Stress relieving heat treatment
All steel grades are heat-treated for stress relief to create best conditions for low-deformation processing of parts. The material is heat-treated for stress relief in our furnaces (total daily capacity: 240 t). The success of this process is largely determined by the long cooling down period of 14 hours (35 °C/hour).
Three furnaces for 240 tonnes of steel
During the production of steel plates tension grows in the material from various machining processes – caused, for example, by irregular temperature. After the inspection of incoming goods at Meusburger, all steel plates are heat treated for stress relief in one of the three furnaces at approximately 580°C for 24 hours. The daily capacity of the Meusburger furnaces is 240 tonnes.
With stress-relieving heat treatment, the tension in the material is minimised without major changes to the microstructure or strength. This is a great advantage during subsequent machining. If there was still tension in the material, it would, for example, cause distortion during sawing or milling. During stress-relieving it is important to heat the plates slowly and consistently and then maintain this level for six hours. This guarantees that thick plates are also heated through to the core.
Cooling for 14 hours
The subsequent slow, regular cooling phase of 14 hours in the furnace is even more important. Here the plates are cooled by approximately 35°C per hour. If they are cooled more quickly, tension - and even the formation of cracks - could once more occur in the material.
Advantages of stress-relieved steel
- Reduced warping during machining
- Shorter machining times due to reduced oversize
- Longer lifetime of tools
- No quenching cracks in subsequent heat treatment
- Advantages in automated processing, particularly when using clamping systems