METHOD FOR CONTINUOUSLY CASTING AUSTENITIC STAINLESS STEEL STRIP ON SHIFTING WALL SURFACE OR BETWEEN WALL SURFACE HAVING RECESSED PARTS ON SURFACE AND CASTING APPARATUS

摘要

PROBLEM TO BE SOLVED: To reduce micro-cracking and longitudinal cracking by regulating the composition of liquid metal and the shape of recessed parts on a shifting wall surface, etc. SOLUTION: The composition of the liquid metal is by wt.% of =0.08 C, =1 Si, =2 Mn, =0.045 P, =0.03 S, 17.0-20.0 Cr and 8.0-10.5 Ni and =1.55 ratio of Crequ /Niequ . Wherein, the Crequ and the Niequ as shown in the equation I and the equation II, respectively. Cr=equ %Cr+1.37%Mb+1.5%Si+2%Nb+3%Ti...(I) Niequ =%Ni+0.31% Mn+22%C+14.2%N+%Cu...(II) Then, on the whole shifting wall surface, the mutually approached recessed parts having 100-1500m diameter and 20-150m depth are provided. Further, inert gas composed of at least partially soluble gas in the steel is used. By this method, the vol. variation caused by ferrite austenite transformation started before completing the solidification is remarkably made to small and the micro-crack is reduced. Further, since the recessed parts serve as shrinkage joint to the metal during solidifying, the distributing condition of strain is improved and the cracking is reduced.