One particular type of corrosion is crevice or pitting corrosion. The corrosion takes place not in broad areas, but in small cracks, or pits that form as a result of a low availability of oxygen or high concentrations of anions, such as chloride, which can prevent a surface from forming a passive film. These pits can continue to grow even if the offending species is removed or oxygen is restored because the environment within the pit or crevice will be different than the remainder of the surface. These pits or crevices can result in small, localized stress concentrations that can propagate cracks, leading to component failure.