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Stress corrosion cracking at the weld areas in the interior of blast furnace stoves has become a world wide problem which has been accentuated by the higher operating temperatures and pressures now used. This paper describes the work carried out to evaluate various protective coatings proposed for application to the interior of the stove shell plates to prevent the stress corrosion. A heat and chemical resistant polyurethane primer‐pitch polyurethane top coat has given superior results to all coatings tested, particularly when applied over a hot sprayed ceramic.

Corrosion failures due to condensing flue gases containing H₂O, SO₃, NO_x and HCl still occur more often than might be expected. The corrosion failures can be of several types: general corrosion, pitting attack and stress corrosion cracking (SCC). The chemistry of condensing gases is discussed, and some examples of corrosion in large‐scale installations are presented, including blast stoves for steel production, heat recovery steam generators, and waste incineration boilers. The use of thermal insulation inside boiler casings can result in nitrate SCC when the flue gas contains high concentrations of NO_x. Nitric acid from flue gas can react with carbon steel and insulation material forming ammonium nitrate and calcium nitrate. Both materials have hygroscopic properties and are very corrosive, even above the water dewpoint of the gases.

Development Latices EL54 and EL55 from Revertex Ltd., Temple Fields, Harlow, Essex, are Carboxylated styrene ‐ butadiene molymer latices. They are said to represent a completely new generation of paper and board coating latices, specially designed for the following properties: Very low residual odour. Excellent mechanical stability. Excellent chemical stability (resistance to multivalent cations). FDA and BGA compliance for contact with dry foods.

The construction industry relies increasingly on profits generated from high utilisation of mechanisation. Interruption of this mechanical supply not only incurs the “tangible” costs of labour, replacement parts and consumables, but also the less tangible costs of delays to contract, possible loss of client goodwill and ultimately, loss of profit. Cumulative costs associated with plant breakdown are therefore significant. Predictive maintenance (PM) techniques have evolved to keep a check on mechanical health, by generating information on machine condition. Such data allow just in time maintenance to be conducted. However, recent developments have witnessed an increased interest in determining “root cause” of failure as opposed to monitoring the time to breakdown once the wear process has begun. This paper reviews condition based monitoring (CBM) technologies and introduces the evolving concept of root cause analysis. Both these could have particular relevance to construction plant and equipment. In summary, the paper presents initial findings of ongoing research, which is the development of a model for predicting construction plant and equipment breakdown.

The purpose of this paper is to propose an integrative approach for improving failure modes and effects analysis (FMEA).

An extensive literature review on FMEA has been performed. Then, an integrative approach has been proposed based on literature review. The proposed approach is an integration of FMEA and quality function deployment (QFD). The proposed approach includes a two-phase QFD. In the first phase, failure modes are prioritized based on failure effects and in the second phase, failure causes are prioritized based on failure modes. The proposed approach has been examined in a case example at the blast furnace operation of a steel-manufacturing company.

Results of the case example indicated that stove shell crack in hot blast blower, pump failure in cooling water supply pump and bleeder valves failed to operate are the first three important failure modes. In addition, fire and explosion are the most important failure effects. Also, improper maintenance, over pressure and excess temperature are the most important failure causes. Findings also indicated that the proposed approach with the consideration of interrelationships among failure effects, failure mode and failure causes can influence and adjust risk priority number (RPN) in FMEA.

As manufacturing departments are mostly dealing with failure effects and modes of machinery and maintenance departments are mostly dealing with causes of failures, the proposed model can support better coordination and integration between the two departments. Such support seems to be more important in firms with continuous production lines wherein line interruption influences response to customers more seriously. A wide range of future study opportunities indicates the attractiveness and contribution of the subject to the knowledge of FMEA.

Although the literature indicates that in most of studies the outcomes of QFD were entered into FMEA and in some studies the RPN of FMEA was entered into QFD as importance rating, the proposed approach is a true type of the so-called “integration of FMEA and QFD” because the three main elements of FMEA formed the structure of QFD. In other words, the proposed approach can be considered as an innovation in the FMEA structure, not as a data provider prior to it or a data receiver after it.

Over the last few years a number of gas turbines have been installed in steelworks for driving the blast blower of the blast‐furnace and/or the generation of electricity for the steelworks. Some of these have now been running for several thousand hours and have undergone acceptance and other tests which have disclosed widely varying amounts of corrosion and incrustation.

The first part of this article appeared in our August issue and dealt with Lubrication Organisation, storing and handling at The Steel Company of Wales. Since writing this the author informs us that a Supervisor has now been appointed at the Margam plant and he will build up a similar organisation to that now operating at the Abbey Works.

Geigy Co. Ltd. Stand 75. Diversified application of benzotriazole as a corrosion inhibitor specifically for copper and its alloys is the main theme of Geigy's stand.

Coatings Solve Descaling Problems. Formidable problems of oxidation and scale formation are encountered in the heat treatment of creep‐resistant and heat‐resistant metals which demand lengthy descaling operations after treatment, or the use of controlled‐atmosphere or vacuum furnaces. Within the last two years, however, Rolls‐Royce Ltd. have developed protective coatings which, as a result of subsequent co‐operation with F. W. Berk & Co. Ltd., are available under the name of Berkatekt for protecting the metals from oxidation, intergranular corrosion and decarburisation during treatment.

This article describes work carried out in UKAEA laboratories to examine the possibility of using protective coatings on cadmium plate—such as that used to protect mild steel—in order to prevent or minimise corrosion due to hostile organic vapours. The degree of attack by vapours of acetic, formic, butyric and propionic acids and formaldehyde on cadmium has been determined and it has been found that attack can be eliminated in many cases by the application of a chlorinated‐rubber lacquer to the metal. A pretreatment primer of the two‐pack etch‐primer type is considered essential for good protection. The protection provided by nine coatings over three pretreatments is described in detail.