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A coordinate measuring machine was used to measure the dimensions of cores and castings from the trials by the University of Northern Iowa.


modeling to accurately determine casting dimensions from room temperature pat- tern dimensions. Although a preliminary study, it provides the basis of future tools. As the ability of creating castings true to designs improves, reductions in machine stock can be made to decrease cost, im- prove reliability and speed production.


CONCLUSIONS Te research demonstrated that final


casting dimensions can be estimated us- ing accurate bonded sand thermo physi- cal property data and computer casting simulation. Tis specific case study utilized a phenolic urethane bonded core that lost the majority of its strength and integrity as its temperature was raised to that of the adjacent metal. Te loss of what is commonly referred to as retained strength, failed to provide restraint to the solid metals contraction. Tis is a very specific case where the core mass is low as compared to the metal’s mass and


heat input. Te results are also specific to the casting used for the experi- ments. Although the cases presented are restrictive, it provides solid insight into more accurate predictions of final casting dimensions based on mold- ing aggregates. Further studies will be undertaken to address large core mass and low metal mass situations where the core retains more strength and may restrict metal contraction. Te authors believe that this may


give insight to the causes and predic- tion of hot tearing defects in steel castings.


PRESENTATION Autonomous Optimization of


Gating and Risering Design for Steel Castings


AUTHOR Roy Stevenson, MAGMA Foundry


Technologies Inc., Schaumburg, Illinois


Table 1. Design Variable Ranges for Side Riser Optimization Design Variable


Contact Width Contact Height


Radius, top of Contact


Radius, Riser Base Sleeve Thickness Riser Height


Riser Base Height Riser Diameter


Lower Limit 20 mm


30 mm 12 mm


Radius, Bottom of Contact 12 mm Contact Length


12 mm 12 mm 0 mm


50 mm 60 mm 50 mm


54 | MODERN CASTING May 2016


Upper Limit 40 mm


50 mm 18 mm 18 mm 18 mm 36 mm 12 mm 75 mm 90 mm 100 mm


BACKGROUND Engineers have been using cast-


Step


10 mm 10 mm 6 mm 6 mm 6 mm


12 mm 12 mm 25 mm 15 mm 25 mm


Number of Steps 3


3 2 2 2 3 2 3 3 3


ing process simulation technology to design tooling and select process parameters for the steel casting process for years with the ultimate goal of meeting the required quality standards of the customer in the most cost effective manner. Te engineer- ing departments in steel casting facilities today are challenged more than ever from a resources standpoint due to short lead times, increasing quality requirements and shortages of qualified engineers. Te time it takes to evaluate potential tooling and process design options by manually simulating them using casting process simulation software will often exceed the time available to the engineer. Te presentation detailed a novel methodology that seeks to relieve the engineer of the time consuming labor involved in setting up and analyzing numerous different individual simula- tions. Te new methodology is re- ferred to as autonomous optimization and it greatly reduces the amount of time required by the software opera- tor to set up and analyze individual simulations by allowing the operator to run many different design pos- sibilities (i.e. using different cast- ing and tooling geometries and/or different process parameters such as pouring temperature or pouring time) from one setup without intervening to make any changes for the many


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