Semi-hard magnetic alloy for an activation strip, display element, and method for producing a semi-hard magnetic alloy
AssigneeVacuumschmelze GmbH & Co. KG
InventorsOttmar ROTH, Alberto BRACCHI
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Abstract
A semi-hard magnetic alloy for activation strips in magnetic anti-theft systems is provided. The alloy consists essentially of 5 to 15 wt % Ni, 0.5 to 8 wt % Mn, 0.2 to 4 wt % Cu, 0 to 2 wt % Ai, 0 to 2 wt % Ti, the remainder iron and up to 1 wt % impurities, where 0.5 wt %<(Cu+Al+Ti)<5 wt %.
Claims21
A semi-hard magnetic alloy for an activation strip in magnetic anti-theft systems consisting essentially of 5 to 15 wt % Ni, 0.5 to 8 wt % Mn, 0.2 to 4 wt % Cu, 0 to 2 wt % Al, 0 to 2 wt % Ti, the rest iron and up to 1 wt % impurities, where 0.5 wt %<(Cu+Al+Ti)<5 wt %.
A method for producing a semi-hard magnetic alloy for activation strips in magnetic anti-theft systems, the method comprising the following:
- melting an alloy in a vacuum or a protective gas and its subsequent casting into an ingot, the alloy consisting essentially of 5 to 15 wt % Ni, 0.5 to 8 wt % Mn, 0.2 to 4 wt % Cu, 0 to 2 wt % Al, 0 to 2 wt % Ti, the rest iron and up to 1% w/impurities, where 0.5 wt %<(Cu+Al+Ti)<<5 wt %,
- hot-forming the ingot to form a strip at temperatures of between 800° C. and 1300° C.,
- intermediate annealing the strip at a temperature above approx. 800° C.,
- rapid cooling at a speed of at least 500K/min;
- cold-forming to achieve a reduction in cross-section of approx. 90%,
- intermediate annealing at a temperature of approx. 600° C. to 800° C.,
- cold-forming to achieve a reduction in cross-section of at least 85%, and
- tempering at a temperature of 350° C. to 550° C.
Dependencies are inferred from the claim text.