Process and apparatus for continuously casting a strand of inoxidable austenitic steel on a moving wall or in between two moving walls whose surfaces are grooved

摘要

Austenitic stainless steel is continuously cast to form a thin band on one or between two moving walls with dimpled surfaces and under a blanket of inert gas of controlled composition which is at least partly soluble in the steel, the dimples being interconnected and having diameters 100-1500, preferably 700-1500 mu m and depth 20-150, preferably 80-120 mu m. The steel comprises (wt.%): 17.0-20.0 chromium, 8.0-10.5 nickel and up to 0.08 carbon, 1 silicon, 2 manganese, 0.045 phosphorous and 0.030 sulphur.The ratio A/B is over 1.55, preferably 1.55-1.70, where A=%Cr+1.37 %molybdenum+1.5 %Si+2 %niobium+3 %titanium and B=%Ni+0.31 %Mn+22 %C+14.2 %nitrogen+%copper. Also claimed is a casting device comprising one or two cooled moving walls having said dimples and with a system for controlling the atmosphere therein.