FOUNDRY METHODS, CASTING RESULTS, AND MECHANICAL PROPERTIES OBTAINED IN SCALING UP UNIDIRECTIONALLY SOLIDIFIED PLATES.
Abstract
The program was initiated to investigate the feasibility of controlling the solidification of 48 x 60 inch plate castings, 4 and 5 inches thick, to produce a wholly columnar grain structure. One of the major faces of the mold cavity was formed by a graphite slab and the other by 3 sheets of a proprietary insulating material. Plates were cast from the same alloy steel composition currently used for forged 175mm gun tubes. Four 4-inch thick and four 5-inch thick plates were cast. A 4-inch thick plate was cast vertically in a sand mole for use as a control. Sound plates were heat treated to 257-277 BHN or 357-377 BHN. Charpy 'V' notch impact bars were machined from 1-1/4 in. diameter cylinders, core drilled from four locations near the corners of the plates. The notch of the bars were located close to the chill side or the insulated side of the plate. Impact tests were conducted at -40F. The aforementioned system of heat extraction and insulation did not produce a wholly columnar grain structure. All of the plates contained a columnar zone which extended 1-1/2 to 2-3/4 inches from the chilled side of the plate. The balance of the cross section of the plate contained a fine equiaxed grain structure. Notch toughness normal to the direction of heat extraction during solidification decreased significantly in the equiaxed portions of the plates. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Jun 01, 1969
- Accession Number
- AD0701161
Entities
People
- D. K. Hannibal