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Research

Leading steel casting research has been a cornerstone of SFSA for more than a century. The Society’s portfolio of research programs are devoted exclusively to steel castings. Topics are influenced by the various research committees and research is conducted at leading universities with experts in areas like modeling, melting, heat treat, and material development.

SFSA members have exclusive access to research results through the steel casting wiki, technical meetings and the annual T&O conference.

Projects

  • Effect of Cooling Rate on Austenite/Ferrite Ratio, Iowa State University – Scott Chumbley
    • CD3MWCuN is a super duplex stainless steel used in corrosive environments. This two-phase microstructure gives this alloy a good combination of mechanical properties and corrosion resistance. Due to tightening specifications on allowable ferrite content, control of these two phases during melting has become increasingly critical. Schaeffler diagram has been used to predict the amount of austenite and ferrite in stainless steels based on chemistry; however, this plot was developed for welds. This project aims to develop a similar diagram based on variations of cooling rate from the homogenization temperature. The effect of the major alloying elements – chromium, nickel, molybdenum – on the microstructure will also be investigated. The CD3MWCuN composition will be varied by ±10% Cr, Ni, Mo and the ferrite content will be measured.
  • Cold Spray, Iowa State University – Scott Chumbley
    • In some instances, small porosities are found on sealing surface of castings after machining. When this happens, castings need to be welded and reheat treated for them to be accepted. However, if the casting cannot be reheat treated without compromising its properties, the casting is scrapped instead. This project recognizes the potential of cold spray in salvaging castings and minimizing scrap in foundries. Cold spray is a relatively new technology that is used to deposit material as a coating or to fill up cavities for dimensional restoration and surface quality improvement. This method seems to be a viable technique to fill up small surface porosity on a sealing surface and other minor surface indentations.
  • Digital Surface Standard, Iowa State University – Frank Peters
    • Current standards for inspection of cast metal surfaces use qualitative methods leaving room for variation in interpretation of the standard. Standards used in the metal casting industry are the Alloy Casting Institute (ACI) Surface Indicator Scale, Manufacturer Standardization Society (MSS) SP-55 Visual Method, and American Society for Testing and Materials (ASTM) A802 that reference the Steel Castings Research and Trade Association (SCRATA) comparator plates. Some surface roughness inspection processes use the GAR Electroforming Cast Comparator C9. Other standards include ISO 11971 and BS EN 1370, which overviews SCRATA and BNIF, and ASTM A997 for investment castings. Digitizing the process will make the inspection more repeatable and reproducible and will help avoid confusion between the foundries and their customers. This will also help foundries verify visual inspection results internally or promote automation of the inspection qualification process.
  • Manufacturability Analysis Software Development, Iowa State University – Frank Peters and Matt Frank
    • Designs created by design engineers often meet the functional requirements but fail to meet the manufacturability constraints. Currently, feedback from a potential manufacturer is often too late in the design process. A software (3D Integrated Feedback, 3DIF) is being developed that will provide early-and-often feedback to designers that will guide them in designing the component to have more manufacturable characteristics in general which will reduce procurement costs and time.
  • Hybrid Manufacturing (Metal Printing), Iowa State University – Frank Peters
    • ISU is investigating the potential of hybrid metal casting in producing steel components. Lased Engineered Net Shaping or LENS uses a focused laser to melt metal powder and build metallic layers on a substrate. Possible uses of this process are to create features that are difficult to cast, to do last minute product differentiation, to create features after machining, and to build gradient materials.
  • Welding of High Strength Steels, Lehigh University – John DuPont
    • The goal of this project is to establish welding procedures for restoring the strength and impact toughness of welds on cast high strength steels (precipitation hardened (PH) stainless steels 17-4 and 13-8+Mo, cast Eglin steel (CES), and AF9628). Research involves microstructural characterization, mechanical testing, and thermodynamic and kinetic modeling. Methods for optimizing weld properties of PH grades when post-weld heat treatment is not possible are also being investigated. The idea is to use the thermal cycles from subsequent weld passes to control the strengthening precipitates.
  • Welding of 10wt% Nickel Steel, Lehigh University – John DuPont
    • Steels for navy applications require high strength and good low temperature toughness. This project is examining the phase transformations and mechanical properties in the heat affected zone of 10wt% nickel steel welds.
  • Quench Sensitivity of AF9628, Missouri University of Science & Technology – David Van Aken
    • AF9628 is a high strength low alloy steel that is being used in military applications. Proper heat treatment of this alloy is critical in achieving properties. This study is investigating the effect of cooling rate from the austenitization temperature on properties. This would help identify if there is a critical quench rate for this alloy and if it is prone to auto-tempering.
  • Cast Preforms for Forging, University of Alabama at Birmingham – Robin Foley, Charles Monroe, John Griffin
    • Many forgings have long lead times and high costs because the stock is unavailable or is poorly shaped to produce the final forging. A cast preform allows material to be positioned to get the forging shape and properties efficiently.  This project will determine the forging reductions for cast steel preforms to realize the required properties of a forging. The goal is to reduce the reduction ratios and still meet the required forging properties. Another application of this project is to further improve properties of some castings like ground engaging tools by forging critical areas of the castings. The use of cast preforms would expand the supply chain for low volume forged components since foundries can melt and cast in smaller batches.
  • Automatic Risering, University of Alabama at Birmingham – Robin Foley, Charles Monroe, John Griffin
    • This tool is being developed as part of the casting module in ISU’s Manufacturability Analysis Software. This risering tool aims to provide a quick feedback to designers or to help with cost estimation.
  • Data Acquisition, University of Alabama at Birmingham – Robin Foley, Charles Monroe, John Griffin
    • UAB is working with Montana Tech on collecting data during pouring and filling of molds using thermocouples and borescope with filter in the mold to verify solidification modeling data.
  • Image Analysis Techniques for Digital Radiographs, University of Alabama at Birmingham – Robin Foley, Charles Monroe, John Griffin
    • UAB is developing an image analysis tool to rate digital radiographs and verify relationship between mechanical properties and maximum indication length. This maximum indication length will be determined using the radiography test (RT) standard developed by University of Iowa.
  • Microstructural Characterization of High Strength Steel, University of Alabama at Birmingham – Robin Foley, Charles Monroe, John Griffin
    • Cast Eglin steel (CES) and AF9628 are high strength low alloy steels that have about 230ksi tensile strength and 11% elongation. Consistently achieving the ductility in castings has been challenging. Minimizing microporosity is critical in these alloys. UAB has developed a technique in measuring the microporosity in these castings. It was also found that achieving high cooling rates is important in optimizing properties of these alloys. UAB characterizes this effect on microstructure by measuring the secondary dendrite arm spacing and the grain size.
  • Steel Quality Index, University of Alabama at Birmingham – Robin Foley, Charles Monroe, John Griffin
    • Metal quality index has been used in the aluminum casting industry in determining the reduction in quality from a process change or to evaluate a better performing alloy for a certain application. This quality index is calculated from the ultimate tensile strength and elongation. Using historical data from various heats of steel castings, UAB is proposing a steel quality index that would serve as a metric of the mechanical property performance. It was found that the reductions in quality index seemed to be correlated to melt cleanliness and indications found in the tensile samples. Establishing this quality index will provide an easy evaluation of new alloy systems and improvements done by the foundry in their casting practice.
  • Dimensions and Distortion, University of Iowa – Christoph Beckermann
    • Current casting simulation software fails to accurately predict final dimensions, distortions, residual stresses, and cracks in steel castings. This research aims to develop modeling algorithms for reliable dimension and distortion predictions in steel casting. Mechanical property datasets for mold and metal are being developed and simulations are validated with casting trials. The goal is incorporate these modeling algorithms to solidification software used by foundries.
  • Process Modeling of High Strength Steel, University of Iowa – Christoph Beckermann
    • The objective of this research work is to provide advanced modeling capability for casting process design and performance prediction of high strength steel (cast Eglin steel and AF9628). Refinement of the model involves correlation of solidification simulation predictions to experimental data on mechanical properties and microstructural analysis.
  • Counter-Gravity Sand Casting of Steel with Pressurization During Solidification, University of Iowa – Christoph Beckermann
    • This research aims to develop sand casting process that would produce castings that meet or exceed the performance of current state-of-the-art high performance forged components. The counter-gravity filling would eliminate defects such as air entrainment and mold erosion that may be found in traditional gravity-poured castings. The pressurization during solidification would potentially reduce the centerline shrinkage in steel castings.
  • Porosity in Manganese Steel, University of Iowa - Christoph Beckermann
    • Current porosity prediction algorithms in commercial solidification software do not work well for manganese steel castings. The goal of this project is to develop a model for improved predictions of surface shrink and internal macroshrinkage and microshrinkage in manganese steels. Gas porosity was excluded in this study. Accurate mold and steel datasets will be developed.
  • Air Entrainment, University of Iowa - Christoph Beckermann
    • Steel cleanliness still remains a major challenge in the steel industry. It was found that reoxidation inclusions are the major source of these inclusions. Reoxidation is the reaction of elements in liquid steel with oxygen after the molten steel has been deoxidized. Air entrainment during pouring is the main cause of reoxidation inclusions. SFSA’s Clean Steel program during the 1980’s and 1990’s has investigated the factors that affect air entrainment by conducting water modeling and several casting trials. University of Iowa (UI) is now developing a computational modeling tool that would predict the amount of air entrained during pouring. The experimental data acquired from the previous water modeling trials were compared to the results generated by the UI model. This modeling tool would help design and evaluate gating systems of steel castings.
  • Core Gas Pressure Evolution, University of Northern Iowa – Jerry Thiel
    • Using experimental data, simulation tool can be developed that can predict gas evolution in chemically bonded sand. Based on simulations, a gas pressure curve can then be established at every point within the mold or core. Using previous research by Charles Bates, gas pressure results can be compared against a threshold value to predict problem areas in castings. Temperature and pressure can be predicted using simulation software which can then be used in a user algorithm. To develop and refine the model, experimental trials is being done on aluminum castings since most published research on gas porosity defects are for aluminum alloys.
  • Predicting Dimensional Accuracy of Sand Castings, University of Northern Iowa – Jerry Thiel
    • This research will develop a modeling tool in predicting dimensional changes occurring in sand as a function of temperature. Silica sand with different levels of zircon will be compared. An API code will be developed and field trials for both constrained and unconstrained sections will be conducted. On-going field trials involve shell and no-bake sand molds.
  • Effect of Water Quality on Green Sand Properties, University of Northern Iowa – Jerry Thiel
    • Water-soluble salts are some of the mineral contaminants found in tap water used by foundries for their green sand systems. It was found in previous research that an increasing amount of these salts decrease the wet tensile strength of green sand. Several water samples have been collected from several places in the US and examined to determine the type and amount of salt concentrations. A Design of Experiment was established using the four predominant salts found, sodium, calcium, magnesium, and chlorine, as the factors. The effects of the wet tensile strength, compression strength, and shear strength were determined.
  • Characterization of Ceramic Aggregates for Green Sand Properties, University of Northern Iowa – Jerry Thiel
    • This project aims to evaluate non-silica alternatives to accommodate the tightened silica regulations that will be imposed on steel foundries. Ceramic aggregates are being characterized for their green sand properties and compared to a 55 GFN silica sand. Thermal expansion tests were conducted to measure their expansion characteristics.
  • 3D Printed Sand Thermophysical Properties, University of Northern Iowa – Jerry Thiel
    • UNI is characterizing thermophysical properties of 3D printed sand for use in process simulation software. Two different silica sand bonded with furan are being evaluated. Samples are being printed in x, y, and z orientations to evaluate the effect of orientation on sand properties.
  • Improving Surface Roughness and Resolution of 3D Printed Sand, University of Northern Iowa – Jerry Thiel
    • UNI is optimizing their sand printing capabilities by improving the surface roughness and resolution of 3D printed molds. The resolution of 3D printed sand is already comparable to investment castings but the RMS similar to investment castings still cannot be achieved.

Project status summary

Research ProjectUniversityProfessorStart DateEnd Date
Effect of Cooling Rate on Austenite/Ferrite RatioIowa State UniversityS. Chumbley Sep-14Aug-17
Cold SprayIowa State UniversityS. Chumbley Jan-15-
Digital Surface StandardIowa State UniversityF. Peters Jan-15-
Manufacturability Analysis Software DevelopmentIowa State UniversityF. Peters Feb-16-
Hybrid Manufacturing (Metal Printing)Iowa State UniversityF. Peters Feb-16Aug-17
Welding of High Strength SteelsLehigh UniversityJ. DuPont May-12Dec-17
Welding of 10wt%Ni SteelLehigh UniversityJ. DuPont --
Quench Sensitivity of AF9628Missouri Univ of Science and TechD. Van Aken Sep-16-
Cast Preforms for ForgingUniversity of Alabama at BirminghamC. Monroe, R. Foley, J. Griffin Oct-15Sep-20
Automatic Risering (part of ISU Manufacturability Analysis Software)University of Alabama at BirminghamC. Monroe, R. Foley, J. Griffin Feb-16Jan-17
Image Analysis Techniques for Digital RadiographsUniversity of Alabama at BirminghamC. Monroe, R. Foley, J. Griffin Oct-16-
Data Acquisition (w/ Montana Tech)University of Alabama at BirminghamC. Monroe, R. Foley, J. Griffin --
Microstructural Characterization of High Strength SteelUniversity of Alabama at BirminghamC. Monroe, R. Foley, J. Griffin 2013-
Steel Quality IndexUniversity of Alabama at BirminghamC. Monroe, R. Foley, J. Griffin --
Dimensions and DistortionUniversity of IowaC. Beckermann Apr-12Sep-17
Processing Modeling of High Strength SteelUniversity of IowaC. Beckermann 2012-
Counter-gravity Sand Casting of Steel with Pressurization During SolidificationUniversity of IowaC. Beckermann Mar-14Mar-17
Porosity in Manganese SteelUniversity of IowaC. Beckermann Nov-12-
Air EntrainmentUniversity of IowaC. Beckermann --
Core Gas Pressure PredictionUniversity of Northern IowaJ. Thiel --
Predicting Dimensional Accuracy of Steel CastingsUniversity of Northern IowaJ. Thiel --
Effect of Water Quality on Green Sand PropertiesUniversity of Northern IowaJ. Thiel --
Characterization of Ceramic Aggregates for Green Sand ProperUniversity of Northern IowaJ. Thiel --
3D Printed Sand Thermophysical PropertiesUniversity of Northern IowaJ. Thiel --
Improving Surface Roughness and Resolution of 3D Printed SandUniversity of Northern IowaJ. Thiel --