The A Team: Introducing a New Alloy Requires Inter-Departmental Process and Skill
Over the course of more than 75 years, Stainless Foundry & Engineering (SF&E) has built an impressive offering of 250 ferrous and non-ferrous alloys. Some alloys were added as a way for SF&E to broaden its reach within an industry or expand into a new one. Others were in response to a customer request.
Over the past four years, SF&E has introduced, revived, and grown seven alloys. In 2020, SF&E received the first order for white iron castings. Since then, orders have been rapidly growing with a focus on specialty pump castings. We also onboarded HK30Nb heat resistant stainless steel alloy in 2020 in both sand and investment while also receiving our first orders for Ni-Resist austenitic ductile iron to serve more customers in the aerospace market. SF&E continues to fine tune and enhance our knowledge of C96400 copper-nickel and Monel nickel-copper to accommodate growth in the military market. And we ramped up our brass and bronze casting offerings that SF&E was known for decades ago to meet new growing demand.
Adding or refocusing on an alloy and growing it slowly is challenging for any foundry. We’ve been able to do it several times per year for key customers, but it is no easy feat. SF&E takes a methodical approach that involves all departments. The following describes the contributions each department plays in delivering castings using new alloys.
It all starts with a pre-production meeting once a purchase order comes in, where experts from metallurgy, engineering, manufacturing and quality get together to solidify a plan of action.
“We review each other’s work as a group, including the gating system, the quality specs and standards, existing guidelines, and any Stainless historical documents related to the alloy,” said Javed Khokhar, Engineering Manager for SF&E. “The different cross section of knowledge assembled in the same room establishes a good interaction. It’s where some valuable suggestions develop.”
Everyone comes to the meeting with a different perspective – both on how to approach the project and to ensure they have the equipment, information and resources needed to complete it.
“Our pre-production collaboration helps us ensure that we have the right procedures to process the castings, the right welding documentation in place, NDT technology, and qualified personnel,” said Mike Porfilio, Director of Quality and Technical Services for SF&E. “Every contract has its own differentiation, so we have to make sure we have the right specifications on hand.”
With hundreds of alloys available through SF&E and three-quarters of a century in the business, in most cases there are foundational documents at the foundry, such as weld procedures, the team can reference. If the historical records are fairly old, engineers can clean them up to reflect the modern day. The team will also involve the customer in the collaboration if there are unanswered questions and, finally, schedule a test heat to verify manufacturability.
The SF&E metallurgy department is led by Vijay Talwar, Director of Metallurgy and Process. The first step in working with a new alloy for Talwar’s team is to understand the unique makeup of the alloy, how it handles high temperatures, and then develop guidelines for how to tap and pour the alloy.
“To produce sounds castings, we maintain tight control of process parameters such as time at temperature, final composition, and properties,” Talwar said. “These are a few of the many factors we control to influence the microstructure and properties, which is how we meet customer requirements.”
Internal procedures are developed, tested, and refined to ensure the pour is successful and the completed parts meet customer requirements. A successful pour is based mainly on the SF&E team’s ability to manage the multitude of variables between working with different materials.
“For example, high chrome alloys have a hardness of 600 BHN, compared to the 165 BHN hardness for stainless steel,” Talwar said. “Some alloys cannot be welded, so they require near-perfect casting. Others are brittle and can produce high scrap. We need to determine how to handle each material properly on a consistent basis.”
Khokhar leads foundry engineering for SF&E, so when a new alloy is introduced in his department, it is all about building new tooling and writing process guidelines. With all of the variables between alloys, introducing a new alloy means establishing a new production protocol.
Much of SF&E’s ability to cast new alloys is supported by the accumulated experience of the engineering and production team. Team members have had different career paths, some having worked with stainless steel, others with copper, iron, bronze, brass and nickel. They bring this knowledge to the table to help plan and troubleshoot. The use of 3D software MAGMASOFT® helps with the rest.
Once the team designs the tooling or pattern, they enter the computer drawing and the alloy specifications into MAGMASOFT to simulate the casting process using a 3D model. From there, they can analyze the pour and identify where shrinkage, porosity and inclusions may occur. MAGMASOFT also provides a recommended pouring temperature and chill time. SF&E uses all of this information to gauge and adjust the design until they are ready to move forward with the goal of a perfect pour, designed for manufacturability.
“We can produce good quality castings because we are vigilant in our training and in our guidelines,” Khokhar said. “With each casting we make, we continue to improve.”
The quality team, led by Porfilio, follows the casting process from the initial pre-production through to the final certification. The quality team ensures the entire production process adheres to standards from the American Society of Mechanical Engineers (ASME) and the American Society for Testing and Materials (ASTM). They also advise on heat treatment, welding capabilities, and what type of non-destructive testing (NDT) the alloy or material can endure.
“Some materials can be inspected by an X-ray, but some cannot. Others are better suited for magnetic particle testing, or liquid penetrate,” Porfilio said. “There are a lot of decisions that Quality has to make and then we write procedures around them and submit documents to the customer.”
From the pattern release, core making and molding, to the pouring, clean room, cutoff stage, removal of riser, dimension check, testing, and final approval, the Quality Management team is working in lock step.
“To meet the standards we need, requires lots of talented professional people,” Porfilio said.
A Welcome Challenge
There are a limited and shrinking number of domestic foundries with the capability to produce castings using many of the alloys in SF&E’s 250-plus list. It’s a challenge, but one SF&E enjoys taking on.
“We like taking these challenges head-on because we have the staff on hand and processes in place that have been refined over decades,” Talwar said. “Once we go through the new process and come out successful, we take extra steps to build confidence that we can produce the alloy at a high level.”
Not every foundry has the experience, equipment and production flexibility to introduce, revive, or grow an alloy. To find out how SF&E can meet your unique needs for quality castings, contact us at firstname.lastname@example.org.