However, the quantitative analysis of such microstructures and the effect of the sample preparation are very important for the further study of the steel.
As a result, these steels often have a complex microstructure with ferrite and martensite, which have relatively similar crystal structures, making it very difficult to analyse. A few carbides were detected at special CSL boundaries, Σ11, Σ25b, Σ33с Σ41с.Ībstract: Sample preparation of metastable austenitic-ferritic steels can have a significant effect on the apparent microstructure due to the transformation of austenite to martensite ( γ - α'). Carbide almost did not precipitate at low-angle and special CSL Σ3 boundaries. It has been shown that under martensite tempering M 23C 6 precipitation was mainly at high-angle intergranular boundaries. In the structure two types of carbide precipitates were observed: large MC along the boundaries of former austenite grains, and dispersed M 23C 6 predominantly along the boundaries in martensite packages. This spectrum, resulted from austenite transformation by shear mechanism according to orientation relationships (OR), intermediate between Kurdjumov-Sachs (K-S) and Nishiyama-Wassermann (N-W). High-angle boundary spectrum with the most prominent coincidence site lattice (CSL) boundaries, Σ3, Σ11, Σ25b, Σ33с Σ41с, is typical for martensite. The steel structure consisted of large grains of high-temperature ferrite (~ 15%), without visible mesostructured, and martensite packages with a great number of low-angle boundaries. Abstract: Different types of carbide phases and regions of their precipitation in tempered martensite of austenitic steel have been investigated with orientation microscopy (EBSD) and electron microprobe analysis.
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