Pouring temperature

The zinc is normally melted in a gas, oU, or coal-fired reverberatory furnace with a capacity up to 100 tons or in a low frequency induction furnace with a capacity of a few tons. The more highly aUoyed compositions are more effectively melted and mixed in low frequency induction furnaces. The furnace must be refractory-lined to eliminate iron pickup by the molten metal. The metal temperature is maintained below 500°C to minimize loss by oxidation. A ladle is used to transfer the metal for casting into molds the pouring temperature is usuaUy ca 440°C. Zinc scrap is not generaUy suitable for remelting because it may contain undesirable impurities. 

The pour temperature will depend on equipment and rate and degree of cooling available on the filling line. With slow cooling rate, the cooling cycle must be done without covers to prevent condensation inside containers. 

Add Part A to Part B with good mixing. (4.) When homogeneous, cool to 60C and add Part C with continued mixing. (5.) Cool to suitable pour temperature, e.g., >50C. 

The pour temperature will depend on equipment, rate and... 

La relation (24) permet aussi de reformuler liquation WLF (Ferry, 1961). En admettant que pour le liquide / est une fonction lineaire de la temperature, et en adoptant pour temperature de reference Tg,... 

Shrinkage porosity Gas porosity Appears as a localized honeycomb or mottled pattern due to improper pouring temperature or alloy composition (e.g., A1 alloys) Round or elongated smooth, dark spots located individually or in clusters distributed randomly in the casting due to release of gas during solidification or evaporation of moisture from volatiles from the mold surface... 

Picric acid was used as a grenade and mine filling. It needs a high pouring temperature, which is undesirable. However, the solidification point can be depressed by the addition of nitronaphthalene, dinitrobenzene or trinitrocresol. 

By using the available heat calculated for the flue temperature and the heat contained in the metal at the pouring temperature (475 Btu/lb or 1100 kJ/kg), the heat lost to the environment from the furnace is calculated. Assuming the heat loss is constant, the amount of fuel required at various oxygen participation levels is... 

They have a low pour temperature, so cold engine starts result in less wear. 

A survey of the consumption and emission levels of the various technical modifications of cupola melting was set up by Neumann in 1994, as given below. All data refer to a system for the production of 10 tonne/h nodular iron with 3.6% C and 1.6% Si and at a pouring temperature of 1530 °C. The balances in Figure 10.1 show inputs, outputs and process temperatures. The latter will be higher compared to operational practice. Comparison of the various balances allows an assessment of the effect of all the modifications. 

Refer to appendix for typical pouring temperatures. Includes gray and ductile iron. 

Generally aU ferrous and non-ferrous metals can be cast using thus method but is unsuitable for low and medium carbon steels due to the possibility of carbon pick up. Because the foam pattern has to decompose to produce the casting, metal pouring temperatures above 540 °C are usually required so that casting of low temperature metals is limited. 

At the pouring temperature, the suppository mass should be sufficiently viscous to prevent the settling of dispersed particles during the filUng process. 

First, a proper pouring temperature has to be chosen to assure that the mass will not solidify during the filling... 

Choice of pouring temperature also has to do with the behaviour of the suppository base upon cooling. For hard fat the temperature - time relation is shown in Fig. 11.8. 

The choice of the pouring temperature also depends on the pouring (filling) method ... 

Filling a composite metal mold with cadre the pouring temperature is chosen just high enough to prevent solidification before aU cavities are filled 34—35 °C will usually do. 

For filling from a suppository filling machine the pouring temperature is chosen just above the start of the solidification range. 

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