle on the Amount of the Residual Grit on Blasted Substrates

The residual grit weight and the penetration depth of the embedded grit were investigated by dissolution of the blasted substrate with a mixed acid solution. A carbon steel substrate was blasted by white alumina grit (WA #30). The blasting angle varied from 30° to 90°. The residual grit amount and the penetration depth increased with increasing blasting angle. The residual grit amount was 2-12 g/m², and the penetration depth was 26-34 µm. When the blasting angle increased from 30° to 90°, the increase ratio of the residual grit amount was 6.0, although the increase ratio of perpendicular component of impact energy by blasting was 2.0. To reduce the residual grit amount, a decrease of blasting angle is more effective than the decrease of grit mass. For the reduction of the penetration depth of the embedded grit, the blasting angle effect is small.