Four Thermal Processing Problems and How to Avoid Them

Heat treating, brazing, and metal finishing operations are key to the ensuring performance of parts in all types of different applications. Without proper thermal processing, safety-critical parts such as seat belt components for cars, hot-section engine parts in airplanes, and firearms assemblies run the risk of failing in the field, which can put people’s lives (and your company’s future) in jeopardy. 

In this article, we’ll cover four of the most common thermal processing problems that commercial and captive heat treaters encounter, and how we safeguard against them here at Paulo.

Problem #1: Operator Error and Equipment Failure

Operating equipment using manual controls is inherently risky because of the opportunity for human error. If an operator forgets to adjust the temperature or other settings on their equipment, you might wind up with a batch of out-of-spec parts that may require reprocessing or that must be scrapped entirely. 

In addition, we’ve yet to find a piece of thermal processing equipment that can run forever without maintenance. If a furnace tends to “run cold,” for example, operators may dial up the heat more than the recipe calls for in order to achieve the desired temperature in the process. While this measure may provide a temporary solution to get parts through heat treatment, it poses problems of its own.

First, equipment that requires special handling in order to get it to function makes heat treaters’ processes less trainable for employees. Team members must have “tribal knowledge” of the equipment in order to successfully operate it. 

Next, by performing these stop-gap measures, operators may be overtaxing under maintained equipment, which shortens its lifespan and can potentially lead to unplanned downtime. If you’re working with a commercial heat treater, this unplanned downtime can result in longer lead times and less flexibility to help you with emergency or overflow orders.

Operators may also be tempted to overload equipment to increase productivity, which can lead to parts masking or failing to reach the austenitizing temperature. This is especially true for continuous equipment. The automated loading systems at Paulo prevent this from happening, ensuring that PPAP and first-run loading rates are adhered to every time.

Another way we prevent these errors is with our proprietary software system, PICS. PICS houses all equipment recipes and associates each set of parameters and specifications with a part number’s bar code. Parts at Paulo must be scanned in order to run thermal processing operations in a piece of equipment, and operators do not have the ability to override the controls. 

All part recipe parameters are housed in PICS, which is integrated with automated precision furnace control systems known as PUBS (Paulo Universal Batch System) and PBS (Paulo Belt System). Both of these technologies ensure furnace settings are accurate according to each recipe. They also measure furnace conditions throughout processing and will self-correct if the temperature or atmospheric conditions begin to fall out of range. If the conditions in the furnace cannot be quickly corrected, processing will automatically shut down and parts will be quarantined for further investigation by our quality team.

These safeguards prevent human error from spoiling your parts and also force our teams to adhere to best practices for proactively maintaining our heat-treating equipment. This helps us maximize uptime, yield consistent results across the entire system since all processes are run the same way, and help our customers with rush or emergency situations. 

Problem #2: Inefficient Scheduling

Efficient, strategic scheduling is important for heat treaters to master when it comes to maximizing throughput and delivering on tight turnaround times. Smart schedulers will take several factors into account, including the prioritization of upcoming orders and the furnace recovery time required in between each batch of parts.

For example, if an operation runs the batch of parts requiring the highest temperature at the beginning of the shift, they must wait for the equipment to cool down to the proper requisite temperature before processing the next batch. While this clearly causes much less downtime than equipment failure, when done repeatedly and at scale, inefficient scheduling can lead to longer lead times and equipment underutilization. Equipment underutilization can have an adverse effect on profitability, which for customers, can manifest themselves in price increases.

Schedulers at Paulo take a strategic view of upcoming jobs in each division using the PICS software, planning out each shift according to our customers’ needs while maximizing uptime for each piece of equipment. 

Problem #3: Variations in Raw Materials

Your thermal processor may be treating parts exactly according to the appropriate recipe, but they are still getting out-of-spec results. The root cause of this issue typically lies much farther up the supply chain. 

Casting houses and foundries, for example, are often working with multiple alloying elements when producing the material for your parts. Oftentimes, this process requires a human operator to mix materials together in a furnace, which can be tricky when the individual alloying elements have different melt rates. Additives such as magnesium, for example, are notoriously difficult to bring into solution with other metals. We’ve also seen some manufacturers simply switch materials without notifying their heat treating partner, which will always yield unexpected results.

These issues may not be discovered until your parts reach the heat treatment phase, and if the problem lies with the raw material to begin with, there isn’t much your thermal processor can do to fix it—and you’ll be in for production delays while you await new materials from your suppliers to make new parts. 

The key ways to avoid this issue are to first, always communicate with your heat treating partner when substituting raw materials so that adjustments can be made to your heat treatment recipe. If you’re receiving raw materials from another supplier, your heat treater should work to proactively identify trends in your hardness testing results that may indicate an issue with your raw material before it becomes a bigger problem. 

We use another piece of proprietary technology to monitor these trends in hardness data at Paulo: ResultsMAN. Short for Results Manager, this system is fully integrated with PICS and stores all hardness data in the same place as your thermal processing data and recipes. This helps our metallurgy teams in the lab identify drift in your results that may signal variations in your raw material. We’ve helped several customers correct issues farther up their supply chains by monitoring and sharing this data with them.

Problem #4: Out of Spec Parts Entering the Supply Chain

One of the worst outcomes that can occur after improper thermal processing is for the finished parts to be put into service in the field. This is especially problematic for safety-critical parts in the automotive and aerospace industries. It can lead to costly recalls, steep financial penalties, and worst of all, catastrophic accidents that injure end-users or cause loss of life. Many manufacturing companies would struggle to survive such a situation without significant adversity.

We understand how much trust you place in the hands of your commercial thermal processor. That’s why we’ve built so many safeguards into PICS to prevent this situation from occurring for parts processed at Paulo. Using a variety of different sensors and data collection equipment, we measure more data points than any other commercial heat treater. If improper temperatures or incorrect atmospheric conditions are detected during processing, the processing is automatically shut down and parts are quarantined until the issue can be identified and corrected.

In fact, these parts cannot be shipped out of our facility if they are under review for processing issues or out-of-spec results. Our system will not allow a shipping label to be printed until parts have been properly processed and passed testing according to our customer’s specifications. This allows our customers to gain peace of mind that their parts are being well taken care of, so they can focus on other important aspects of running their business.

Datagineering Prevents Thermal Processing Problems

Armed with PICS and the largest team of metallurgists of any North American commercial heat treater, Paulo is best equipped to handle your critical parts. Our datagineering approach has led to success for many leading manufacturers in the world’s most demanding markets. Are you looking to level up your thermal processing results? Start a conversation with us today to learn more about how we can help you solve your toughest challenges when it comes to heat treating, brazing, and metal finishing.