Effect of Heat Treatment on the Bending Behavior of STS/Al/STS Hybrid Metal Plates

Abstract

The microstructures and bending properties of STS439/Al1050/STS304 clad plates were investigated after annealing process at various temperatures. Interfacial layer was developed at the STS439/Al1050 and Al1050/ STS304 interfaces at 550OC. The presence of Al3Fe2 at the STS/Al interface was confirmed by EDX. The initial bending hardenability and load under condition A (STS439 side in tension) was found to be greater than under condition B (STS304 side in tension). The higher hardenability and load under condition A can be explained by the greater strain hardenability of STS439 (bottom side) in tension. No interfatial cracks were observed across the interface in the as roll-bonded clad composite and annealed clad composites at 450OC. After annealing at 550OC, the load drops in the early part of load-displacement curves associated with the interface debonding was observed. As-rolled clad metal and that annealed at 450OC exhibited the relative high load.