Download or read book The Application of Transmission Electron Microscopy to the Study of a Low-Carbon Steel written by PR. Howell and published by . This book was released on 1993 with total page 13 pages. Available in PDF, EPUB and Kindle. Book excerpt: Transmission electron microscopy (TEM) together with scanning electron microscopy (SEM) and optical microscopy have been employed to analyze the microstructures that develop in a copper-containing, low-carbon (0.04% by weight) HSLA-100 alloy. Specifically, the martensitic microstructures that develop in the simulated, coarse-grained heat-affected zones (HAZs) have been examined and compared with those that develop in the base plate during conventional quenching from the austenitic phase field. It has been shown that the lath martensitic packet size is increased dramatically in the HAZ as compared with the base plate. In addition, considerably more retained austenite is found in the HAZ. No evidence for the so-called granular bainite microconstituent has been found in either material. However, for cooling rates somewhat less than that experienced in the coarse-grained HAZ, a microconstituent that we term granular ferrite has been documented.