Material & hardenability
Provide alloy grade, starting condition, heat-treatment route and the required hardness or microstructure.
Configure a vacuum gas quenching furnace around the alloy, maximum section, fixture and batch density, with gas pressure selected as part of the complete cooling system. SYNHTE matches the hot zone, vacuum package, nitrogen or argon circuit, fan and heat exchanger to the required thermal cycle and acceptance method.

The controlling section in the production load defines the cooling demand. Gas pressure, gas identity, circulation, fan power and heat-exchanger capacity are engineered as one system.
Provide alloy grade, starting condition, heat-treatment route and the required hardness or microstructure.
Define the maximum section, part envelope, fixture, batch mass, spacing and the location of critical surfaces.
Select nitrogen or argon with the pressure, circulation direction, fan and heat exchanger sized as a system.
Agree how temperature uniformity, vacuum, cooling response, properties, distortion and cycle records will be checked.
A horizontal single-chamber VTG system keeps heating and gas quenching in the same sealed vessel. Programmed ramps, holds, pressure and circulation stages create a controlled, repeatable thermal route.
Place parts and fixtures inside the defined work zone.
Remove air and control the vacuum route for the process.
Run programmed preheat, ramp and soak stages.
Introduce the quench gas to the programmed pressure.
Drive gas through the load and heat exchanger.
Capture cycle data and document the acceptance results.
Vacuum gas quenching supports clean hardening and solution-treatment routes without oil carryover. SYNHTE matches the process to the grade, geometry, maximum section, load arrangement and required properties.
| Material / workload | Typical objective | Selection concern | Evidence to define |
|---|---|---|---|
| Tool & die steels | Vacuum hardening with clean gas cooling | Maximum section, hardenability, fixture and distortion limit | Hardness traverse, distortion method and representative load thermocouples |
| High-speed & alloy steels | Programmed austenitizing and quench | Preheat stages, soak control and required cooling severity | Recipe record, hardness and microstructure as specified |
| Stainless steels | Grade-specific solution treatment or hardening route | Solution temperature, transfer-to-cooling sequence and surface requirement | Temperature record and agreed material-property checks |
| Titanium / reactive loads | Selected vacuum heat-treatment or dehydrogenation work | Gas compatibility, contamination control and hot-zone selection | Process-specific chemistry, surface and thermal acceptance plan |
Send the alloy, maximum section, fixture and target properties for a complete process recommendation.

Horizontal vessel, insulated hot zone, heating elements, load supports and door assembly.
Backing and high-vacuum stages configured around cleanliness, base pressure and pump-down needs.
Gas storage and admission, pressure control, circulation path, high-speed fan and heat exchanger.
Programmed recipes, temperature measurement, interlocks, alarms and cycle data recording.
Fixtures, transfer equipment, cooling water, gas supply, electrical service and installation envelope.
Hot-zone material defines contamination control, operating practice, maintenance and lifecycle cost. SYNHTE selects the hot zone around the alloy family, process temperature and surface requirements.

Efficient radiant heating for demanding high-temperature cycles, with insulation, shielding and atmosphere configured around the workload.

A clean metallic hot-zone system for contamination-sensitive workloads, engineered with matched shielding, heating power and maintenance access.
Cooling performance comes from the complete quench loop: gas properties, pressure, fan operating point, heat exchanger, flow direction, fixture design and load density.
Nitrogen provides an efficient, widely available production route for compatible steel workloads.
Argon provides an inert quench route for nitrogen-sensitive materials, with fan and heat-exchanger capacity sized for its gas properties.
For a deeper comparison, read Nitrogen vs. Argon for Vacuum Gas Quenching.
SYNHTE matches nitrogen or argon and 6 or 10 bar cooling to the alloy, section and load arrangement.
The VTG family covers work zones from 300 × 300 × 450 mm to 1000 × 1000 × 1500 mm, with matched heating power, load capacity and high-pressure gas-quench systems.
| Model | Work zone (W × H × L) | Load capacity | Heating power | Gas pressure |
|---|---|---|---|---|
| VTG-335 | 300 × 300 × 450 mm | 100 kg | 80 kW | 6 / 10 bar |
| VTG-446 | 400 × 400 × 600 mm | 200 kg | 100 kW | 6 / 10 bar |
| VTG-557 | 500 × 500 × 700 mm | 300 kg | 120 kW | 6 / 10 bar |
| VTG-669 | 600 × 600 × 900 mm | 500 kg | 150 kW | 6 / 10 bar |
| VTG-8812 | 800 × 800 × 1200 mm | 800 kg | 240 kW | 10 bar |
| VTG-1115 | 1000 × 1000 × 1500 mm | 1500 kg | 550 kW | 10 bar |
Custom work zones, pumping packages, loading systems, controls and automation are available for process-specific production lines.
Load density, cooling demand, utilities and acceptance requirements are incorporated into the furnace configuration.
FAT and SAT connect machine performance with the part result through defined loads, calibrated instruments, measurement locations and acceptance criteria.
Qualified work zone, survey condition, sensor layout, setpoint and reporting format.
Ultimate pressure, pressure-rise or leak test method, pump-down conditions and cleanliness.
Representative load, thermocouple locations, gas, pressure, fan program and cooling endpoint.
Hardness, microstructure, surface condition or other part criteria named in the process specification.
Fixture, datum, inspection method and agreed comparison of distortion-sensitive features.
Recipe access, alarms, trends, batch records, traceability and required data export.
Real VTG installations combine the chamber, pumping package, gas-quench circuit, controls and maintenance access in one engineered system.


The pressure level is matched to alloy hardenability, maximum section, fixture, load density and required cooling response. The fan, heat exchanger and flow path are sized with the selected pressure.
Gas quenching is well suited to materials and sections whose hardenability supports the required properties, delivering clean processing without oil carryover. Vacuum oil quenching remains available for workloads requiring greater quench severity. Compare a vacuum oil quenching furnace.
Nitrogen provides an efficient production route for compatible steels. Argon provides an inert route for nitrogen-sensitive materials. SYNHTE sizes the fan, pressure and heat exchanger for the selected gas and workload.
SYNHTE matches the hot zone to process temperature, alloy sensitivity, contamination criteria, operating practice and maintenance requirements.
Send the alloy, drawing, maximum section, fixture, batch mass, part spacing, target properties, distortion limit, preferred gas, cycle time and annual or daily production requirement.
This page is dedicated to high-pressure vacuum gas quenching. For the broader equipment decision path, return to the Vacuum Heat Treatment Furnace hub.
Download the current reference document or compare all available SYNHTE technical resources.