Application considerations forKALPUR for steel direct pour units.

V O L U M E 1 I S S U E 1

Pouring steel castings directly down a riser has never been a desirable means of achieving a high level of casting quality– until now. Foseco’s patented

KALPUR* for steel technology is one ofthe fastest growing innovations in thesteel foundry industry. The KALPUR forsteel unit – an integrated insulating risersleeve and filter – provides clean, less-turbulent metal flow to the mold. Thisgreatly reduces casting inclusions andimproves casting surface finish, helpingthe foundry reduce welding and repaircosts. Removal of conventional gating systems

reduces the thermal gradients in the mold,improving both the casting surface

finish and the metallurgicalconsistency through a moreuniform casting density.

The performance ofKALPUR for steel directpouring units is greatlyinfluenced by the fluidity

of the metal being filtered and the method bywhich the metal is poured. Metal fluidity is affectedby a variety of critical, and often hard to controlfoundry variables, such as: metal temperature,

metal chemistry, and inclusion level(oxides of residual elements such as Al,Zr, Fe). Pouring rates vary widely bypouring method. Flow rates from mostteapot ladles, over a course of a heat,vary less significantly than those ofmetal from bottom-pour ladles, simplybecause of variance in ferro-static head

pressure in the ladle. No matter what themetal grade, metal temperature, pouring method,

or inclusion level, the KALPUR for steeldirect pouring unit must remain nearly full duringpouring. If your ladle pouring rate capacityexceeds the potential flow rate of the filter, keepingthe unit full should not be a problem. If your ladlepouring rate capacity is less than the potential flowrate of the filter, it will be more difficult to keep thecup full and filter breakage becomes more likely.

In applying the KALPUR for steel unit to the casting, the engineer is encouraged to take the following steps to optimize performance.

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©Consider the feeding requirements for the castingsection that is fed by the KALPUR for steel unit:First, determine the sleeve diameter and heightthat makes sense for the application. Then, checkthe KALPUR for steel Product Data Sheet forsleeve dimensions and riser modulus values incalculating the optimal size KALPUR for steeldirect pouring unit.

©Consider which type of KALPUR for steel unit will beapplied. For most ram-up applications, free-formedsleeves work best because the rough outer surfaceof the sleeve prevents it from floating up from themold cavity during pouring. However, if moldingwith a jolt-squeeze table using green sand, considerusing KALPUR for steel inserts. The inserts cannotbe crushed during the molding cycle since they areinserted into the mold after the molding operationis complete. KALPUR for steel inserts are manufac-tured with a controlled outer surface dimensionwhich ensures consistent feed performance. To

prevent sleeves from floating during pouring, securethem to the mold using molding nails.

©Next, consider the desired contact area in selectingthe sleeve. KALPUR for steel RND (Round-Neckdown)units provide reduced casting contact area, comparedto conventional KALPUR for steel tube-shapedsleeves. An integral break-off notch formed in theRND unit promotes easy riser removal.

©Place the sleeve in a location desirable for feeding,as close to the casting surface as possible to mini-mize the distance the metal has to fall in the moldand to prevent high-velocity impingement on themold surface or cores.

©After determining the size of the KALPUR for steelunit required to feed the casting, determine the sizeof filter necessary to provide sufficient metal to themold in terms of flow rate and flow capacity. Again,reference the KALPUR for steel Product Data Sheetfor flow rate and flow capacity data. It is helpful to

quantify, in advance, the flow rate capacity of theladle being used to fill the mold cavity before proceeding.

© If the filter contained in the KALPUR for steel unit willnot allow for the required flow rate to be achieved,increase the diameter of the unit (in inches) until youachieve the desired mold fill rate. If the flow rate orflow capacity rating exceeds your capability to pourmetal, the casting may not be suitable for direct pouring.

© If your casting or section requires a larger feeddemand than any KALPUR for steel unit is able toprovide – even if the filter is able to provide suffi-cient flow rate and flow capacity – the casting maynot be suitable for direct pouring.

©Develop a clear understanding of your foundry’sflow rate capacities before applying ANY directpouring unit. The flow rates (and velocity) of metalfrom bottom-pour ladles varies significantly over thecourse of a heat. This needs to be considered in anydirect pouring application.

Applications requiring specialconsideration:© Any stainless steel application. Since thefluid metal is generally poured well above itsliquidus temperature, and since stainless steelby its very nature contains fewer elements ofreoxidation, filters prime almost immediately.Consequently, pourers often find it difficult to keepKALPUR for steel units full of metal when pouringstainless steel.

© Applications pouring from small teapotor lip-pour ladles where it is difficult to keepthe KALPUR for steel unit full of metalduring filling. This is particularly a problem withsmall teapot or lip-pour ladles. The flow ratecapacity of the ladle must exceed the flow ratecapacity of the direct pouring unit.

© Applications pouring from large bottom-pour ladles where the metal velocity and flowrate are high at the beginning of a heat.While bottom-pour ladles generally provideenough metal to keep the KALPUR for steel unitfull of metal during filling, the initial impact of theimpinging metal stream can sometimes result inbroken filters. Again, this can be particularly critical when pouring very fluid metal such asstainless steel where filter priming is immediate,

causing the filter to remain exposed directly to theimpinging metal stream, with little to no build-upof metal head above the filter component.

© Any application where the distancebetween the pouring lip or pouring nozzleis greater than 12 inches. This condition isgenerally limited to large teapot ladles where it is

difficult to maintain close proximity between theladle’s pouring lip and the top of the KALPURfor steel unit; particularly early in the heat whenthe ladle is full.

© Any application where the metal isnot fluid. Typically, KALPUR for steel units canbe readily applied as long as the metal tempera-ture remains at least 100° above liquidus andthe metal is relatively clean. Dirty metal, typicallyas defined by the amount of oxides in the metal,can easily block filter pores and lead to prematureblockage of flow. Foseco strongly recommendsKALTEK* ladle linings in any application withdirect pouring. KALTEK linings effectively improvemetal fluidity by reducing the level of residualelements brought about by dirty ladles, andwill maintain pouring temperatures over anarrow range.

Foseco encourages its foundry customers toevaluate new direct pouring applications withKALPUR for steel units over the entire range ofmetal fluidity and pouring rates before convertingthe casting to KALPUR for steel units. Please contact your Foseco Account Executive for advicein applying KALPUR for steel units. Our experi-enced Product Applications Managers are alsoavailable to answer your questions.

KALPUR for steel RND.

In recent years the steel foundry indus-try has benefited greatly from Foseco’sdirect pour technology. This technology

has resulted in significant yield improvements,reduced defects, and improved metallurgicalconsistency.

KALPUR for steel tubes have a fixed feedvolume and flow rate capacity and a large contactsurface making the tube-shaped unit ideal for sideriser applications. However, when a castingrequires a large modulus or feed volume,and when contact area on the surface of thecasting is limited, it may not be economicalto use KALPUR for steel tubes. To addressthese applications, Foseco has developedthe KALPUR for steel RND (RoundNeckdown) unit. This innovative new shapeexpands the Foseco line of KALPUR forsteel units to a more extensive range ofcastings.

In selecting a direct pour unit for a givencasting, three criteria must be considered: feedingcapacity, filter capacity, and flow rate. Does thesleeve contain enough modulus and volume tofeed the casting or section? Does the filter size

provide enough filtration capacity for the pouredweight? And, is the flow rate through the filter suf-ficient to pour the casting within the optimumtime? If any of these criteria are not met, the nextlarger size KALPUR for steel unit should be used.

For those castings requiring a higher feedvolume but not a large flow rate or filter capacity, the answer is the new KALPUR for steel RND unit

which combines a larger feed volume than thatof the tube direct pour unit with flexibility infilter size. The RND shapes provide a feed metalvolume of 100-350 cubic inches and a filteringcapacity of over 1000 pounds.

The KALPUR for steel RND unit is a free-formed insulating riser sleeve with a notchformed at its base to create a knock-off point. Thiseliminates the need for breaker cores and allowsfor lower cleaning costs.

In addition, the lower portion of the KALPURfor steel RND unit has seats for two consecutivefilter sizes, making it more versatile – and incertain applications more economical – than

KALPUR for steel tubes. This design allowsfor a wide range of feed requirements in avariety of casting geometries.

KALPUR for steel RND units shouldbe considered for castings or sections thatrequire a larger volumetric feed demand,due to casting size or alloy, than is offeredwith the standard direct pour units. Also,where it is difficult to find a flat area wherea full contact sleeve of the proper modulus

or volume will fit, reducing the contact area allowsthe riser to be located over a smaller area, enablingthe reduction or elimination of padding. KALPURfor steel RND units can also be used in applica-tions where a standard round neckdown risersleeve is currently being used to feed the casting.

Application considerations for KALPUR for steel direct pour units. Continued from front...

KALPUR Contained Volumefor steel Modulus Weight (lbs.) (In3)

RND

(4 x 1.8 x 6) .92 10.5 42.6

(5 x 2.4 x 8) 1.20 23.8 95.3

(6 x 3.0 x 10) 1.44 45.9 185.7

(7 x 3.5 x 12) 1.70 80.2 325.0

any foundries have come to realize significant savings and improvedquality through the

introduction of the KALPUR forsteel direct pouring system.KALPUR for steel units havebeen used with many highproduction moldingsystems. Among themost demandingof these moldingsystems have beenjolt squeeze mold-ing applicationswhich require thefeeding unit to with-stand high molding pressureswithout breakage. Until recently, this has presenteda unique challenge to the molder when applyingKALPUR for steel units.

As with most tasks, the job is made easier ifyou have the right tools. Foseco has recognizedthe challenge and, in response, developed mold-ing plugs for jolt squeeze and conventional mold-ing applications.

Made from highly resilient epoxy resin, themolding plugs will stand up to the most demand-ing molding operations and allow KALPUR forsteel direct pouring units to be molded in place.All molding plugs are cast to exact dimensions,ensuring a reliable fit inside all of the KALPUR forsteel direct pouring units. The molding plugs alsofeature an integral dirt trap that forms a shallowring around the outer circumference at the top ofthe KALPUR for steel direct pouring unit. Thisshallow ring is designed to retain stray sand par-ticles, preventing them from entering the moldcavity. Used in combination, the molding plug anddirect pouring unit produce cleaner castings.

Molding plugs are available to fit the full rangeof KALPUR for steel direct pouring units. They

are available individually oras a set to suit your particularrequirements. The productcodes and descriptions areoutlined in the accompany-ing chart.

Foseco has also devel-oped a filter insertion tool set

for KALPUR for steel units. This setfeatures a filter insertion disk suitablefor use with each of the KALPUR forsteel direct pouring units. The filterinsertion tool goes where fingers

often cannot reach, seating the filterwithin the KALPUR for steel direct pour unit.

The insertion tool set will save time and pre-vent difficulties associated with incorrectly seatedfilters. Simply place the selected filter in theKALPUR for steel direct pour unit. Using theappropriate insertion tool, press down gently onthe filter, seating it into the direct pour unit. A lighttap with the plastic-tipped hammer ensures the filteris seated and fully engages the holding strips.

KALPUR for steel direct pouring units areproven to be the best solution for many castingjobs. Now with Foseco’s new molding plug andinsertion tools, they are even easier to apply tomany castings.

Your Foseco sales representative can providefurther details regarding molding plugs and inser-tion tool sets. Don’t hesitate to discuss theseunique products at your next meeting.

KALPUR for steel molding plugs and filter insertion tools.

M asting surface finish can be improved

using the KALPUR for steel direct pouring

process. The process allows for more uniform

casting temperatures in the mold after pour-

ing. Fewer inclusions enter the mold, and

a less turbulent metal stream results in

fewer inclusions generated in the mold. Mold

filling times are dramatically reduced.

To illustrate this point, the WCC grade

casting on the

left was poured

using conventional

gating practice. A

popular flow and solidification modeling

program was used to model the casting

before it was

poured, in order

to optimize mold

filling and feed

performance. The same casting shown

on the right, when poured using a KALPUR

for steel direct pouring unit, had markedly

better surface finish.

KALPUR for steel units improve steel casting

surface finish.

C

Molding plug and filter insertion tool setsfor KALPUR for steel direct pouring units

Product Code Description Size

223100 Molding plug 2.0 x 6.0

321450 Molding plug 2.5 x 6.0

415700 Molding plug 3.0 x 6.0

515950 Molding plug 4.0 x 6.0

145350 Molding plug 5.0 x 8.0

423350 Molding plug 6.0 x 9.0

528200 Molding plug set of 6 2.0 x 6.0 through 6.0 x 9.0

158100 Filter Insertion tool set

any steel foundries use jolt-squeezemolding equipment for making greensand molds. With the right toolingand a few additional steps shown in

the photos, it is easy to to use the KALPUR for steelDirect Pouring Process when using jolt-squeezemolding equipment. The obtainable benefits includeincreased yield, higher pattern plate utilization, andcleaner castings, to name a few.

Figure 1 shows the cope patternplate mounted on the moldingmachine. The orange post on thebackground is a loose-piece vent. TheKALPUR for steel unit will be rammedup in the mold on the pad (left side ofcasting). Since the unit effectivelyfunctions as a gating system and anactive feeder, the pad supporting theunit is raised above the parting line bythe height of the feeder neck. Beforeplacing the filter component in thesleeve of the KALPUR for steel unit,the sleeve component is placed on thepattern, then a molding plug is placedin the sleeve. Figure 2 shows the copepattern with the unit and the moldingplug in position. The flask is positionedready for sand filling.

Molding plugs are available in sizesto fit the KALPUR for steel units. Thespecially designed plugs keep sand out

of the sleeve during filling and also protect thesleeve from being crushed by the squeeze head.

The mold is filled with sand. The molder exercisescaution so as not to tip the KALPUR for steel unit.Sand is hand-tucked around the unit (Figure 3).

After the jolt-squeeze cycle is completed, themolder cuts the sand away from the top ofthe molding plug (Figure 4) and lifts it from themold (Figure 5). Using a slick, the molder shapes

the sand in the form of a basin above the sleevecomponent. The cap on the top of the plug makesa “gutter” around the top of the sleeve to keep anyloose sand from falling into the mold cavity.

The final step before mold closing is to insertthe filter in the unit. The filter insertion tool makesthis step easier, as shown in Figure 6. Notethe smooth opening in the sand above theKALPUR for steel sleeve.

Using KALPUR for steel on jolt squeeze molding equipment.

M

A N E W P E R S P E C T I V E O N P E R F O R M A N C E

Figure 2Figure 1 Figure 3

Figure 5Figure 4 Figure 6

Foseco, Inc. Foseco Metallurgical Inc ● 20200 Sheldon Rd. ● Cleveland, Ohio 44142 ● Phone: 440-826-4548 Printed in the U.S.A. © Foseco, Inc. 1997 1M/1297

All rights reserved. No part of this publication may be reproduced, stored in a retrieval system of any nature or transmitted in any form or by any means, including photocopying and recording, without the written permission of the copyright holder.All statements, information and data contained herein are published as a guide and although believed to be accurate and reliable (having regard to the manufacturer’s practical experience), neither the manufacturer, licensor, seller nor publisherrepresents or warrants, expressly or implied: (1) their accuracy / reliability (2) that the use of the product(s) will not infringe third party rights (3) that no further safety measures are requested to meet local legislation. The seller is not authorized tomake representations nor contract on behalf of the manufacturer/seller. All sales by the manufacturer/seller are based on their respective conditions of sale, available on request.

*KALPUR and KALTEK are Trade Marks of the Foseco Group of Companies.

Feeding Systems Facts are intended to promote the exchange of information,to contribute to the fund of available knowledge in the foundry industry and to promote

good feeding system practice. Foseco will also use Feeding System Facts tohighlight new products and concepts and to provide application tips and guidance.

KALPUR direct pouring units are coveredby U.S. patents #4,928,746 and 4,961,460and Canadian patents #1,304,599;1,304,560; 1,304,561; and 1,304,562.

KALTEK ladle linings are covered byU.S. patent #4,330,107 and Canadianpatent #1,195,472.