The pixel-covering method is used to research the fractal character of stress corrosion fracture so as to fit the property of gray images.

The formation and propagation mechanism of the cracks is discus - sed and the cause for the stress corrosion fracture in the brass pipe is elucidated.

The mechanism of the shat-blast enhancing technology and its eldest on improving resisfemle to fatigue and stress corrosion fracture are describe briefly in this paper.