Fretting Corrosion Property of Zr-4 alloy in Na2 SO4 Solution

Using fretting wear abrasion testing machine, fretting wear and fretting corrosion test of the Zr-4 alloy against Al2O3 placed respectively in air, pure water and Na2SO4 solution was carried out. The wear volume was measured with 3D measuring instrument and the relationship between the fresh surface fretting wear produces and lost surface was evaluated with the potential pulse method. The result shows that the fresh surfacing area was smaller than abrasion mark area, and it was bigger than actual contact area. The wear of Zr-4 alloy against Al2O3 in Na2SO4 solution was ten times higher than that in air and pure water, but its coefficient of friction was smaller. The wear of Zr-4 alloy against Al2O3 in pure water was equal to the numeric value of the Zr-4 alloy against Al2O3 in Na2 SO4 solution given the -2000 mv potential. When Zr-4 alloy was in corrosion environment, the wear increased in proportion to the increase of the potential, and the fretting wear and fretting corrosion resulted mainly from electrochemical action.