It has occurred in thick aluminum alloy wing skin countersinks, particularly where steel fasteners are involved, and on extrusions and forgings.

• 这种锈蚀腐蚀曾经发生在厚的铝合金主翼蒙皮沉头凹槽中，特别是有钢质的扣件，以及在挤压件和锻造件上。