Foseco Non-Ferrous Foundryman’s Handbook Part 15 potx

268 Foseco Non-Ferrous Foundryman’s Handbook than the pouring temperature). Read expansion or shrinkage (S) expressed as a percentage on the horizontal axis. (c) Mould wall movement (M%) depends on the hardness of the mould and can vary from zero for hard silicate or resin moulds to 2% for green sand moulds with a mould hardness of 85° (B scale). Add the mould wall movement from the expansion to give a final value of S. If this is positive or zero the casting will not need feeding. (d) The weight of metal in the feeder under consideration (W F ). The total weight of casting (W C ) which can be fed from a feeder of weight W F is W C = C/100 ϫ 100/S ϫ W F (11) If the total weight of casting section (W t ) which requires feeding is greater than W C then increase the dimensions of the feeder until: W T = W C i.e. W F = W T ϫ 100/C ϫ S/100 (12) 4. Calculate the dimensions of the feeder neck (a) Top feeders No calculation of feeder-neck dimensions are required. If possible feeder sleeves should be used with breaker cores. (b) Side feeders The required feeder-neck dimensions are obtained from the calculation of the neck modulus (M N ) by applying the ratios: M C :M N :M F = 1.0:1.1 ͱST/100:1.2ͱST/100 then using either the endless bar equation (Fig. 17.5 g) or the diagram in Fig. 17.6. Foseco feeding systems Introduction Foseco provides complete feeding systems for foundries, comprising: Sleeves – insulating and exothermic for all metals Breaker cores – to aid removal of the feeder from the casting Application technology – to suit the particular moulds and moulding machine used Aids to the calculation of feeder requirements Feeding systems 269 Range of feeder products The Foseco range of products comprises: Product name Type Application casting alloy Remarks KALMIN S Insulating Al, Cu base iron, steel extend solidification time by 2.0–2.2 KALMINEX 2000 Insulating and exothermic iron, steel extend solidification time by 2.5–2.7 FEEDEX HD Highly exothermic iron, steel small riser-to-casting contact area use where application area is limited KALMINEX Insulating and exothermic iron, steel for large diameter feeders KALBORD Insulating iron, steel copper base in form of jointed mats for large feeders KALPAD Insulating iron, steel copper base prefabricated boards or shapes KAPEX Insulating Al, Cu base iron, steel prefabricated feeder lids, replace hot-topping compounds KALMIN S, KALMINEX 2000, FEEDEX HD and KALMINEX products are supplied as prefabricated sleeves in a wide range of sizes and shapes, with or without breaker cores. KALMIN S feeder sleeves By using a high proportion of light refractory raw materials, a density of 0.45 g/cm 3 is achieved, ensuring highly insulating properties. KALMIN S Figure 17.8 Foseco sleeve types. 270 Foseco Non-Ferrous Foundryman’s Handbook Figure 17.9 Example of sleeve support on a moulding machine pattern plate. Figure 17.10 An insertable KALMINEX sleeve with breaker core attached and a typical sleeve pattern. Figure 17.11 The KALSERT system in operation. KALMINEX sleeves being inserted into green sand moulds on an automatic moulding line. Feeding systems 271 sleeves are particularly suitable for aluminium, copper-base and iron alloy sand castings since the raw materials used are neutral to both the casting alloys and to the moulding sand. KALMIN S sleeves are supplied as “parallel conical”, “opposite conical”, or cylindrical sleeves for either ram- up application or insertion into cope or drag, Figs 17.8, 17.9, 17.10 and 17.11. They can be applied in the following moulding systems: Moulding method KALMIN S feeder sleeve type Insert sleeves into the turned-over cope mould especially in automatic moulding lines Parallel conical insert sleeves in conjunction with Foseco Sleeve Patterns Insertion of the feeder sleeve from the top of the cope mould into the cavity created by means of a suitable sleeve pattern which is drawn after moulding Opposite conical sleeve Ram-up on the pattern plate in a machine moulding or a hand-moulding operation Parallel conical insert feeder sleeve, opposite conical feeder sleeve or cylindrical sleeve Insert sleeve in a vertically parted moulding system Parallel conical insert and/or opposite conical feeder sleeve Insert sleeves into shell moulds Parallel conical insert and/or opposite conical feeder sleeve Application of feeder sleeves in a drag mould over a feeder base or bridge core Parallel conical feeder sleeve as floating sleeve system KALMIN S feeder sleeves extend the solidification times by a factor of 2.0–2.2 compared to natural sand feeders of the same size. From these results, Modulus Extension Factors (MEFs) of 1.4–1.5 have been calcu- lated. Though KALMIN S feeder sleeves can give more than 33% of their feeder volume to the solidifying casting, it is recommended that a maximum of one-third of the feed metal volume should be fed into the casting so that the residual feeder modulus is adequate in relation to the casting modulus at the end of solidification. For this reason, it is recommended to consider modulus as well as solidification shrinkage in order to determine the correct feeder. Foseco provides tables allowing KALMIN S feeders to be selected with the desired modulus, volume (capacity) and dimensions. 272 Foseco Non-Ferrous Foundryman’s Handbook KALMINEX 2000 feeder sleeves KALMINEX 2000 is a highly insulating and exothermic feeder sleeve material in the form of prefabricated sleeves for iron and steel casting in the modulus range between 1.0 and 3.2 cm. For light and other non-ferrous alloys the KALMINEX 2000 feeder sleeve material is not recommended. The manufacturing process specifically developed for this unique feeder sleeve material not only ensures a low density of 0.59 g/cm and, therefore, a high grade of insulation but also an additional exothermic reaction peaking at 1600°C. Due to the strength of the KALMINEX 2000 feeder sleeves, they can often be rammed up directly on the pattern plate on many moulding machines. KALMINEX 2000 feeder sleeves can be applied in the following moulding systems: Application method KALMINEX 2000 feeder shape Insert sleeves into the turned-over cope mould especially in automatic moulding lines Parallel conical insert sleeves in conjunction with FOSECO Sleeve Patterns Ram-up on the pattern plate in a machine moulding or a hand-moulding system Parallel conical insert feeder sleeve, opposite conical feeder sleeve or cylindrical sleeve Insert sleeve in a vertically parted moulding system Parallel conical insert and/or opposite conical feeder sleeve Insert sleeve into shell moulds Parallel conical insert and/or opposite conical feeder sleeve Application of feeder sleeves in a drag mould over a feeder base or on a bridge core Parallel conical feeder sleeve as floating sleeve system When determining the solidification times with KALMINEX 2000 feeder sleeves it has been found that they extend the solidification time by a factor of 2.5–2.7 compared to a natural sand feeder of the same size. From these results Modulus Extension Factors (MEFs) have been calculated between 1.58 and 1.64. Foseco provides tables allowing KALMINEX 2000 feeders to be selected with the desired modulus, volume (capacity) and dimensions. Under specific practical conditions it has been found that the KALMINEX 2000 feeder sleeves can render 64% of their volume to the solidifying casting. When using feeders with the correct modulus it is necessary to take into account that the modulus of the residual feeder – if more than 33% of the feeder volume is fed into the casting – may not be adequate in relation to the Feeding systems 273 casting modulus towards the end of the solidification. Therefore, it is essential to calculate shrinkage as well as modulus in order to determine the correct feeder sleeve. FEEDEX HD V-sleeves FEEDEX HD V feeder sleeves are used for iron and steel casting alloys. FEEDEX HD is a fast-igniting, highly exothermic and pressure-resistant feeder sleeve material. The sleeves possess a small feeder volume, a massive wall, but only a small riser-to-casting contact area, Fig. 17.12. They are, therefore, specially suited for use for “spot feeding” on casting sections which have a limited feeder sleeve application area. The sleeves are located onto the pattern plate using special locating pins, the majority are supplied with shell-moulded breaker cores. Owing to their small aperture, these breaker cores are not recommended for steel casting. FEEDEX HD V-sleeves are particularly useful for ductile iron castings since with their low volume shrinkage of below 3%, a modulus-controlled KALMIN or KALMINEX 2000 feeder will often have more liquid metal than is necessary. The very high modulus and relatively low volume of FEEDEX HDV gives improved yield. In many ductile iron applications, the small breaker core aperture of the feeder means that the feeder is separated from the casting during the shakeout operation and the cleaning cost is reduced. Figure 17.12 FEEDEX HD V-sleeve. 274 Foseco Non-Ferrous Foundryman’s Handbook Figure 17.13 The application of FEEDEX HD V-sleeves to ductile iron castings. Feeding systems 275 When used in ductile iron applications, it is important to note that the high temperature reached in the highly exothermic feeder can cause residual magnesium in the iron to be oxidised so that there may be a danger of denodularisation on the casting–feeder interface. To avoid this, residual Mg should be greater than 0.045%, inoculation practice should be optimised and thick breaker cores used. Note that when calculating FEEDEX metal volume, only 50% of the capacity should be assumed since part of the metal in the feeder will be lamellar due to oxidation of the Mg in the feeder cavity. Figure 17.13 shows examples of the use of FEEDEX HD V-sleeves on ductile iron castings. KALMINEX feeder sleeves KALMINEX exothermic-insulating feeder sleeves are used for all iron and steel casting alloys. They are supplied with feeder diameters from 80 to 850 mm for the modulus range between 2.4 and 22.0 cm and are suitable for larger-sized castings. The manufacturing process specifically developed for this exothermic- insulating product and the selection of specific raw materials give a total closed pore volume of nearly 50%. The excellent heat insulation resulting from the low density (compared with moulding sand) is enhanced by an exothermic reaction. When determining the solidification times with KALMINEX feeder sleeves it has been found that they extend the solidification time by a factor of 2.0–2.4 compared to the natural sand feeders of the same size. From these results Modulus Extension Factors (MEFs) of 1.4–1.55 have been found. Under practical conditions it has been found that KALMINEX feeders when adequately covered with KAPEX lids or a suitable APC (anti-piping compound) may render up to 64% of their contents into the casting. When using feeders with the correct modulus it is necessary to take into account that the modulus of the residual feeder – if more than 33% of the feeder volume is fed into the casting – may not be adequate in relation to the casting modulus towards the end of the solidification. Therefore it is essential to calculate shrinkage as well as modulus when determining the size of the feeder sleeves. Foseco provides tables allowing KALMINEX feeders to be selected with the desired modulus, volume (capacity) and dimensions. Several different shapes of KALMINEX feeders are available, Fig. 17.14a,b,c. Breaker cores are generally made of chromite sand, although they can be produced in silica sand. KALBORD insulating material Although in theory there is no upper limit of inside diameter for using prefabricated feeder lining shapes for inside diameters above about 500 mm, 276 Foseco Non-Ferrous Foundryman’s Handbook Figure 17.14 (a) KALMINEX cylindrical feeder sleeve with breaker core and KAPEX lid. (b) KALMINEX TA sleeve. Thickness Width Feeding systems 277 manufacture, transport and storage become increasingly inconvenient. For this reason Foseco has developed KALBORD flexible insulating material in the form of jointed mats. They can be easily wrapped around a feeder pattern or made up into conventional sleeves as required for the production of insulating feeders for very large steel, iron and copper-based alloy castings, Fig. 17.15. KALBORD mats are available with 30 mm and 60 mm thicknesses in widths up to 400 mm and lengths 1020 or 1570 mm. Their excellent flexibility permits the lining of irregular feeder shapes. The mat is most easily separated or shortened with a saw blade. Produced from high heat insulating materials, 30 mm mats achieve a 1.3 fold and 60 mm mats a 1.4 fold extension of the modulus. It is recommended that KALBORD feeders are covered with FERRUX anti-piping powder. Figure 17.14 (c) KALMINEX oval sleeve. Figure 17.15 KALBORD jointed mats. [...]... stock of THERMEXO 286 Foseco Non-Ferrous Foundryman’s Handbook FEEDOL anti-piping compounds for all non-ferrous alloys The lower casting temperatures and the differing chemical requirements for non-ferrous alloys necessitate a completely different range of anti-piping compounds than that used on ferrous castings FEEDOL is the name given to Foseco s range of anti-piping compounds for non-ferrous castings... since feeder sleeves are simply placed on the drag parting line The method is applicable for all moulding machines having a horizontal mould parting line No problems are encountered regarding Ø D0 Cope pattern H M Ø DU A Drag pattern 2° B M L 2° DU1 DU2 Bottom view Figure 17.18 Sleeve pattern for a floating sleeve 282 Foseco Non-Ferrous Foundryman’s Handbook strength, springback etc of the feeder sleeve... and the breaker core from the superheat upon or before reaching liquidus Some of the standard forms of breaker core available from Foseco are shown in Fig 17.17 Foseco feeder sleeves can be ordered with or without breaker cores attached 280 Foseco Non-Ferrous Foundryman’s Handbook 10° Ø D1 Ø d2 Ø d1 Ø D1 Ø d2 Ø d1 t 0.5t ØN Ø D2 ØN Ø D2 1 to 1.5 for all types T Ø N1 Ø N2 Ø D2 Figure 17.17 20° t 0.13N...278 Foseco Non-Ferrous Foundryman’s Handbook KALPAD prefabricated boards and shapes KALPAD has been developed by Foseco to provide a lightweight, highly refractory insulating material to avoid metal padding and to promote directional solidification If KALPAD... ͑weight͒ 270.0 180.0 130.0 82.0 60.0 37.0 26.0 14.0 8.9 6.8 4.5 1.7 16 /15 14 /15 12 /15 10/13 9/12 8/11 7/10 6/9 5/8 4/95 4/7 3.5/5 (19.5 kg) (13.9 kg) (9.8 kg) (5.7 kg) (4.8 kg) (3.0 kg) (2.2 kg) (1.4 kg) (0.92 kg) (0.77 kg) (0.55 kg) (0.23 kg) Sleeve unit no insert tapered KC3830 KC3826 KC3324 KC3168 KC3596 KC3164 KC3160 KC 3156 KC 3152 KC3148 KC3144 KC3998 and conversely if the natural feeder is too small... casting soundness Williams Cores The purpose of Williams Cores is to provide an aperture in the skin of the feeder so that the atmospheric pressure has access to the feed metal to 284 Foseco Non-Ferrous Foundryman’s Handbook ØD 1 ØD 1 H H Ød Ød Shape I (without flange) Figure 17.21 ØD 1 Ød Shape II (with flange) Williams Cores promote the feeding of the casting Williams Cores are supplied in a range... applied equally to moulds with a vertical parting, such as those made on the Disamatic moulding machine The sleeve pattern is divided – but off centre – one part being slightly smaller than the other The Feeding systems 283 D0 D01 x top R1 R8 M10 H1 H 60 x bottom DU H2 DU1 90° y bottom 120° y top Figure 17.20 Sleeve pattern for shell mould application two parts are mounted on opposite sides of the... remains on top of the feeder It is particularly recommended for use on feeders where rapid sculling takes place and where carbon contamination is to be avoided Feeders where FERRUX 16 is most often employed are in the diameter range 25–200 mm FERRUX 101 This is an exothermic anti-piping compound of medium sensitivity It is ideal for general steel foundry use on feeders of 150 mm diameter and upwards It... refractory ceramic Table 17.5 Application of breaker cores Breaker core material Casting metal Silica sand Silica sand Ceramic Chromite sand Chromite sand Steel Grey iron, s.g iron, non-ferrous metals Grey iron, s.g iron, non-ferrous metals Steel Grey iron, s.g iron Feeder diameter (mm) 35–120 35–300 40–120 80–500 200–500 Experience has shown that at least 70% of the breaker core area should be in contact... functional principle The floating sleeve patterns incorporate maximum feeder-neck dimensions applicable to iron castings For steel, light alloys and non-ferrous alloys, neck modulus can be modified to usual casting modulus equal to neck modulus For full details, refer to Foseco leaflets Shell mould application Sleeves may also be inserted into shell moulds The principle is the same as for green sand moulding, . THERMEXO. 286 Foseco Non-Ferrous Foundryman’s Handbook FEEDOL anti-piping compounds for all non-ferrous alloys The lower casting temperatures and the differing chemical requirements for non-ferrous. correct feeder. Foseco provides tables allowing KALMIN S feeders to be selected with the desired modulus, volume (capacity) and dimensions. 272 Foseco Non-Ferrous Foundryman’s Handbook KALMINEX. sleeve. Figure 17 .15 KALBORD jointed mats. 500 22 300 KALPAD board 1001 500 50 50 22 300 KALPAD jointed mat 1002 500 45 140 r=420 KALPAD pad 1012 278 Foseco Non-Ferrous Foundryman’s Handbook KALPAD