Anais do Congresso Internacional de Transporte Aquaviário, Construção Naval e Offshore
Anais do 28º Congresso Internacional de Transporte Aquaviário, Construção Naval e Offshore

This work presents an investigation of the ductile tearing properties for the girth weld of a typical C-Mn pipe internally clad with Inconel 625 CRA alloy using experimentally measured crack growth resistance curves. Here, the material of the external pipe is an API 5L Grade X65 pipeline steel with a higher yield stress of 551 MPa. In contrast, the inner clad layer is made of Inconel nickel-chromium alloy 625 (UNS N06625) with a yield stress of 495 MPa and high hardening. The higher mechanical strength and superior resistance to a wide range of corrosive environments of unusual severity for this material derived from the combination of the nickel-chromium matrix with other microalloying elements. Testing of the pipeline girth welds employed clamped SE(T) specimens with a notch at the Weld Centerline to determine the crack growth resistance curves based upon the unloading compliance (UC) method using a single specimen method. Additionally, the multi specimen technique is employed to provide extra fracture toughness data and compared both methodologies. The SE(T) specimens were extracted from a clad pipe having an external diameter of 220 mm and a thickness of 23 mm. This experimental characterization provides additional toughness data that serve to evaluate the effectiveness of current procedures in determining accurate experimentally measured R-curves for this class of material, including the effects of weld strength mismatch.