Cast Iron Mould Research Articles

The feedstock: copper and copper alloys

The production of feedstock in the copper and copper alloy rolled-metals industry covers a very wide range of activities and no attempt is made to examine these in depth. A general review is given on the two principal methods used for producing slabs or cake for hot rolling, and of the four principal methods for producing generally smaller cross-section slabs or section for cold rolling. These include static casting into copper-faced, water-cooled moulds and cast iron moulds; vertical semi-continuous casting into direct chill moulds; and horizontal submerged die casting using graphite moulds. Some of the recurring problems associated with each method are discussed and typical yield figures quoted. The main objective is to review the developments and changes in practice that have taken place over the past 10 years, to comment on the reasons for these changes, and, finally, to examine the likely trends of the industry in the next 10 years

Precipitation of iron-rich particles in extruded leaded brass rods on reheating

AbstractThe formation of iron-rich particles in extruded brass rods has been observed on reheating for hot stamping and the rate of precipitation was determined in samples of BS2874:CZ121 type brass rods reheated to temperatures within the range 630°–825°C. The rate-controlling factors were found to be casting method, extrusion preheat time, silicon content, and reheat temperature; the lowest and highest precipitation rates upon reheating were observed respectively in a low-(<0·0001%) silicon rod extruded after a short preheat from a semi-continuous cast billet and a rod containing 0·0006%Si extruded after a long preheat from a static chill-cast billet (poured in a cast iron mould).

大型鋼塊用ダクタイル鋳鉄鋳型の寿命について

The experimental and practical results of the small ingot mould made of ductile cast iron were reported by many authors. However in the case of the large ingot mould, it seems to be not yet reported in detail.Therefore, the authors made the experiment on the large ingot mould, i.e., C-61 type (weight: 5, 230kg, wall thickness 130mm) and C-56 type (weight: 4, 900kg, wall thickness 125 mm) which are used at Yawata Iron & Steel Works, for the purpose of comparing ductile cast iron with ordinary cast iron.As the result, it was found that the ductile cast iron mould has a longer life. On the other hand, however, some peculiar defects appeared on the inner surface of them in the course of ingot making. Authors diseussed those results mainly on the points of its life, surface crazing and cracking, and change of the microstructure.List of derived conclusions are as follows:1. The favorable result can be expected from the large ductile cast iron mould.2. It has superior resistance to crazing and few exfoliation is noticed on the inner surface of tested moulds.3. Pearlite and spheroidized graphites are decomposed into massive graphites by repeated heatings to 700-750°C.4. Peculiar cracks of ductile cast iron mould must be prevented by the improvement of casting technique or the development of the ingot mould design.

鑄鋼製鑄型に就て(I)

The ingot mould made of cast steel, instead of cast iron, were adopted by our Works to lessen the increased consumption caused by lack of pig iron and coke of good quality.The results were satisfactory enough: the slab mould weighing 1, 200kg endured to the contineous use of average 142 times. The suitable carbon content was 0.4-0.5%. The special device was taken to avoid its strain by heat.The author expects, under present condition of Japan, 3-5 times durability compared to that of cast iron mould, whereas the manufacturing cost of it falls 2-3 times of the latter.

Kristalvorming bij tin

Summary Experiments were carried out with the object of investigating the way in which tin crystals are formed from the pure melt. For this purpose a quantity of liquid tin was slowly cooled in a cast-iron mould, the crystallisation being interrupted some time after the beginning of the solidification by letting the still fluid portion run off. The partially developed crystals permitted to study the formation of crystals and the influence of the rate of cooling.

Societies and Academies

LONDON Institute of Metals (Annual General Meeting), March 7. G. A. HANKXNTS and C. W. ALDOUS: Minimum dimensions of test samples for Brinell and diamond pyramid hardness tests. The metals investigated include copper, brass, aluminium and steel. A width of test-specimen of 4 £ times the diameter of the impression is satisfactory for accurate Brinell tests. For Brinell tests, the limiting value of the ratio of thickness of test sample to depth of impression for accurate results appears to be a characteristic of the test material; a value of the ratio of 6 is required for mild steel, about 15 for copper and more than 20 for spring steej. For diamond pyramid hardness tests a limiting value of the ratio of test-sample thickness to impression diagonal of 1J gives results which are practically independent of test-sample thickness except with soft copper and soft brass. I. G. SLATER: Note on the influence of gases in an 8 per cent copper-aluminium alloy on normal and inverse segregation. In a sand-cast ingot, 3 in. in diameter by 3 in., segregation is inverse with very gassy melts but normal with degassed melts. GILBERT RIGG: The diffusion of zinc and iron at temperatures below the melting point of zinc. When clean rolled zinc sheet is heated in close contact with clean iron, diffusion commences at below 300 ° C. and is fairly rapid at above 380 ° C.; it proceeds by the formation of cones of diffusion products, which spread out from isolated points where the contact between the metals is most perfect, and gradually penetrate into the zinc and across its surface. Two well-defined layers of diffusion products are formed, a thin layer of constant thickness (about 0-08 mm.) containing about 17 per cent iron being next to the iron, and a thicker layer containing 0-11 per cent iron outside this. On continued heating, the thin layer moves towards the zinc, being continuously converted into the zinc-rich layer; this would seem to indicate that the principal diffusion constituent is the iron. H. G. GOUGH, H. L. Cox and D. G. SOPWITH: A study of the influence of the intercrystalline boundary on fatigue characteristics. With the object of studying the process of fatigue in relation to crystalline boundaries, tests under alternating torsional stresses have been made on three specimens of aluminium each consisting of two crystals. The distribution of slip bands showed that the effect of the boundaries on the distribution of stress was extremely slight, each crystal of each specimen behaving as if it alone composed the whole specimen. It appears that the presence of intercrystalline boundaries may considerably strengthen the constituent crystals against fatigue; but that the effect of the boundaries on the distribution or even on the amount of slip is very small. It is probable that the major effect of the boundary may lie in some restriction of strain that it imposes. C. E. PEARSON: The viscous properties of extruded eutectic alloys of lead-tin and bismuth-tin. Elongations up to 2,000 per cent have been obtained in tensile tests employing prolonged loading. An apparatus designed to maintain a constant stress on the test-piece during extension shows that deformation takes place at a uniform rate which is greatest in freshly extruded rods and decreases with age pr on annealing. The viscosity is not that of simple liquids, but resembles that shown by some disperse systems in which the viscosity coefficient is a function of the stress causing flow. The locus of viscous flow is found to be at the inter-crystalline boundaries. E. W. FELL: A note on some formulae concerning viscous and plastic flow in soft metals. In particular, the flow of the metal in a prolonged ball-hardness test is compared with the flow in tensile test-pieces under a constant stress per unit area of cross-section. A. PORTE VIN and P. BASTIEN: Castability of ternary alloys. The ability of a molten metal or alloy to fill a mould completely is termed ‘castability’; it can be determined by ascertaining the length of a spiral cast-iron mould filled by the metal under predetermined casting conditions. The castability of a pure metal is a linear function of the difference between the pouring temperature 6 and the melting point F; the slopes of the castability (Q?F) curves vary with the viscosity of the metal. The castability of binary alloys varies with the solidification range and with the mode of crystallisation, being greater when polyhedral crystals separate than when the primary crystals are dendritic. Maximum castability occurs with the eutectic composition and minimum at the limit of solid solubility. The castability of ternary alloys generally varies inversely with the primary solidification range.

Societies and Academies

Societies and Academies