Fabrication of very high strength dual phase steel strip by hot and cold rolling and aluminising for the production of anti-implosion belts for television sets

摘要

The fabrication of a dual phase steel strip comprises: (a) producing steel with a given composition; (b) reheating a slab or ingot of this steel to a temperature of 1,100 and 1,300 degreesC; (c) hot rolling the slab or ingot with a finishing temperature greater than the Ar3 temperature of the steel; (d) cooling the strip at a speed of 1-500 degreesC/second; (e) coiling the strip at a temperature of 300-720 degreesC; (f) cold rolling the strip; (g) subjecting the cold rolled strip to a continuous annealing operation at a temperature greater than the Ac1 temperature; (h) cooling the annealed strip at a speed greater than 2 degreesC/second to an aluminising temperature; (i) aluminising the strip by soaking in an aluminium based bath at a temperature of 650-720 degreesC and; (j) cooling the strip to ambient temperature at a speed greater than 2 degreesC/second. Independent claims are also included for: (a) steel strip fabricated in this manner with a structure made up of a ferrite matrix containing 5-30% of martensite and at least 2% of carbide phases; and (b) an anti-implosion belt for a television set made from this steel strip.