Patent ID: 7501028
Filing Date: 2009-03-10
Classification: C21D,H01F

Abstract:
1. Method for producing a non-grain oriented magnetic steel strip or non-grain oriented magnetic steel sheet, comprising the following steps: casting a steel which, in addition to iron, contains unavoidable impurities (in weight %) C: <0.005%, Mn: ≦1.0%, P: <0.8%, Al: <1% and Si providing that 1.4%<% Si+2% Al<2.5% (where % Si=Si content and % Al=Al content) to form a fabricated material, processing the fabricated material to form a hot strip in a hot rolling process at hot rolling temperatures which, starting from ≦1,300° C., are adjusted in such a way that with substantially complete exclusion of a purely austenitic structure (γ phase) a first temperature range is passed through in which a processed steel has an austenite/ferrite dual phase multi-structure (α, γ multi-phases), so the magnetic steel strip or magnetic steel sheet, after a surface treatment including etching, cold rolling and annealing of the hot strip obtained after the hot rolling process, has a magnetic polarisation J wherein a span, A wherein temperature during the hot rolling process is controlled while avoiding the span, A