QUALITY  

Vacuum Furnaces

Vacuum furnaces are the new generation of heat treatment furnaces. These furnaces are especially used for the heat treatment of high performance tool steels.
To enable this every heat treatment process in vacuum furnaces are controlled by a highly developed computer system.
The system allows measurement of the exact temparature of the piece within the furnace.
Therefore thermal shock rates related to the piece’s heating kinetics is minimum during heating or cooling of the furnace. Also it is more reliable to control thermal distortion of the load while every single heat treatment process is recorded by computer. Another main advantage of the new generation vacuum furnaces is operator interverence is almost none during furnace operation.
This eliminates possible human error. The furnace also allows repeated heat treatment cycles without any limits.

TAMÇELİK has got two SCHMETZ vacuum furnaces with 300 and 800 kg load capacities. These furnaces have the opportunity of subzero treatment just after the conventional cooling without changing any cabinets. This unique capability is a first in Turkiye. No other furnace can accomplish this. In SCHMETZ vacuum furnaces, which are manufactured in Germany, high alloyed (includes high amount of Cr) tool steels can cool down to -185^oC by computer controlled system just after the conventional cooling. This ensures maximum transformation rates and very well wear resistance results.

Cooling is the most important stage of heat treatment of tool steels. After the homogeneous austenization stage, pieces should be cooled down as fast as necessary and as slow as possible to the transformation temperature.
In vacuum furnaces adjustable cooling pressure and direction gas circulation speed and experience of heat treater can easily obtain the desired cooling speed. Other than the adjustable parameters, the vacuum furnace can also apply isothermal waiting for different dimensions which allows cooling in marquenching technique for these tools.
Marquenching technique is especially used for heat treatment of die casting and forging tools, hot work tool steels with very different dimensions and sizes. It provides minimum deformation, maximum martensitic transformation, very high toughness rates and also high thermal fatigue resistance.

Advantages of vacuum heat treatment

• Bright metallic surface quality,
• Homogeneous heating under protective gas atmosphere,
• Homogeneous micro structure and hardness penetration to the core,
• Under high pressure gas quenching (10 bar) adjustable 4 direction cooling option which provides more reduced deformation and distortion,
• Minimum dimensional change and high toughness values related to deformation,
• Computer contolled repeatable processes,
• Recorded datas, easily shown to customer when needed to,
• Control of the piece’s exact temperature by charge thermocouples and repeatable controlled processes.
• Cooling to -185^o C in the same cabinet provides minimum retained austenite, maximum hardness and wear resistance,
• No risk of enviromental pollution.