Metal loss tools

Metal loss tools are used to detect defects that have resulted in wall thinning in a pipeline. They can discriminate to some extent between manufacturing defects, corrosion defects and mechanical damage. There are two main typ>es of tools ... 

Kiefner, J. F., Hyatt, R. W. and Eiber, R. J., Metal Loss, Crack Detection Tools Targeted , ibid., 69-71, 24 April (1989)... 

Existence of advanced tools that makes it possible to deal satisfactorily with most of the objectives required fi om intelligent pigging operations, at least for metal loss corrosion... 

A material and component life assessment concept, that is traditionally based on the theory of creep only, has to be established for the new fuel types (bio-based wood chips, straw, peat, recycled waste, etc.). The OPTICORR approach aims at development of modelling tools for high-temperature active oxidation and corrosion to predict metal loss as a function of the service conditions and gas compositions. The development is based on selected cases and corresponding experimental studies. 

The advantages of the modern form of this method are that many alloys that cannot be conveniently drawn into wire form can be used in the process, that the hand tool contains no moving parts, and that high outputs can be obtained. The disadvantage of the powder system is that it is not very suitable for high-melting-point metals, and the losses are higher than with wire, because not all the particles are melted. 

The wear and subsequent failure of a cutting tool is a complex mechanism that usually involves a number of physical and chemical phenomena. Temperatures at the tool/workpiece interface (cutting edge) may reach up to 1200°C in a very short period of time. This creates a pronounced thermal shock and promotes oxidation of the tool surface and the diffusion of metallic constituents of the tool into the chip with a resulting loss of tool strength. 

The first EELS experiments were reported by Propst and Piper in 1967 and concerned the adsorption of H2, N2, CO, H20 on the (100) surface of tungsten [49]. Ibach studied the energy losses of electrons to phonons in ZnO surfaces around 1970 [50] and continued to develop the technique for studying adsorbates on metal surfaces [51,52]. In the 1980s EELS grew further into an extremely important and generally accepted tool in surface science. 

The Fig. 8 a shows tools for reshaping crucibles after use. During physical and chemical treatment crucibles are often deformed, especially noble metal. This results in a loss of good heat transfer to the thermocouple which records the temperature during experiments. Plastic tools are available for reshaping crucibles. 

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