Images obtained by high-resolution X-ray tomography are used to show experimentally the three-dimensional character of short fatigue cracks in a cast aluminium alloy. The pores present in this alloy are preferred initiation sites for fatigue cracks, but no correlation can be established with the three-dimensional size of the pores. A strong interaction between fatigue cracks and grain boundaries is clearly shown, both at the surface and in the bulk, using post mortem 3D observations as well as in situ observations.

During the last decade, CPM developed new diagnosis techniques to evaluate more precisely coke oven battery ageing. Among them, the Videofil machine was specially devoted to the inspection of the hot refractory brickwork of coke oven chambers and heating flues. Since the first machine was put into operation, significant improvements have been performed and the last generation of Videofil machine is fully automated, more efficient, more reliable and easier to use. This machine is extensively used in coke plants, but also in the whole steel industry. It contributes to extend the plant service life, to decrease the maintenance costs and to increase the plant availability.

Sharp increase in coke prices and huge investments in new coke plants in China characterize the present situation. In Europe, revamps of batteries are typical, but also a large new coke plant went on stream at ThyssenKrupp in Schwelgern. The article examines the situation in detail and describes major investments in Europe and China.

The determination of residual stresses in coatings generally goes with the simultaneous determination of their elasticity constants. The main experimental methods used for that purpose are briefly reviewed and their advantages and limitations discussed: mechanical tests on self-bearing layers or on coated substrates, indirect physical methods.

Dislocations produced during plastic deformation tend to gather in well defined patterns. Both the shape and the structuring degree of these clusters depend on material parameters and on loading conditions. The present work analyzes these relations and classifies the observations in a schematic structural map. While a strong correlation exists between dislocation patterns and mechanical behaviours, it is shown that there is no direct effect of the substructure on either the stress level or the work-hardening rate of the material.