Gas quenching is a cooling process focused on quality.
More than 80% of ECM Technologies’ European and North American clients have adopted gas quenching.
ECM Technologies devotes great efforts in R&D to optimise this technology. Gas quenching is a cleaner process and therefore easy to integrate. The gas quenching parameters can be precisely adjusted to provide a substantial improvement in quality.
INTEGRATED AND ECOLOGICAL
ECM Technologies’ vacuum furnaces are an economic and ecological alternative. With ICBP® furnaces, gas quenching takes place in a specific cell in which the loaded parts are quickly transferred from their heating cell after low pressure carburizing.
Unlike with oil quenching, it is no longer necessary to wash, recycle or treat the effluent when upon exit. Gas quenching is a cleaner and cheaper process which respects the environment. It is a uniform, predictable and reproducible process because it eliminates the calefaction phenomena generated by oil quenching.
Gas quenching produces significant quality gains which can easily lead to savings, such as a decreasing percentage of waste or a reduction in post machining operations. With gas quenching, parts are closer to their final dimensions, with a high level of reproducibility.
Companies like Delphi, which now use oil and gas quenching, increase the proportion of gas quenched parts for diesel pumps parts while keeping the oil quenching for more massive components.
Single Gas Flow
The gas quenching cell is an enclosed area under pressure, which allows a load to be cooled at different rates and at different pressures (up to 20 bar absolute).
The load is cooled from top to bottom.
It is carried out by using two water/gas heat exchangers located on each side of the load. The water and temperature flow process the cooling power of exchangers and thus the cooling rate of the load.
The nitrogen gas flow is performed by two axial turbines, located above the load, in the upper part of the cell. The turbine concept is crucial to optimize the gas velocity and the power of the engines.
The quenching speed during quenching can be modulated and adjusted by changing the turbine speed quench pressure.
Over time, improvements were made in chamber design to even cell cooling: turbine blades, grid flow distribution, supply and exchanger surfaces etc.
Reverse Gas Flow
A gas quenching cell is a mechanism under pressure, which allows a load to be cooled at different speeds and pressures (up to 20 bar absolute). This cell was designed to quench either with nitrogen or helium with remarkable cooling efficiency and uniformity.
Gas cooling is performed with two water/gas heat exchangers located on each side of the load. The water flow and temperature determine the exchanger cooling power and thus the load’s cooling rate. The gas flow is performed by two mixed-flow turbines, located on either side of the load.
The gas flow is performed by two mixed-flow turbines, located on either side of the load. The large diameter design of these turbines is crucial to optimize the gas velocity and the power of the engines.
ALTERNATING GAS FLOW
Gas direction is variable – either from top to bottom or bottom to top – thanks to an ingenious system of lateral shells moving with a set of 2 cylinders in less than 1 second.
The advantage of this alternating flow is to offer the possibility to reduce the thermal gradients between the top and bottom of the load, and therefore, improving the hardness tolerance and distortion. The programming of this alternating flow is specific to each recipe.