Post-treating a hardened metal formed part

A method for post-treating a formed and hardened component made of a metallic material by a device for electric resistance heating, the device having at least one first pair of contact pieces and at least one second pair of contact pieces, the method comprising:

• contacting the contact pieces of the first pair with a to be heated first partial region of the component such that the to be heated first partial region is arranged between the first pair of contact pieces in a thickness direction of the component;
• contacting the contact pieces of the second pair with a second partial region of the component such that the second partial region is arranged between the second pair of contact pieces in the thickness direction of the component;
• heating the first partial region of the component to a first temperature (T1) by conducting electric current through the component using the first pair of contact pieces, wherein the first partial region is heated to the first temperature (T1) of at most of 900° C., and
• setting the second partial region of the component to a second temperature (T2) using the second pair of contact pieces, wherein the second temperature (T2) is set independently of the first temperature (T1), so that the first partial region obtains a higher ductility than the second partial region;
• wherein the formed and hardened component is produced by:
• flexible rolling of a strip material;
• cutting a blank from the strip material, wherein the blank has a varying thickness across the length;
• and
• hot-forming and hardening the blank.