Bright, precise, process-reliable: Listemann hardens your components in a vacuum with high-pressure gas quenching – ideal for precision parts, tools and martensitic stainless steels.
During vacuum hardening, your components undergo Heat treatment in an oxygen-poor environment. Cooling is performed by powerful blowers with high-pressure gas quenching (HPGQ) in nitrogen or argon. This prevents oxidation and scale formation, surfaces remain bright and dimensional and shape deviations can be reduced.
The process at a glance: Cleaning & set-up → Evacuation (up to the high-vacuum range) → Preheating → Austenitizing at material-specific temperature → Gas quenching (typically 1 – 6 bar) → Tempering to adjust hardness and toughness. Each step is monitored and recorded to ensure a high level of reproducibility and traceability.
Ideal for fitting and sealing surfaces as well as for subsequent coatings (e.g. PVD).
Uniform, media-free quenching reduces machining work after hardening.
No oil or salt residue, cleaning usually minimal.
Recipes, batch tracking and measurement curves ensure repeatable quality.
- Cold work steels such as 1.2379 (X153CrMoV12) for cutting and punching tools
- Hot work steels such as 1.2343 / 1.2367 for mold inserts and die casting tools
- Powder metallurgical steels (PM) for highly stressed tools and molds
For example 1.4034 / 1.4057 - combine corrosion protection with a hardenable matrix, suitable for precision components and instruments. These steels are often used in medical technology due to their increased corrosion resistance. Heat treatment ensures the best compromise between strength and corrosion resistance.
For example, 1.4542 (17-4 PH) or 1.4568 (17-7 PH) combine excellent toughness with good corrosion protection.
The achievable hardness depends on the material and microstructure. We advise you on the optimum balance of hardness, toughness and dimensional stability, recommend the required number of tempering cycles (usually 2-3) and test according to current standards (e.g. ISO 6508).
On request, we can document hardness values (HRC/HV) and – if necessary – microstructures in the micrograph.
Surface: Vacuum hardening provides bright, oxide-free surfaces; oil/salt can cause oxidation/scale.
Dimensional accuracy: The uniform gas quenching reduces the tendency to warp – less reworking.
Cleanliness: No media accumulation, low cleaning requirements.
Process stability: Excellent reproducibility thanks to control of all heat treatment parameters
Occupational safety & environment: No handling of flammable oils or molten salts.
Until max. 1500 x 1700 mm and 2000kg per batch. We check larger dimensions individually – ideally with a drawing.
This depends on the material. High HRC values are possible for common tool steels; for martensitic stainless steels, we tailor the hardness and tempering strategy specifically to toughness and corrosion requirements.
Vacuum hardening is suitable for all steels whose critical martensitic cooling rate matches the capabilities of the vacuum furnace. This means that case-hardening steels and heat-treatable steels, for example, are generally not suitable for vacuum hardening.
Through suitable component orientation, clean surfaces, uniform wall thicknesses, defined stress relief annealing and well thought-out preheating/austenitizing. We provide support with fixture and orientation recommendations.
Significant changes in wall thickness, sharp edges and notches increase the potential for cracking/distortion. An appropriate design plus suitable fixturing minimizes risks.
Hardness reports (HRC/HV), batch reports (temperature/pressure), microstructure evaluations and material certificates on request. Certificates: EN9100 / Nadcap.
Typically 3 working days from technical approval. We are also happy to offer a 24-hour service within the scope of our possibilities.
Phone: +41 52 245 18 55
Mobile: +41 77 442 46 91
t.bachmann@listemann.com
Phone: +423 375 90 12
Mobile: +423 78 05 401
t.bitschnau@listemann.com
Phone: +48 12 6534 231
Mobile: +48 501 65 22 26
j.brelinski@listemann.com
Our new check helps you to get a professional assessment of possible projects within our procedures about the feasibility in the shortest time. We inform you whether and how a realization becomes possible.
With our know-how you open up the problem-free entry into new technologies. Our materials expertise helps you to bring products with innovative material properties to market and thus strengthen your competitive position.
