Reduction of distortion by using of Fixture Hardening Machines

Juretzko Harald - HEESS GmbH & Co KG (Germany)

HEESS is the global leader in development, engineering and production of hardening machines as well as their integration into the heat treatment process.

Throughout the world, well-known automotive- and gearbox-manufacturer are operating with HEESS quenching presses to achieve better quality of their workpieces by reducing distortion caused during the hardening process. This achieves substantial cost reductions by avoiding scrap, reduction of rework and shorter carbonization periods.

The presentation will show the point of view from a fixture hardening machine supplier and with which technology at the heat treatment one can influence the roundness and flatness.

The working principle of fixture hardening is to flow cooling medium around each workpiece in a controlled and  reproduceable manner

and at the same time to keep it in shape by applying external forces. This has been proven to significantly reduce distortion caused by heat treatment. By treating individual parts and automating the process, a high level of reproducibility and dimensional stability are achieved. This means that rework costs for grinding processes, for example, can be minimized or partially saved and scrap rates can be significantly reduced. The cost savings are also visible in advance. Less post-processing means a reduction in grinding material and thus also the hardening depth. This means that oven carburizing times, which often last several days for these workpieces, can be drastically shortened. These energy savings cannot be ignored not only in terms of costs, but also in terms of the environment.

In the lecture, a corresponding machine and tool concept will be presented and practical experiences will be reported including an outlook on new developments and innovations.