The Anatomy of a Pour: SF&E Takes on High-Chrome Iron Casting

Stainless Foundry & Engineering (SF&E) is nearing the end of a multi-phase, multi-year operations throughput improvement project. The goal: maximum optimization for an above-and-beyond customer experience. Production efficiency efforts have focused on reducing lead times for commercial sand and investment castings, as well as high specification products, which we are well known for. But in 2019, when we were presented with a unique opportunity, we found our new processes could also aid in the development and launch of a new alloy.

Opportunity

In late 2019, we were approached by a potential new customer, sharing some challenges they were experiencing with a different foundry. The potential new customer detailed they needed someone to manufacture hundreds of different abrasion-resistant pump and valve parts for the mining industry.

“After many capability overviews and tours of SF&E, they alerted us of their strategy to move 100+ patterns in 2020 and spend $1,000,000. We were very excited, but we knew we had to lock in a process to satisfy producing that many new parts with a relatively new alloy,” said Mitch McCaffery, Director of Sales & Marketing.

SF&E has an expertise in pumps and valves. We had some past experience with high-chrome white iron, but nothing related to the volume this customer was detailing of introducing to our foundry. So, we got to work engineering a better pattern receiving and re-rigging process in the front end, as well as a top notch quality production process in the back end.

At the time, SF&E primarily poured carbon steel and stainless steel, which is a different setup – both in the lab and on the floor. This project was going to take some trial and error, expert analysis, and investment in iron-specific equipment.

The Formula

SF&E engineers and metallurgists started by reviewing and revising the customer’s patterns so they would have ideal rigging for iron. In preparation for making more irons, Mike Porfilio, Director of Quality and Engineering at SF&E, purchased a specialized spectrometer to analyze the cast irons, white irons, as well as certified reference materials to ensure we were pouring the material to the correct chemistry. The team came up with these tools to identify different ways to analyze the chemistry of the alloy and to continuously improve iron quality over time.

“White iron pours very nicely and creates low scrap,” Porfilio said. “It is easy to make if you can get the chemistry right and process it correctly.”

Once the team settled on a formula that would work, it was time to consider the molding.

The Molding

Since SF&E couldn’t process the iron castings like the other steel and stainless steel castings we primarily work with, we created a special process. It took trial, error, and continuous improvement as the team analyzed and dialed in the process.

The production team, led by Jesse Klema, Director of Operations for SF&E, facilitated introducing the use of breaker cores, different riser sleeves, and purchased an abrasive saw to improve front end efficiency. Soft plug inserts were put into the molds, prior to casting. This allows for machining bolt holes due to the hardness of this alloy, which is brittle and prone to cracking if not handled correctly.

The Pour

More improvement occurred during and after the pour. A major breakthrough was identifying that moving the molds too soon after a pour created negative results. Instead of pouring when SF&E production had gaps, we took a time slicing approach and now pour this alloy on a specific day of the week to let the molds sit for an appropriate time to solidify. This way, they are fully solidified prior to moving into the shake out area.

“The pouring process continued to improve and now it is a great alloy to pour. The cleaning time is less than regular castings and there is no welding needed – you just pour, clean, heat treat, inspect and the parts are ready to ship,” Klema said.

The Results

The SF&E team poured this alloy three times in 2019 prior to the new customer coming onboard. Since then, we have received and re-rigged 110 patterns, pouring high-chrome castings varying in size from 15 pounds to 1,600 pounds.

“Quality control is continuously improving, productivity is up, and high-chrome orders are now flying through the foundry,” Klema said.

With the production process optimized, the SF&E team is trained and ready to take on more customers with high-chrome cast iron parts.

“We are continuously honing the process to find better ways to make this and similar materials,” Porfilio said.

If you are experiencing a challenge with a pattern, or if you are interested in learning more about our high-chrome iron capabilities, contact us at sales@stainlessfoundry.com OR submit your request directly HERE.