Carbon in Solution and the Charpy Impact Performance of Medium Mn Steels

Abstract Carbon is a well known austenite stabiliser and can be used to alter the stacking fault energy stability against martensitic transformation in medium Mn steels, producing range of deformation mechanisms such as Transformation Induced Plasticity (TRIP) or combined Twinning (TWIP + TRIP) effects. However, effect C beyond quasi-static tensile behaviour less known. Therefore, two steels with 0.2 0.5 wt pct were designed produce similar fractions therefore behaviour. These processed form lamellar mixed equiaxed microstructures. The low steel had corrected Charpy impact (KV $$_{10}$$ 10 ) 320 J cm $$^{-2}$$ - 2 compared 66 high despite both having ductility over 35 pct. Interface segregation, e.g. , tramp elements, was investigated potential cause none found. Only small amount rejection from partitioning observed at interface. fracture surfaces TRIP found occur more readily Low specimen. Therefore it concluded that use promote TWIP should avoided alloy design but performance understood purely terms solution.