| Abstrakt: |
Modern high-strength cast irons with spherical graphite have strength comparable with that of alloyed steel. However, the replacement of steel by cast iron when manufacturing critical duty products is restrained by the brittleness of cast iron: the higher is strength, the lower is plasticity. Now it is possible to overcome this law: a new material (cast iron) MONICA named after its alloying additives molybdenum (Mo), nickel (Ni) and copper (Cu) was created, which in contrast loses its brittleness with increasing strength. A new (unexpected) regularity has been established: with the increase in strength of MONICA, its plasticity also increases. This was also confirmed by the results of tests on fracture toughness, rolling and mechanical fatigue. Specific mechanical and service properties of MONICA were analysed in comparison with traditional steels and known high-strength cast irons with spherical graphite (ADI). These properties were confirmed by operational tests of high-loaded full-scale parts: knives of cutting devices of high-performance forage harvesters, heavy railway rails, large gear wheels. |
