17 / 2025-03-27 23:16:19

CO2 reduction for vacuum case hardening

CO2, energy efficiency, vacuum heat treatment, low pressure carburizing, gas quenching

Reducing CO2-output is one of the top-priorities for today’s manufacturing industry. Process heat is one of the major contributors to industry’s CO2-output.

For the process of case hardening, electrically heated vacuum furnaces represent an ecological and economical alternative to gas-fired atmospheric furnaces.

The main amount of energy during the vacuum case hardening process is consumed by idle losses, followed by heating up of the load and then followed by the energy needed to quench the load. Therefore, it is key to reduce idle losses by improving the insulation of the treatment chambers. It has been demonstrated that idle losses can be reduced by 55% with improved chamber insulation.

In addition, high temperature carburizing offers the potential to reduce energy consumption during the case hardening process. When using a higher carburizing temperature, more energy is needed for heating up the load. But this is overcompensated by a significant reduction in idle losses due to the shorter treatment time. For example, when targeting a case hardening depth of 1,5mm, the energy consumption is reduced by 21% when raising carburizing temperature from 930°C to 1030°C.

The paper shows practical examples on several ways and means to reduce the energy consumption of vacuum furnaces applied for the case hardening process.