A targeted, localized heat treatment exposes the blank to a locally varying time/temperature curve. Soft regions can thus be produced beside the hard martensitic areas obtained by conventional press hardening.
Furthermore, Schwartz presents their three-zone dew point control system for roller-hearth furnaces. The technology provides dew point management in three separate, individually controlled zones via the supply of very dry air. This development started out from the observation that in aluminium-silicon (AlSi) coated parts cracks may occur after press hardening due to hydrogen embrittlement. Accordingly, even loads below the material's elastic limit may result in cracking. This phenomenon is likely to be caused by sub-dewpoint heat treatment conditions.
For the heat treatment of aluminium alloys – e.g., annealing, solution annealing and homogenizing – Schwartz developed convection and high convection equipment including a variety of systems for rapid cooling after the heat treatment cycle.
(Source: Schwartz GmbH)