Galvanic effects on cavitation damage for 1Cr13 stainless steel

• 作 者: Dongbai Sun Xia Bai Hongying Y
• 机 构: UNDP-Beijing Corrosion and Protection Center
• 出 处: 北京科技大学学报
• 发表日期: 2004年期
• 关键词: cavitation damage galvanic effect area ratio mass loss

Based on the electric-spark principle, a new kind of cavitation damage testing apparatus was designed, which could produce the bubble. Bubbles collapsed and acted on a small surface area of the alloy surface, so an intensive electrochemical inhomoge nous state would be induced and lead to the existence of surface galvanic effect on the alloy. The galvanic effect of 1Cr13 SS during cavitation damage has been quantitatively investigated in NaCl solution. The results show that intensive galvanic effect of 1Crl3 SS during cavitation damage appears the potential of the damaged area shifting negatively with the bubble collapse and simultaneously the galvanic current generates. The mass loss of alloy due to cavitation increases with the bubble quantity, and increases with the in creasing of Cl- content. And both the total mass loss and the mass loss due to galvanic corrosion increase linearly with the area ratio of cavitation damaged to undamaged area. Such surface galvanic effects speed up the dissolution rate of the alloy, which, in turn, accelerates the mechanical damage, and aggravates the mass loss of the alloy. It has been further confirmed that the mass loss due to the surface galvanic effect can be decreased by catholic protection.