Patent ID: 8211251
Filing Date: 2012-07-03
Classification: C21D,C22C,C22F

Abstract:
1. A method of accomplishing precipitation hardening of a selected portion of a formed aluminum automotive panel, the method comprising: performing i) a simulation of a bake cycle of a structure including the formed aluminum automotive panel, or ii) a test bake cycle of a structure including the formed aluminum automotive panel; identifying, from the simulation or the test bake cycle, a stress contour area which is a susceptible area of the aluminum automotive panel that experiences thermal stress as a result of thermal expansion behavior, the thermal stress above a threshold value during an actual bake cycle, thereby identifying the selected portion which is smaller than the entire formed aluminum automotive panel; and prior to the actual bake cycle, locally heating the selected portion up to a predetermined temperature for a predetermined time sufficient to increase a local yield strength of the selected portion such that the increased local yield strength ranges from 150 MPa to 300 MPa.