Steel Steels, Microscopic Structure

Using the previous equations we can derive the microscopic structure (/. e., the kinds of defects and their concentrations) from the experimentally determined lifetimes and intensities if the problem is homogeneous. This premise, however, does not hold for RPV steels completely. In inhomogeneous problems, the diffusion of positrons from the various implantation sites to the trapping centres must also be considered [125,130]. However, the mathematical difficulties associated with the corresponding diffusion-trapping model (DTM) [73] have so far prevented exact solutions from being obtained for all but the simplest problems [116,117], Thus, it is impossible to qualitatively analyse the very detailed experimental results obtained with a pulsed positron beam. 

Many other atom-probe analyses of different phases in different types of steels exist as steels are one of the most important materials. It is possible to investigate how the magnetic properties of alloys are correlated to the microstructures of different phases in the alloys.57,58,59 The chemical contents, growth process and structures of metallic carbides in different alloy steels have been studied with the field ion microscope and the atom-probe field ion microscope.60 61 62 63 We refer the reader to some of the original papers published on these subjects. 

Example of the obtained acoustic microscope image is represented on Fig. 1. It demonstrated with 220x magnification, the structure of steel BHC-2M. 

Morgan RJ, Pruneda CO, Steele WJ (1983) The relationship between the physical structure and the microscopic deftamation and failure process of poly(p-phenylene terephthalamide) fibers. J. Polymer Sci., Polymer Phys. Ed. 21 MSI... 

The benefit of the atomic force microscope is that it ean define the surface of eeUs at moleeular resolution, showing the mechanisms in more detail. For example, red blood cells were collected in EDTA K2 and smeared across a steel dise. Fixing of the cells was achieved with glutaraldehyde. The cells were dried and seanned in the AFM. At high resolution, down to 5 mn, structures were... 

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