Abstract
This report is related the foundry practice for the castings of cupper-alloy ; each weights is 295kg, 200kg, 187kg and 120kg, thickness is 10～20m/m, demanding 7kg/cm2 pressure tight.
The successful production of castings chiefly depends upon their moulding sand, moulding technique, melting process, alloying and casting temperature.
Then discussed most suitable condition from the experiment deta and obtained the good results by used the follow method ;－
1) Pattern ; The pattern mad stricfle food of plain type so as to keep the cost of pattern making low.
2) Moulding ; Hand moulding and drying in ofen and graphite coating,
3) Machining allowance ; As a general rule, the as-cast surface is excellent for hydraulically soundness so that attached as possible as small machning allowance (2～2.5m/m)
4) Alloying and melting ;
Charge ;－Careful attention paid in the selection of scrap and employed the re-melting method
Composition ;－Cu 88%, Sn 10% Zn 2%
Furnace ;－ High frequency induction furnace capacity 150kw.
5) Flux ;－ p-Cu 0.02% charcoal 0.5%, fluorspar 0.01% in Weight percentage for 300kg charge.
6) Melting temperature ;－ 1350°C
7) Casting temperature ;－ 1250°C
