A mid-western US automotive components manufacturer was facing growing pressure from OEM customers: tighter hardness tolerances, higher volumes, and stricter audit requirements. Their legacy box-type heat treatment furnace could no longer keep up — batch quality was inconsistent, energy costs were high, and the line could not match the takt time of the automated production cells.

To solve this, the customer commissioned a special custom Tube Type Heat Treatment Furnace (Custom Heat Treatment Furnace, 580kW, 1100°C) designed and built by our team, dedicated to gears, shafts and other critical steel parts.

Customer background & pain points

The plant mainly processes automotive gears, shafts and differential components. Before the upgrade, they relied on an aging box-type Heat Treatment Furnace for carburizing, normalizing and tempering. Over time, several pain points became critical:

• Inconsistent hardness and microstructure
  Temperature uniformity was difficult to control, leading to noticeable batch-to-batch variation. Some parts required rework, directly impacting delivery and cost.

• High energy consumption per part
  Inefficient insulation and non-optimized burner/heating layouts meant the furnace consumed a lot of power to maintain temperature, pushing unit energy cost up.

• Bottleneck in an otherwise automated line
  The rest of the production line was largely automated (robot loading, conveyor transfer, automatic washing), but the old furnace still required manual loading/unloading and frequent operator intervention.

• Limited process window for future materials
  The existing system struggled near the upper end of its temperature range and offered little margin for new alloys or higher-temperature trials demanded by R&D.

These issues made management look for a Tube Type Heat Treatment Furnace solution that could stabilize quality while lowering long-term operating costs.

Key requirements for the custom heat treatment furnace

During joint evaluation and design, the US customer defined several non-negotiable requirements:

• Installed power: 580kW to support high throughput while maintaining stable temperature during continuous loading.

• Maximum operating temperature: 1100°C, to cover current carburizing/normalizing cycles and future high-alloy trials.

• Full integration with existing automation – the furnace must accept parts from robots and conveyors, with repeatable positioning and smooth handover.

• Energy efficiency and safety compliance aligned with local US electrical and safety codes, supporting future third-party certification.

• Traceability – the Heat Treatment Furnace had to interface with the plant’s MES, logging temperature curves, holding times and recipes for every batch.

The 580kW custom tube type heat treatment furnace solution

Based on these requirements, we delivered a special custom Tube Type Heat Treatment Furnace configured as follows:

1. Multi-zone tube design & temperature control

   • A multi-zone tubular chamber with independently controlled heating zones to fine-tune the temperature profile along the furnace length.

   • Maximum operating temperature of 1100°C, giving process headroom for carburizing, normalizing and high-temperature tempering.

   • High-precision thermocouples combined with PID control to maintain strict temperature uniformity and reduce hardness scatter across parts.

2. Energy optimization & safety features

   • Upgraded insulation and optimized heating element layout to minimize heat loss, improving effective utilization of the 580kW installed power.

   • Reserved interfaces for protective atmosphere and exhaust treatment to support cleaner processing and emissions control.

   • Multiple safety interlocks on doors, over-temperature and power circuits to meet US safety norms and facilitate approval by local inspectors.

3. Automation and MES connectivity

   • Standardized interfaces for robots and roller conveyors at both inlet and outlet, enabling fully automatic loading and unloading of trays/fixtures.

   • PLC and HMI designed to communicate with the plant’s MES: each batch’s temperature curve, hold time and recipe data are automatically recorded.

   • Recipe management inside the Custom Heat Treatment Furnace allows quick switching between different component types without manual re-programming.

Results: quality, energy and throughput all improved

After commissioning and ramp-up, the US customer reported measurable improvements:

• More stable heat-treated quality
  Hardness values and case depths for gears and shafts became much more consistent across batches. Rework due to out-of-tolerance heat treatment dropped significantly.

• Lower unit energy and labor cost
  Despite the 580kW installed capacity, optimized insulation and control cut energy consumption per finished part compared to the old box-type furnace. At the same time, manual handling was largely removed, allowing operators to supervise rather than constantly intervene.

• Better line balance and shorter lead time
  Continuous flow through the Tube Type Heat Treatment Furnace now matches the cycle time of upstream machining and downstream washing and inspection, reducing WIP and improving overall delivery speed.

The plant has since positioned this Custom Heat Treatment Furnace as a template for future line upgrades and is considering similar configurations for new production cells dedicated to higher-value components.