Austenitic cast irons may be regarded as bearing the same relation to ordinary cast irons as some of the stainless steels bear to the ordinary steels. Although more expensive, both in raw materials and manufacture, the austenitic cast irons have properties which mark them off as different from all other cast irons, particularly in their softness and ductility; high resistance to wear, erosion, corrosion and heat; non-magnetism and relatively high electrical resistance; low thermal conductivity and high thermal expansion. Their mechanical properties compare with those of a good engineering cast iron, but their softness and toughness make them readily machinable. They are readily welded. They are not susceptible to ordinary heat treatment, i.e. quenching and tempering, but nevertheless can be annealed at low temperatures with advantage. They can be cast white if required, and a simple thermal treatment such as annealing at 950 deg. C. for 30 minutes yields a metal with 2–3 per cent elongation in the cold. While the founding of these irons presents special problems, these can be overcome and the smallest castings can be, and are, successfully made in austenitic irons, down to -inch section; but if thin sections should be hard, they can be softened by the treatment given above. They melt at about 1,150 deg. C., a figure similar to that of the non-phosphoric cast irons, and have a specific gravity of 7·2–7·6. The present report is intended primarily as a guide to the engineering properties of the austenitic cast irons, in order that engineers may use them to the fullest extent justified by their properties. The data presented are drawn from authoritative sources, and a list of the papers and reports consulted is given at the end. In general, the data are those of interest to the user rather than the maker, to the engineer rather than the metallurgist.

Methods are described, by the application of which the probabilities of injury to car occupants in collisions of all types may be estimated from data on injury accidents alone, without having to make counts of accidents in which no injury had occurred. To do this, however, the velocity changes have to be known for all vehicles in the sample, so that separate probabilities of injury may be calculated for a number of successive small intervals of velocity change covering the range of velocity change in the accident sample. Proceeding in this way, sets of curves of probability of injury at various levels of injury versus velocity change may be drawn, both for overall injury, and for injury to different regions of the body. A sample calculation at one value of velocity change is given. The method is applicable to single vehicle accidents as well as to collisions, provided that there are at least two car occupants. It is anticipated that the method will be particularly valuable when applied to estimate the effectiveness of seat belts, since it will then be possible to examine how the protection given changes with severity of accident, thus pointing to where improvements are desirable. Difficulties which arise when certain analyses of injury accidents are made without introducing probability theory are discussed.

The chairman addresses the impact of future change on the life of the professional automotive engineer, external factors influencing change, the British bus industry requirements, the export bus industry requirements, process innovations and products innovations.

When one looks at the twenty-first century it is clear that the extrapolation of high technology must lead to disaster. The factors are arms escalation, increase of the gap between rich and poor countries, growth of deserts, exhaustion of easily won raw materials, especially hydrocarbons, the cumulative effects of pollution, and increasing unemployment. Necessary steps towards a stable world are for the rich countries to accept a considerable reduction in their use of resources, to provide everyone with an interesting and well paid job and to shift a steadily increasing fraction of their engineering R & D resources from weaponry to co-operative production of equipment for the poor countries.

A technique for the numerical optimization of a finite element model of a high energy rate forming machine is introduced. Both the nature of the impulsive loading and selected structural dimensions are optimized with respect to a simple measure of the noise created during a forging operation. The authors conclude that the technique could be applied to other structures or could be based on a more sophisticated noise criterion although dynamic finite element analyses demand considerable computing power.