Foundry Technique Research Articles

鋳造技術の現状と将来(<特集>機械工業の現状と将来)

鋳造技術の現状と将来(<特集>機械工業の現状と将来)

III. A Brief Summary of Industrial Radiography and Automatic Processing

Mr. Weston first described the application of radiographic methods in non-destructive testing for the control of foundry technique, showing slides of the apparatus and of radiographs of defective castings.

Shell Mouldings‐a New Foundry Technique

THE process known as Shell Moulding is the most important of a number of changes which have been brought about by the introduction of plastics into foundry technique. These changes result from the use of thermo‐setting resins in foundry sand to bind it, and depend on the temperature properties of the resin, which enable it to be cured at a moderate temperature so as rigidly to bind the mould, while the temperature of the melt is high enough to break down the resin again so that the mould falls away after the casting has been poured.

APPLICATION OF CONTROLLED DIRECTIONAL SOLIDIFICATION TO LARGE STEEL CASTINGS

Large steel castings, particularly those of intricate shape, are nearly always associated with the presence of internal flaws. Necessity for improvement in foundry practice becomes apparent after a study of the present‐day uses of highly stressed castings for structures and for pressure vessels. The methods of improvement fall naturally under three heads. First, the improvement of foundry technique in order to reduce the number of flaws which lie below the standards of acceptability. Second, the development of radiographic inspection as a part of production control in order to discover harmful defects. Third, the extension of repair by welding to all harmful defects in order to insure the integrity of the casting and to prevent its costly rejection.An article, “Steel Casting Design for the Engineer and Foundrymen,” by C. W. Briggs, A. R. Gezelius and A. R. Donaldson was published in the May, 1938, issue of the Journal. The article derived from an intensive study by the Naval Research Laboratory of the phenomena of directional solidification. Following the laboratory study, tests were made at the steel foundry in the Norfolk Navy Yard in order to determine the application of the laboratory findings to actual foundry production. Cooperative effort between the laboratory and the navy yard was most successful. Thus, it becomes a great privilege to publish results of the foundry experience in the ensuing article as a sequel to the earlier article on laboratory development.