Learn why heat treating is the lynch-pin to producing high quality stamped and formed part. Conversation taking place in a stamping plant somewhere in America: GM to Press Operator:   “What happened to the batch of prototypes you were supposed to have for me yesterday? The press was set-up three days ago to run them.” Press Operator:  “Better ask Quality. They were good to print when I last checked them.”

GM to Quality:   “Where are those prototypes I promised to ship to the customer yesterday? They have already called three times today.”

Quality Manager: I sent them to the heat treater, and you know how it goes. Sometimes the processing works on the first run and sometimes it takes a few runs to make it work.

GM to Quality:   “Well, how many runs is this one going to take? The customer is waiting for these parts, he needs answers now!”

Quality Manager: “They’re working on it…heat treating is causing movement in the material that wasn’t allowed for in stamping and forming. They said we should meet with them before we make dies and form parts, so they show us how to allow for movement in heat treating.”

This project stopped at heat treating because of minor distortion that was taking place when the parts were processed. Everyone involved in the project shared the frustration that was caused by an oversight -- the heat treater was left out of the production planning process.

All materials and product forms have hidden characteristics that when stamped can have differing results when processed through heat treatment. These characteristics are like players on a team who need to be considered in the planning and manufacturing of heat treated metal stampings. When the sequence of events, from design through heat treating, is viewed as a whole, and not as individual steps, the outcome can be a trouble-free experience. For example, the metal stamper knows intimately how the part takes a form, shears cleanly or springs back, or even oil cans. This critical information needs to be provided to the heat treater prior to processing parts.

A heat treater’s metallurgist knows the oven temperatures, soak steps, and sequence of events that must be performed so parts will meet the print requirements specified in the job order. In many cases, a heat treater may have even quoted the part, but re-occurring  thoughts of distortion control can quickly be forgotten when bickering over processing costs.

Many stampers have learned the value of meeting with a heat treater before the parts are stamped or formed resulting in a win-win situation for the stamper, heat treater and customer. Ultimately, there are no winners if a customer learns that his parts can’t meet print because, over the normal course of heat treating, the material moved due to stress caused in forming a 180-degree radius.

To prevent unforeseen problems from occurring at heat treating that can delay a job, add costs to processing to resolve the problem, or result in the parts not meeting print specs altogether, stampers should:

• Be forthcoming with all known information regarding materials that will be heat treated prior to asking a heat treater to provide a cost and a heat treating process for those materials;

• Plan in advance of stamping and forming parts to collaborate with an experienced heat treating company’s metallurgist who is certified and accredited to process materials that you are working with;

• Realize that heat treating is the lynch-pin to producing high quality stamped and formed parts, and leaving this critical process to chance can be a costly mistake.

The Actual Case Study:
Small parts were stamped and formed out of Beryllium Copper Alloy 172. The tolerances were not especially tight, but the parts needed to be gold plated after precipitation hardening. When the parts were formed around a tight radius to complete a 180-degree bend, they met print. During the heat treatment process, the material hardened to specification limits, but the action of forming the radius caused the form to distort. While it appeared the parts still met print with the slight amount of movement, the plating would not make complete coverage because of a gap that was caused by distortion that was too small for the plating solution to pass through. The die was adjusted, but inconsistencies in the material and response to processing did not resolve the problem. Phoenix Heat Treating then organized a meeting with their metallurgist and the stamping and plating companies to collaborate on the issue. It was agreed to plate the parts before heat treatment while the gap was still open, then process in a vacuum furnace to maintain the gold plate integrity. While processing costs increased slightly, the parts were salvaged and the customer was immensely pleased with the collaborative effort. Realizing that the linchpin in the manufacturing process - heat treating, had been left to chance, the stamper decided to begin collaborating with the heat treater on all future productions. He will then know how a material will react to processing, and allow for these changes in his dies and stamping. The manufacturing of stamped parts is a professional practice that requires collaboration and open communication with associate vendors.

For more information on how to work with a heat treater prior to manufacturing parts, you are welcome to contact Peter Hushek, president and metallurgist of Phoenix Heat Treating at: phushek@PHXHT.COM

More Or call Phoenix Heat Treating at 602-258-7751