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The aim of this paper is to study the effect of heat treatment temperature and time on the corrosion behavior of ductile iron in 0.5 M NaCl and 0.5 M H₂SO₄.

Ductile iron samples of known composition were austenized at temperatures 800°C and 850°C, and austempered at 300°C and 350°C for periods of 30, 45 and 60 min to convert them to austempered ductile iron (ADI). The corrosion behavior of these ADI samples in 0.5 M NaCl and H₂SO₄ was measured using the conventional weight loss method. The metallographic examination of the samples was carried out to study the morphology of their corroded surfaces.

Ductile iron is susceptible to corrosion in both acidic and chloride media, while attack by acid media is mainly at the grain boundaries, that from the chloride is pitting. The corrosion behavior of the material is affected by the compositional structures of the materials as well as the austempering temperature and time it was subjected to.

Ductile iron has the potential to replace costlier materials in many engineering and structural applications.

The results revealed that the corrosion of ADI in both acidic and chloride media were strongly dependent on the structure of the material, which in turn was affected by the austempering temperature and time.

Service life or consumption rate of any reusable blast cleaning or shot peening abrasive is dependent upon its toughness and ability to withstand repeated impact. In cast steel abrasives, both structural and physical factors influence this. Isothermal, specifically austempering, heat treatment techniques are well established processes which can offer superior toughness and impact characteristics to both steels and irons. IsoShot is a new, bainitic, cast steel shot produced using an austempering technique.

THE MAIN INTEREST of the ancients in steel was the production of weapons, and their method of quenching was simple and effective. They ran the red hot blade through the heart of the strongest slave they could find, believing that the strength of the dying slave entered the steel.

WEAR is one of the major ways by which a material part ceases to be useful, others are corrosion, obsolescence and breakage. It is the consequence of relative motion and in industrial plant and equipment it has always been accepted as inevitable that it should lead to heavy expenditure for maintenance and replacement. Historically, wear is a well established fact, yet our knowledge of the technology is extremely limited. It has become a way of life that we compensate for wear when it no longer can be tolerated, yet need this be so? This article examines the problem, and primarily from the unlubricated point of view, describes the various types of wear and the way material selection or modification can be used to limit wear.

Automation hand‐in‐hand with a determined management and a dedicated workforce have helped Tl Apollo turn round its golf shaft business. Brian Rooks visited the Oldbury factory to find out how.

AT THE Design Engineering Conference, organised by The American Society of Mechanical Engineers at Chicago in May, several papers were very much concerned with the subject of Wear and methods of promoting wear resistance —i.e. both as regards materials and management. As E. F. Finkin (Mechanical Technology Inc.) said: Almost all theoretical and experimental knowledge of wear processes was developed after 1950, so it is a rather young science—one might say that before 1950 it was like the weather in that everyone talked about it but no one studied it. Mr. Finkin went on “Today a great body of information exists but is almost completely ignored by United States industry……Three foreign governments, U.K., USSR and E. Germany, have come to realise the importance of the problem and are attempting to do something about it”.

Roofing system needs no vapour barrier. Savings in construction and maintenance costs and resistance to wind uplift and corrosion are the benefits of a new insulation system for steel roofs.

In his inaugural lecture at Imperial College, Professor J. G. Ball pointed to the tendency of metallurgy to become a scientific discipline of logical inference, making teaching centred on plant skills, and the parrot‐learning of facts and alloy specifications quite out of date. The principles and practice of teaching with special reference to metallurgy have not received the attention accorded to allied subjects such as chemistry. The purpose of this article is to provoke thought, criticism and free discussion among those engaged in the dissemination of metallurgical knowledge.

The paper presents results of a pilot project on technological innovation of main flexible components for automotive suspension systems, that are coil springs and stabilizer bars. Current technology has been described and related problems have been outlined. In order to fulfil features such as compactness, lightness and environmentally conscious design, solutions based on new forms, materials and manufacturing processes have been proposed. Improvements in weights, dimensions, noiselessness, corrosion and fatigue strength, environmental effects, have been all assessed, keeping a quite low project cost (around $3 million).

The purpose of this paper is to evaluate the effects of medium carbon steel microstructure on the tensile strength and fatigue crack growth (FCG) behavior.

To achieve this aim, four different heat treatment methods (normalizing, quenching, tempering at 300°C and tempering at 600°C) were considered. Microstructural evolution was investigated by scanning electron microscopy. FCG rate tests were conducted on the resultant microstructures with compact tension specimens at room temperature by a standard testing method.

The results show that the normalized microstructure had the largest number of cycles to failure, indicating a high fatigue resistance, followed by the as received, tempered at 600°C, tempered at 300°C and quenched microstructure.

The paper shows the influence of the microstructure on the fatigue-propagation behavior with the definition of the Paris parameters of each heat treatment condition.