MICROSTRUCTURE CHARACTERIZATION OF GOES AFTER HOT ROLLING AND COLD ROLLING plus DECARBURIZATION ANNEALING

The sharpness of the final Goss texture in GOES is significantly affected by structural inheritance during the manufacturing process. This paper deals with results of detailed microstructural investigations on strips of GOES after the first two steps of the production process: hot rolling and cold rolling + decarburization annealing. Microstructural characterization of samples was carried out using light metallography, scanning electron microscopy combined with electron backscattered diffraction (EBSD) and transmission electron microscopy. The attention has been paid to texture evaluation and minor phase evolution. In the hot rolled state the ferrite grain size reached several tens of micrometres, some grains with the orientation close to the Goss orientation were scattered across the thickness of the strips. Cold rolling + decarburization annealing resulted in a significant refinement of ferritic grains across the strip thickness. EBSD results manifested the effect of structural inheritance during cold rolling. Intensive precipitation processes took place during decarburization annealing. Most precipitates were nitrides (mainly AlN). A small addition of copper in the GOES investigated affected stability and distribution of sulphides during processing of strips. The typical size of AlN particles was several tens of nanometres.