Book Review

Metallic corrosion is one of the thermodynamic certainties in life. Indeed, corrosion is such a universal principle that we all, layman or engineer, artist or scientist alike, ‘know’ (i.e. have experienced) its effects. We may even, if we cast our minds back (to school, college, that CPD course we went on 3 years ago), know some of the principles behind corrosion. For example, we know that salty water has something to do with it and that, perhaps, it is not such a great idea to bolt aluminium and copper together. However, if materials engineers are often considered as being at the tail end of engineering, then corrosion engineers are de nitely the pimple on the tail, to be ignored or scratched as the mood takes. Unfortunately, untended or abused pimples tend to fester. Many are the (maybe not so) aprocryphal tales concerning corrosion failures in practice, e.g. the architect-speci ed ‘maintenance-free’ cathedral roof in aluminium which perforated by atmospheric pitting corrosion inside a few years, the ‘marinization’ of the diesel engine which omitted the turbocharger system, resulting in its rapid destruction by damp, salt-laden air and, my favourite, the pipe-in-pipe water heating system for a subsea petroleum condensate line that was designed and installed before anyone thought about a corrosion allowance. Corrosion, therefore, is widely accepted as causing signi cant economic loss to advanced industrial economies. Surveys undertaken in the late 1970s and early 1980s in the United Kingdom, United States and Japan, all using different methodologies, came up with the remarkably consistent value of about 3–4 per cent of GNP per annum lost to corrosion. Signi cantly, these reports also emphasized that using existing knowledge it was possible to cut this loss by about one-quarter to one-half. Things have come on from those times as anyone who remembers having to stuff an oily rag into the wings of a new car in order to get more than about 2 years life out of it can testify. However, corrosion has not gone away. Recent reports from on-going research on the cost of corrosion are producing rst estimates of about 1–3 per cent of company turnover (not pro t), depending on the industry. Thus the losses, although reduced, are still important. The main problem with getting a handle on corrosion is that it necessarily involves a bit of chemistry, a subject with which many engineers are uncomfortable. Nevertheless, some general principles can be stated and incorporated into design codes where appropriate. Some of the more obvious ones relate to the coupling of dissimilar metals, yet problems of galvanic corrosion are still some the most commonly encountered. Again, there are some wonderful stories. There is one of a wealthy industrialist who insisted on the hull of his yacht being constructed from copper–nickel alloy ‘to stop corrosion and marine fouling’—an admirable idea, except that the shipyard, unfamiliar with the material, joined the plates using steel rivets. A successful launch was followed, a few days later, by a graceful sinking. Another concerns an engineering company which speci ed 316L stainless steel rising gates for a tidal barrier which were then supported by carbon steel piled piers. The stainless steel could not be coated and the cathodic protection requirement for protection of the piers was enormous. Unfortunately, there are few books available that address these issues without being either over complex or patronizing. This new volume by Roger Francis makes good use of his 25 years of engineering experience in the materials and corrosion eld. It contains a necessary, but wisely brief, overview of some of the chemical fundamentals and then follows with a logical treatment considering the most common classes of metals in turn followed by the most common environments in which corrosion problems might be expected. There is a good discussion of ow effects in pipes, valves, pumps, etc., and a relevant section on the prevention of galvanic corrosion. This essentially involves an awareness of system design and materials compatibility in a given process uid or condition. The book is well and frequently illustrated by case studies and is at its strongest when discussing marine corrosion, although there are also very useful sections on other common environments. The book is aimed at practising engineers and largely succeeds in providing a concise, readable account which has some background science and references for those who wish to follow up the subjects in more detail, but it also contains suf cient data and information to stand alone. The book would also be suitable for some students of corrosion but, in such a case, the background science needs to be supported by other more detailed texts. The cost is not out of line compared with other, similar, books and membership of NACE provides a useful 20 per cent discount. In summary, the volume succeeds in its aims, can be recommended and, frankly, should be bought and read by those working in the area.