研究論文
桑名地方における薄肉ねずみ鋳鉄品の製造に関する研究
1965 年 37 巻 8 号 p. 686-694
詳細
1965 年 37 巻 8 号 p. 686-694
In view of the fact that casting method of thin grey iron is one ot the important subjects at present, the investigation was done on “Charcoal box-irons for export” and “rings for setting cauldrons on ovens” out of many thin section grey iron castings produced in Kuwana District, where they have had so much experiences in this field of casting for more than 50 years.
By studying the foundry methods of them the datas and the production methods on the thin section grey iron casting were obtained. Reasons for selecting these two products are as follows: Both of Them are moulded with natural green sand, but each has the following antithetic features, i.e., a charcoal box-iron is of case-type, (about 3mm thickness, its three dimentions about 200mm×100mm×80mm) is gilded after polish. While a cauldron-ring is of very slender flat ring type (thickness: breadth: circular length=1 : 13 : 290∼1 : 20 : 1,100), and the producers have been making the utmost efforts to make them as thin and light as possible.
The results were as follows :
1) Permeability of sand mold should be kept particularly as high as possible in such thin castings.
2) Moisture in raw sand was found to be 10∼13%.
The percentage seemed to be too high at first, but from the results of laboratory experiments this amount was proved to be effective for good permeability, high strength of mold and better efficiency of molding processes.
3) As natural green sand is insensible to moisture variations and low in price, it is a reasonable management to renew the sand which strives to diminish defects of casting and to cut down the production cost.
4) Charges for cupola are restricted to pig irons and return scrap of these own products.
Pouring temperature is kept at more than 1,450°C and 1,480°C for box-irons and cauldron-rings respectively.
The charge compositions and the high pouring temperature improve the flow of molten iron.
5) Gating and pouring systems can tolerably be addapted to several well-known experimental formulas on casting design.
