Non-grain oriented electric sheet steel or strip obtained from a steel melt has an austenitic structure, then a mixed structure consisting of austenite and ferrite, and finally a ferritic structure over the course of cooling

摘要

Non-grain oriented electric sheet steel or strip obtained from a steel melt has an austenitic structure, then a mixed structure consisting of austenite and ferrite, and finally a ferritic structure over the course of cooling starting from a temperature of at least 1,050 deg C. The steel sheet or strip has a polarization of 1.5 T and a frequency of 50 Hz, a hysteresis loss P1.5 that is less than 4.7 W/kg, a magnetic polarization B25 equal to at least 1.60T at a magnetic field strength of 2,500 A/m, and a magnetic permeability of mu 1.5 of at least 1,500 at a frequency of 50 Hz. Non-grain oriented electric sheet steel or strip obtained from a steel melt has an austenitic structure, then a mixed structure consisting of austenite and ferrite, and finally a ferritic structure over the course of cooling starting from a temperature of at least 1,050 deg C. The steel sheet or strip has a polarization of 1.5 T and a frequency of 50 Hz, a hysteresis loss P1.5 that is less than 4.7 W/kg, a magnetic polarization B25 equal to at least 1.60T at a magnetic field strength of 2,500 A/m, and a magnetic permeability of mu 1.5 of at least 1,500 at a frequency of 50 Hz. The steel melt contains (in wt.%) <= 1.8 silicon (Si), 1 aluminium (Al), <= 0.02 carbon (C), 0.5 magnesium (Mg), <= 0.03 tin (Sn), <= 0.1 antimony (Sb), <= 0.1 phosphorus (P), 0.02 sulphur (S), <= 0.01 titanium (Ti), <= 0.01 nitrogen (N), <= 0.01 O, <= 0.01 boron (B) and a balance of Fe. An Independent claim is also included for a for the production of the non-grain oriented electric sheet steel or strip. Preferably the hysteresis loss P1.5 is less than 4.5 W/kg and the magnetic polarization B25 is a maximum of 1.65T.