Accession Number : AD0620558

Title :   INSULATION OF RISERS FOR FERROUS CASTINGS,

Corporate Author : NAVAL RESEARCH LAB WASHINGTON D C

Personal Author(s) : Power,J. R.

Report Date : 24 SEP 1948

Pagination or Media Count : 15

Abstract : The report describes experiments conducted with an inexpensive method of insulating risers on iron and steel castings in order to obtain a higher yield. The insulating material, a mixture of 40 percent by weight of sawdust with 26 percent dextrine and 34 percent water, is pressed into the desired shapes, dried, coated with a refractory wash, and molded in position upon a pattern to form a riser cavity. A series of steel and cast-iron cubes of various sizes were cast with insulated and uninsulated risers to compare feeding efficiencies. When insulated risers are employed, the risers can be reduced in volume by at least 50 percent. This riser insulating method has these disadvantages: (1) it produces a segregated area of high carbon content in the casting, (2) it causes boiling or spattering of the metal in the riser unless precautions are taken to keep the insulation dry and (3) the amount of gases discharged to the foundry atmosphere is excessive. (Author)

Descriptors :   (*MOLDINGS, THERMAL INSULATION), (*CASTING, IRON ALLOYS), (*IRON, CASTINGS), (*STEEL, CASTINGS), MOLDING MATERIALS

Distribution Statement : APPROVED FOR PUBLIC RELEASE