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Developments in higher temperature exchangers and other applications, require high strength as well as oxidation resistance at very high temperatures. In order to meet such requirements, Dour Metal has developed the ODM a new range of oxide dispersion strengthened (ODS) iron based materials. Compositional and thermomechanical manipulations can be used to develop the structure enabling the service temperature to be increased up to about 1200°C. Typical rupture strengths are presented for temperatures ranging from 900 to 1100°C. Data on oxidation and corrosion properties of various compositions are also presented. The emphasis is given to alloy ODM 751 on which most recent work has been performed. The composition of the alloy is 16.5% Cr‐4.5% Al‐0.6% Ti‐1.5% Mo‐0.5% Y2O3‐bal Fe and provides the best compromise between strength, formability and oxidation resistance. Measurements of longitudinal creep at 1100°C to 1200°C on ODM 751 tubes show the outstanding properties of the alloy in this range of temperatures.

Last month we published abstracts and summaries of some of the papers presented at the Congress, which was held at the Imperial College of Science and Technology from April 10–15 under the auspices of the International Union of Pure and Applied Chemistry. In this issue we publish further abstracts and summaries together with illustrations of many of the corrosionists attending and photographs of some of the many visits which were arranged to works and laboratories. The Congress attracted over 800 delegates.

Due to the special service environment of superalloys, this paper aims to obtain effects of temperature and Ti addition on high temperature oxidation behavior of Co-Al-W-B alloys.

Isothermal oxidation experiment of Co-Al-W-based alloys were carried out at 800°C, 900°C and 1000°C for different times (3, 5, 10, 20, 50 and 100 h) referring to the method of HB5258-2000. Oxidation weight gain curves and oxidation products were detected.

The results showed that the average oxidation rates of Co-Al-W-B alloy at 800 °C and 900 °C were 0.489 g·m⁻²·h⁻¹ and 0.888 g·m⁻²·h⁻¹, respectively, which belonged to an antioxidant grade. However, the average oxidation rate at 1000 °C was 2.068 g m⁻²·h⁻¹, belonging to the secondary oxidation resistance class. In the alloy with Ti addition, dense Ti oxides film were formed at the early oxidation stage and then gradually diffused later, which can increase the oxidation resistance of the alloys to some extent. By analyzing the oxidation products of Co-Al-W-B alloy, it was found that a dense Al₂O₃ layer could be formed when the alloy was oxidized at 800°C. The continuous Al₂O₃ layer would prevent the oxygen from further spreading and make the alloy into the stable oxidation stage. However, only a non-dense Al₂O₃ layer were observed with 900°C oxidation.

It can provide references for the composition design, preparation process optimization and protective coating selection of the γ′ phase strengthened cobalt-base superalloys.