Powder-Metallurgical Production, Structural Conditions and Properties of the Super-alloyed Corrosion Resistant Plastic Mould Steel M390 ISOMATRIX

摘要

The M390 ISOMATRIX plastic mould steel, produced by powder metallurgical methods, was developed for tools exposed to combined corrosion and wear stresses. Thanks to optimized chemical compositon this steel features a martensitic structure with finely dispersed M_7C_3 and MC carbides. The well balanced carbon/chromium ratio ensures operating hardness values of more than 60 HRC coupled with adequately high corrosion resistance. The corrosion resistance behaviour can be influenced, within a wide range, by heat treatment. On the basis of TEM tests and small-angle neutron scattering examinations, it was possible to correlate the relevant microstructure conditions to the various types of corrosion behaviour and thus to determine optimum heat treatment processes for practical operation.