Failure Analysis: Q7

In term of design, describe or explain the methods to control corrosion failure

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i) Allow for the penetration action of corrosion along with the mechanical strength requirements when determining the appropriate metal thickness

ii) Weld rather than rivet containers to reduce crevice corrosion. If rivets are used, choose a rivet material that is cathodic to the materials being joined.

iii) If possible, use galvanically similar metals for the entire structure. Avoid dissimilar metals that can cause galvanic corrosion. If galvanically dissimilar metals are bolted together, separate them with nonmetallic gaskets and washers.

iv) Avoid excessive stress and stress concentrations in corrosive environments to prevent stress-corrosion cracking, especially when using susceptible materials such as stainless steels and brasses.

v) Avoid sharp bends in piping systems to prevent erosion corrosion.

vi) Design tanks and other containers for easy draining and cleaning.

vii) Design systems for easy removal and replacement of parts that are expected to fail in service, such as pumps in chemical plants.

viii) Design heating systems such that hot spots do not occur.