Effect of microstructure on the steel A694 F60 toughness values KV-46
ASTM A694 F60 steel belongs to HSLA steels, specifically to sub-group called Low Carbon Bainitic Steels (LCBS), which in tempered state exhibit an almost optimal combination of strength and toughness, as well as good weldability. From LCBS are manufactured forgings of flanges and fittings, which are used at low temperatures. The paper deals with the issue of considerable scattering of values KV-46 laboratory forgings from A694 F60 steel, based on fractographic and metallographic analyses supplemented to a limited extent by the EBSD method. The influence of the size of the austenitic grains, the cleavage facets and the “effective grains size” on KV-46 values were studied in detail.