MANUFACTURE OF DUCTILE CAST IRON PIPE WITH HIGH STRENGTH

摘要

PURPOSE:To manufacture simply a ductile cast iron pipe with high strength by pouring necessary boiling water on the inside of a centrifugally cast ductile cast iron pipe. CONSTITUTION:Molten ductile cast iron contg. 2.2-3.5wt% Si is centrifugally cast. When the temp. of the resulting cast pipe is in the austenite range, the cast pipe is rapidly cooled to 500-550 deg.C without forming pearlite by pouring necessary boiling water on the inside of the pipe while rotating the pipe. The pipe is then air-cooled so as to form a bentonite structure. During the air-cooling, the pipe is rotated or kept stationary.