Effect of Thermal Shock on Rust Layer on Structural Steel

In the present investigation,the rust layer was formed on structural steel after cyclic wet/dry test.The fracture toughness of the rust layer and the interfacial fracture toughness of the interface between the rust layer and the steel were measured by means of indentation test.Quench tests were performed to determine the thermal shock resistance of the rust layer and the interface.Both the interfacial fracture toughness and the thermal shock resistance of the interface were better than those of the rust layer.Indentation cracks tended to initiate and propagate in the rust layer rather than along the interface.The temperature change could cause an original crack propagating rather than a new crack nucleating in the rust layer.