Vacuum Hardening in Önerler
There are a total of 4 furnaces for vacuum hardening in our company.
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We offer flexible charging capacity with vacuum furnaces whose charging capacities vary between 250-600-1300 kg.
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IPSEN brand, 3 gas-cooled vacuum furnaces of German origin with charging capacities of 600 kg and 1300 kg
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10-5 mbar high vacuuming capacity
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With the Vacu-Prof program in the furnaces, high repeatability and traceability are ensured due to control of all critical parameters.
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Possibility to use nitrogen and argon cooling gas
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Vacuum hardening possibility for low alloy steel with 250 kg-capacity oil-cooled vacuum furnace
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Aside from vacuum hardening with our vacuum hardening furnaces in our company;
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Bright Annealing
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Brazing (brazing under vacuum)
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Demagnetization annealing
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Solution treating and aging solution hardenable stainless steels
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Softening and stress relief annealing processes are also applied to copper alloys such as brass and bronze
What's Vacuum Hardening Process ?
Vacuum hardening is a commonly used method for hardening tools, molds and martensitic stainless steels. The process has the same principle as tempering, and the main differences are the equipment, the atmospheric environment and the cooling environment. The steel to be subjected to the vacuum hardening process is first taken into the vacuum environment in a vacuum furnace. Thus, impurities diffusing from the atmosphere to the material surface during heating are prevented. After the vacuuming process, the furnace temperature is raised to the process temperature (850-1250) and austenitic transformation occurs at these temperatures. After the austenite transformation takes place, the martensitic transformation in the steel (tempering) is completed by proceeding to the cooling phase. Nitrogen, hydrogen, argon or oil may be used as the cooling medium under high pressure. The steel gone through martensitic transformation is subjected to deep cooling to remove residual austenite and then tempering if necessary, and if not necessary, it is directly tempered to obtain the required hardness and stress. This process is also preferably carried out in a furnace with a vacuum environment.
After the tempering process, the material is ready for the next stage in production, as having the required hardness and microstructure.
Benefits of The Process
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Low dimensional change
- Homogeneous hardness
- Excellent surface cleaning
- High Wear Resistance
- High Strength
- High Fatigue Resistance
- High Hardness
- High Toughness
- High Impact Resistance
- High Stability
The most basic difference between vacuum hardening and other hardening processes is that the process is carried out in a vacuum environment. For this reason, the heating and cooling steps in the process occur quite homogeneously, and the vacuum environment ensures that the material surface remains very clean at the end of the process.
Suitable Steels For The Process
In the vacuum hardening process, the cooling rate is lower than other processes since nitrogen gas is generally used as the cooling medium. Therefore, the steel to which the process is to be applied should be high alloy and highly hardenable. Cold work tool steel, hot work tool steel, plastic mold steel, high speed steel and martensitic stainless steels are frequently used in vacuum hardening.
In the following table, the steels used intensively in the market and vacuum hardened, and the maximum hardness values which they can gain after the process are given in Rockwell.
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Potential Problems After The Process
Potential Problems After The Process
Although they occur less frequently than they do in other processes, the most troublesome problem in the vacuum hardening process is the dimension changes in the materials, namely waste.​
Due to the nature of heat treatment, sudden temperature changes cause stresses in the steel resulting in dimension changes. The main reason for dimension changes that are more than expected and that would be described as a mistake can be examined in 3 main groups. Firstly, possible mistakes in the heat treatment process; secondly, mold design mistakes (thick-thin section transitions seen intensively); and lastly, residual stresses in the material during the machining phase. Cracks can also occur as a result of dimension change mentioned above.
The manufacturer should correctly identify the cleaning criteria on the part surface prior to the process. If a precise clean surface is expected, the products sent by our firm include cutting fluid, boron oil etc.; surface residues should be at minimum levels or surface cleaning service should be requested from our company before the process.Otherwise, residue, oil and dirt layers may be found on the surface of the piece after the process.
Heat Treatment
BOSB Turuncu Cad. No: 12, 16120
Nilüfer/Bursa, TURKEY
+90 (0224) 242 43 10
+90 (0224) 242 43 11 (fax)
Steel Supply
BeÅŸevler Sanayi Sitesi 26.Blok No: 6-15
Nilüfer/Bursa, TURKEY
+90 (0224) 441 97 13
+90 (0224) 441 46 15 (fax)