PURPOSE: To finely disperse a B compound and to improve a hot workability by cooling while stirring a molten steel and casting with the degree of superheat specified.
CONSTITUTION: The molten metal of a boron-contained austenitic stainless steel is cooled while stirred mechanically or electromagnetically, and the casting is performed under the condition of the superheat at 5°C or less. Also, the casting is performed under the condition in which the metal is cooled by stirring to the temp. at the liquidus line or below and making a semi-solidified slurry state with the solidus rate at 0.50 or less. By this casting, in the steel ingot by an ingot-making as well as a cast billet by a continuous casting, the austenite grain is micronized and also the B compound is finely dispersed and precipitated. The contents of B in steel is desirably 0.7-4.0mass%.
NANBA AKIHIKO
NODA MASATO
