Starting a new relationship with a foundry is more than an investment in time and money to get patterns and tools over to them. The new foundry partner will also have to match your alloy specifications, which can feel like starting from scratch between your engineering team and their metallurgists. Not all foundries are equipped with the processes or skillsets to introduce a new alloy.
4 Critical Questions to Ask Before Moving an Alloy to a New Foundry
Stainless Foundry & Engineering pours more than 250 alloys – some we have introduced ourselves to expand our customer product base and some we create specifically targeted to particular customer specifications. One example would be narrowing in the carbon, chrome, or nickel content to give superior performance – that is quite common for us. The following are four critical questions we recommend asking a new foundry partner in order to gauge if they are the right fit.
1. Does this foundry have the capabilities and engineering skills your part requires?
Foundries will need to compare the chemistry and mechanical properties of your alloy when assessing if they can take your project on. Ask the foundry if they are used to making something similar – this lowers the risk of transferring your part over. If you can, get more information, such as whether similar alloys have given them problems and if they were able to identify the source and correct it.
Strategizing to make a dimensionally compliant and volumetrically sound casting of a new material requires experience. When foundries have a 3D solid model STEP-File, they can utilize solidification software, such as MAGMASOFT, and will be able to develop a sound high integrity casting. But, if your alloy is not in their solidification software’s alloy catalog, the foundry will have to take a different approach and rely on past practice and experience.
2. What processes does the foundry follow for quality assurance?
Since the foundry is manufacturing a specific alloy compliant to your Purchase Order, begin with evaluating the material specifications and the quality programs you require the foundry to comply with, such as ASTM, ASME, NAVSEA, and EN/ISO, etc. In addition, the foundry will need to ensure that their special processes work in harmony with the necessary heat treatment, non-destructive testing (NDT) and welding codes.
For success in the short and long terms, we recommend that all attributes of the foundry’s work with your alloy be documented. From there, the foundry can create control procedures. Ask the new foundry partner if they develop data sheets to catalog all technical and general information about the alloy – they should contain aim/range chemistry, actual mechanical properties, metallurgical and physical constants, foundry engineering parameters, general microstructure, and general industry usage of the alloy. This will ensure consistency in quality.
3. What is the foundry’s metallurgical process?
There must be a serious discussion between you and the new foundry partner about the desired outcomes you are looking to achieve with the alloy. After deciding the desired specification, foundry control aims and ranges need to be established. Next, the foundry needs to develop material sheets to establish the heat that will be made. Finally, the desired microstructure needs to be addressed. The microstructure can be a result of microstructural balance with the chemical aims and the pouring temperatures.
The foundry should document and follow a melt practice every time they pour the alloy. Selecting the furnace, ladle type, material additions, and other variables need to be the same every time in order to get the same result. The same should occur with melting practices to keep the metal bath free of large inclusions, oxides, and other contaminants. It is important to know that the new foundry partner has the technical resources and expertise to sustain future pours of the same alloy.
4. How does the foundry inspect castings to ensure quality?
Inspection programs require a thorough understanding of a new alloy and its base material specification. You as the customer should expect tests and inspections to be performed, as well as acceptance criteria to ensure the produced parts meet your requirements. Below are a few common codes for testing and inspection.
Test Method
Visual Testing (VT)
Liquid Penetrant Testing (PT)
Radiographic Testing (RT)
Typical Use
General surface conditions and welds
Internal and external accessible surfaces and welds
All volumetric internal surfaces and features
For more details on SF&E non-destructive testing capabilities, click here.
Moving parts to a new foundry can be a risky endeavor. But the greater risk is staying with a foundry that is not living up to your quality or communication standards. If you would like more tips on selecting a new foundry partner, check out our first article in this series, 4 Critical Questions to Ask Before Working with a New Foundry, and contact our team directly at sales@stainlessfoundry.com.