Patent ID: 6739383
Filing Date: 2004-05-25
Classification: B22D,C22C

Abstract:
A process for the continuous casting of an austenitic stainless steel strip having a thickness of less than or equal to 10 mm, directly from liquid metal, between two cooled horizontal rolls, comprising the following steps:choosing the composition of said steel, in percentages by weight, to be: C %&lE;0.08; Si %&lE;1; P %&lE;0.04; Mn %&lE;2; Cr % between 17 and 20; Ni % between 8 and 10.5; S % between 0.007 and 0.040; the balance being iron and impurities resulting from the smelting; choosing the Creq/Nieq ratio to be between 1.70 and 1.90 with: Creq(%)=Cr%+1.37Mo%+1.5Si%+2Nb%+3Ti% andNieq(%)=Ni%+0.31Mn%+22C%+14.2N%+Cu%; providing the surface of the rolls with touching dimples of approximately circular or elliptical cross section, having a diameter of 100 to 1500 &mgr;m and a depth of 20 to 150 &mgr;m; and surrounding the meniscus with an inert gas which is a gas soluble in the steel or a mixture of such gases, or is at least 50% by volume of such a gas or gas mixture, to produce a strip surface which is free of microcracks.