Abstract: A method and an apparatus for manufacturing a crystalline blast furnace slag, which comprises: endlessly connecting at prescribed intervals a plurality of rectangular metal cooling bodies each with a hollow for cooling water, to form a plurality of cooling grooves with a width at the top end thereof of from 40 to 80 mm corresponding to said prescribed intervals and a depth of from 100 to 300 mm and becoming narrower toward the depth thereof, each between two adjacent ones of said cooling bodies; continuously pouring a molten blast furnace slag sequentially into said plurality of cooling grooves in an atmosphere of an inert gas and/or a reducing gas, while moving said plurality of cooling bodies endlessly connected in circulation in the connecting direction thereof; and, circulating a cooling water through said hollows for cooling water of said plurality of cooling bodies during the pouring of said molten blast furnace slag into said plurality of cooling grooves, to cool said plurality of cooling bodies, there

Abstract: An apparatus for vitrifying blast furnace slag, which comprises:an endless conveyor belt formed by endlessly connecting a plurality of rectangular cooling metal members, each of said cooling metal members having a plurality of narrow and deep cooling grooves on the outer surface thereof for rapidly cooling and solidifying a molten blast furnace slag into a vitreous blast furnace slag; a driving means for travelling said endless conveyor belt; a molten slag container, arranged above the upstream of the upper forwarding position of said endless conveyor belt, for pouring a molten blast furnace slag into said cooling grooves; a stripper arranged, in the upstream of the lower returning position of said endless conveyor belt, at a prescribed position adjacent to the back surface of said endless conveyor belt, for taking out a cooled and solidified vitreous blast furnace slag in said cooling grooves; and, a cooling means arranged at a prescribed position in the lower returning position of said endless conveyor belt

Abstract: An apparatus for manufacturing a vitreous blast furnace slag, comprises a rotary drum having a circular barrel formed by endlessly connecting a plurality of rectangular cooling metal members, each of said cooling metal members having a plurality of narrow and deep cooling grooves on the outer surface thereof for rapidly cooling and solidifying a molten blast furnace slag into a vitreous blast furnace slag; a driving mechanism for rotating said rotary drum; a molten blast furnace slag feeder arranged above said rotary drum for pouring a molten blast furnace slag into said cooling grooves; a stripper stationarily arranged at a prescribed position adjacent to the inner surface of the barrel of said rotary drum, for taking out a cooled and solidified vitreous blast furnace slag in said cooling grooves; and, a cooling tank containing cooling water, arranged below said rotary drum so that the lower portion of the barrel of said rotary drum is immersed in the cooling water for cooling said cooling metal members heat

Abstract: This invention relates to a high strength non-magnetic stainless steel for a spring, which comprises at most 0.2% of carbon, at most 3% of manganese, at most 0.045% of phosphorus, at most 0.03% of sulfur, at most 1% of silicon, 18 to 20% of chromium, 8 to 12% of nickel, 0.08 to 0.25% of nitrogen and the balance of iron and which is subjected to a heat treatment and a cold or warm working.