The following comments were provided during the survey on Human Factor in corrosion failures. They have been organized by corrosion experience levels of the participants.
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No comments were left by the rookies!
Unfortunately what we see in Australia and South East Asia from my experience is a vast gap in the understanding of the different levels of expertise involved with the design, construction and operation/maintenance of a facility. While there are many corrosion engineers about, very few design companies see corrosion as an issue, mainly due to the fact that where competitive bids are submitted, *generally* it is the cost at the bottom of the form that impresses people, not the fact that the client will not have increased maintenance costs. Unfortunately, until this mental attitude is corrected, it is very hard to change the way people do their business. (Which is okay for me, I make my money fixing other people's mistakes)
I specialize in corrosion of non-ferrous metals, particularly related to potable water systems. 25-30 years ago the majority of failures were associated with material and manufacturing defects. Now the failures are almost entirely associated with either poor design, installation or operation practices.
I would say 60% could be prevented if the corrosion literature would be studied; further 30% could be prevented if corrosion tests or corrosion institutes would be contacted..
Fifteen years +
Bean counters tend to take the cheap way out. Too often those in charge allow the applicator contractor to not meet the specification.
Hindsight is a wonderful thing. In my field of corrosion in concrete we only really understood the problems of chloride and carbonation attack in the last 10 years but of course most buildings and civil engineering structures last much longer than 10 yrs. However, even our present codes do not require adequate durability for reinforced concrete structures in saline environments.
There is a total lack of any accounting practice that includes cost of corrosion in a standard business fashion. The protect versus replace decision is made more often based on aesthetics than cost or safety. This decision is often made by untrained personnel who may unwittingly choose the wrong materials.
I agree that over 90 percent of corrosion failures could have been greatly delayed by some measures. (materials selection, coatings, cathodic protection, inhibitors/treatment). I would also state that 60% to 70% are designed to fail in a certain # of years, usually 20 or 30. Unfortunately, most of these don't make it. Most people (in business) consider the economics to favor corrosion, not corrosion control.
The problem is related to the turnover of engineering staff, and to constant re-engineering in plants, as young graduates are poorly trained in corrosion engineering and have to learn it by "osmosis" on the job. Then they get promoted and move on, to management! The next new graduate has to start all over again and learn it all from scratch. It is good business for corrosion consultants though and I guess that is the way the world is going with more and more out-sourcing of specialist work.
Design and startup are the key times, and any efforts at controlling corrosion during those phases are sporadic and usually poorly done.
While corrosion has nothing but negative aspects from most points of view, money spent to enable a corrosion engineer to control corrosion will be returned many fold and will represent one of the most profitable investments that can be made.
There is a great deal of unpredictable situations in real life and also the lack of the "uncorrodible" material that to my experience do not allow to go over the 75% (human error), marked above.
Like accidents virtually all corrosion damage is preventable, if the proper design to prevent it occurs, and the follow up maintenance of the design is properly executed. Easy to say, but difficult to accomplish. It means that everyone involved does all that they are supposed to do at the proper interval. Obstacles are: commitment (laziness), funds, time and knowledge. Roughly 90% of the engineers that come out of college have no formal training in corrosion prevention, nor has a major emphasis been placed upon its effect on the environment, economy nor quality of life. I believe that knowledge is the key and its effect on everything else.
Corrosion is inevitable, but human intervention can minimize the impact on corrosion on the function and safety of a system for an extended period. Corrosion control measures, including materials selection, coatings, cathodic protection, inhibitors, etc. can be used to balance system (and operating) costs with system life and performance. These are human (engineering) actions. If "corrosion damage" above is interpreted as "corrosion causing unforeseeable damage to system resulting in economic loss, environmental damage, loss of life or injury", then humans are responsible 100% of the time.
Of course "It all depends!" If the standard design practice is used, that is neither the designer nor the user has any idea of what is going on, or cares, then probably well over 90% of the corrosion could be prevented. If the designer is knowledgeable and, preferably, uses the services of a system specific corrosion expert, then the probability drops. In part because it has been decided that economics will permit some corrosion and risk of failure, and in part because someone down the line will blindside the designer and use the system for some other purpose.
I believe that the most expensive general error is that of forgetting about small amounts of chlorides in aqueous media (especially acids) of water in organic media and the possibility that bacteria could grow in the "soup" enclosed in the plant. The answer is probably not found in consultants, but in engineers getting short courses and refreshers in corrosion as part of a life-long learning process.
After over 40 years in the field, I have determined that most corrosion failures should have been predicted; could have been prevented; and failed like they did. The inexperienced engineer, not properly trained, make decisions that lead to these failures. IF proper consultation with corrosion specialists had occurred, then most of the failures would not have occurred.
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