Method of making a shaped object with regions of different ductility

摘要

A shaped part with different microstructures is made by continuously conveying a succession of hardenable steel blanks having first and second regions through a furnace such that the blanks reach an outlet of the furnace each with both of the respective first and second regions heated to an austenitization temperature. Then the blanks are positioned with the second regions thereof in a chamber of a holding unit and the first regions outside the chamber, and, while holding the second regions in the chamber and the first regions outside the chamber the second regions are heated and maintained at the austenitization temperature and the first regions are cooled with air to a temperature at which their microstructures become ferritic-pearlitic. Thereafter the blanks are transferred from the holding unit to a press where they are hardened and finish shaped.