OptProKomp

Situation:

In almost all industrial areas, economic objectives such as increasing productivity while simultaneously increasing energy and resource efficiency, combined with lightweight construction or component miniaturization, lead to constantly increasing performance densities and thus to ever higher static and dynamic component loads.
In addition to a design of the components suitable for bearing the loads to which they are subjected, the material steel, which is optimally suited for such stresses, is becoming increasingly important.
The conventional production chain of the spring roller bearings considered here consists of the following:
- Hot forming and subsequent cold forming (supplier),
- Winding of the spring bushings and spring rollers (cold forming),
- Hardening,
- Tempering and
- Finishing – grinding
The 3 times heating leads to:
- high energy consumption,
- Material loss due to scale / decarburization (grinding work),
- High production effort due to reworking (0.5 mm each inside and outside).
The cost of:
- the quenching and tempering and reworking amount to approx. 40 % and
- the material is approx. 18 %.

→ There is enormous potential for optimization!

Solution:

Shortening the production chain by:
- quenching and tempering and
- all subsequent process steps (reworking, etc.).
The alternative heat treatment options are:
- patenting (isothermal transformation before forming) and if necessary
- the support by the AFP concept (particle hardening after forming).
The process chain to be investigated and optimized makes it possible to generate a material with property gradients. The winding of the bearings generates a gradient in the forming process and thus also:
- Gradient in strength → outside hard,
- Gradient in toughness → inside tough.

→ No subsequent heat treatment is required any more!

Operational benefit:

The project partner Steeltec GmbH expands its product range by patented bright steels with optimized strength and toughness properties adapted to the further production process.
The project partner Eich Rollenlager GmbH shortens its process chain for the manufacture of spring roller bearings by quenching and tempering and all subsequent process steps (reworking by grinding etc.).

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