August 2026 Volume 8

ENERGY

Tune Combustion and Reduce Excess Air For gas-fired forge and heat treat furnaces, burner tuning is one of the most practical and often overlooked opportunities. An incorrect air-to-fuel ratio can waste fuel, reduce temperature uniformity and contribute to scale formation. Excess air may appear harmless because it supports combustion, but heating extra air to forging temperatures consumes energy that does not add value to the part. DOE process-heating guidance identifies burner air-to-fuel ratio control, furnace pressure control, reduced air infiltration, improved insulation, preheated combustion air and waste heat recovery as major opportunities in industrial process heating. 3 For a forge shop, this translates into a practical checklist: verify burner setup, inspect oxygen-trim controls where applicable, repair door seals, check dampers, maintain pressure balance and make sure operators understand the cost of running outside desired furnace conditions. This is not just a sustainability measure. A properly tuned furnace can support better temperature control, more consistent production, less rework and lower fuel consumption. Plants should consider regular combustion audits, especially on older furnaces or equipment that has been modified over time. Capture Waste Heat Before Buying More Energy Waste heat recovery is another major opportunity in heat-intensive manufacturing. Fuel-fired furnaces, ovens, boilers and other thermal systems can send large quantities of usable heat up the stack. Depending on the process, recovered heat may be used to preheat combustion air, preheat incoming stock, heat wash water, support space heating, or serve another nearby process. DOE identifies waste heat recovery, load preheating using flue gases, preheated combustion air and using waste heat for external processes as process-heating improvement opportunities. 3 In a forge shop, the feasibility depends on exhaust temperature, cleanliness of the exhaust stream, operating schedule, available space and whether there is a consistent use for the recovered heat. A large-scale example comes from Cleveland-Cliffs. The company reports that at some of its integrated steel operations it recovers energy from by-product process gases to generate electricity. In 2024, Cleveland-Cliffs reported that on-site generation supplied approximately 75% of electricity needs at its Burns Harbor mill and nearly 100% at its Indiana Harbor mill. 4 Most forge shops do not have access to the same type of by-product gas streams, but the principle is relevant: energy-intensive manufacturers can reduce purchased energy by treating waste streams as potential resources. For forging operations, waste heat recovery projects may be more modest, but still valuable. Examples include recuperative burners, regenerative burners, stack economizers, billet preheating, charge preheating, heat recovery from quench systems, or using furnace exhaust for lower-temperature applications elsewhere in the plant. Consider Furnace Upgrades When the Business Case Is Broader Than Fuel Not every energy issue can be solved with tune-ups. Older furnaces may have outdated burners, poor insulation, slow recovery, weak controls, excessive leakage or uneven heating. In those cases, an upgrade may reduce energy use while also improving throughput, temperature uniformity, quality, maintenance and safety.

An example that is particularly relevant to forging is Cleveland Cliffs’ Butler Works project in Pennsylvania. The company announced that, if awarded DOE funding, it would replace two natural-gas-fired high-temperature slab reheat furnaces with four electrified induction slab reheat furnaces. DOE’s project description states that induction heating can reduce energy losses and provide precise temperature control. 5 A steel mill slab reheat furnace is not the same as a forge shop billet furnace. Still, the example is useful because it shows that major steel manufacturers are actively evaluating advanced heating systems not only for emissions reduction, but also for energy efficiency, process control and production competitiveness. For forging producers, the furnace upgrade conversation should include more than fuel savings. A strong business case may also include reduced scale loss, better yield, fewer rejects, faster heat-up, improved safety, lower maintenance costs and improved ability to meet customer sustainability expectations. Use Electrification Selectively Electrification is not a universal answer for forging, but it deserves a serious and practical look in selected applications. Induction billet heating, electric heat treat equipment, resistance heating and hybrid systems may offer advantages depending on part size, material, production volume, utility rates, demand charges and available electrical infrastructure. Induction heating can be attractive because energy is delivered directly into the workpiece, heat-up can be fast, and equipment can often be turned down or shut off more easily than large gas-fired furnaces. It may also reduce floor heat and improve temperature control. However, electrification must be evaluated carefully. Plants need to understand peak demand costs, utility capacity, maintenance requirements, production flexibility and metallurgical requirements. For benchmarking, a useful rule of thumb is to separate energy savings from cost savings. In suitable billet-heating applications, induction heating may use up to 50% less energy than traditional gas furnaces because it generates heat in the billet instead of heating a large furnace chamber, surrounding air and refractory. The cost savings will vary with natural gas rates, electricity rates and demand charges, but the operating savings can also come from faster heat-up, less idle time, reduced scale loss and scrap, better temperature repeatability, and lower heat released to the shop floor. For high-volume, repeat-part lines, those factors may shorten payback and make induction worth modeling even when electricity appears more expensive on a per-unit basis. 10 The right question is not, “Should every furnace become electric?” The better question is, “Where does electric heating make operational and financial sense?” Repeat parts, smaller billets, high-volume lines, precise temperature requirements and applications with high idle losses may be good candidates for analysis. Do Not Ignore Compressed Air Compressed air is one of the most expensive utilities in a manufacturing plant, and it is often one of the least managed. In forging facilities, compressed air may support controls, cylinders, cooling, blow-off, cleaning, instrumentation and other plant functions. Because leaks are invisible and compressors are often located away from production areas, waste can go unnoticed for years.

12 FIA MAGAZINE | AUGUST 2026