A Short History of Corrosion

From an operator s perspective, corrosion appears to be a relentless, imavoidable, and gradual process. Pipes do rust and eventually fail, but the rust takes years to cause a failure. It is rather like cigarette smoking—clearly a deadly habit, but very slow to progress to disease. 

But this is not always the case. Corrosive failures sometimes appear suddenly. 1 have described below a few incidents from my experience to illustrate that corrosive failures can occur in a matter of hours, or even minutes, in the right (i.e., dangerous) environment. 

It is 3 00 A.M. and 1 am fast asleep. The ringing phone drags me out of bed. It is Henry Zipperian, my not-so-wonderful shift foreman. 

Twenty minutes later, I was standing underneath an 8-inch line spewing a jet of liquid isobutane. I watched it flash to a white cloud in the warm Texas night. How had this happened What had caused a sudden leak to develop on the new carbon steel line  

Strong sulfuric acid above 85 percent strength is entirely noncorrosive. As the sulfuric acid is diluted with water, it becomes exponentially more corrosive to carbon steel. Small amounts of weak sulfuric acid were carrying over into the reactor effluent line from the caustic settler. 

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