Study on stress corrosion cracking sensitivity of Al-Zn-Mg-Zr alloy containing Sc

The stress corrosion cracking(SCC) susceptibility of Al-Zn-Mg-Zr alloy containing Sc with T6 and T73 temper has been investigated by slow strain rate tension(SSRT) tests in air and in 3.5%(wt) NaCl solution respectively.The effect of heat treatment and strain rate on SCC has been studied by scanning electron microscope.The results show that under the same heat-treatment condition,the stress corrosion cracking susceptibility of the alloy is higher while the alloy being deformed with strain rate of 1.33×10-6 s-1 than that alloy with strain rate of 6.66×10-6 s-1;and at the same strain rate,the stress corrosion cracking susceptibility of the alloy with T6 temper is higher than that alloy with T73 temper.That means that the stress corrosion resistance of the alloy with T73 temper is better than that alloy with T6 temper.