Residual stress analysis using CPD method in ASTM A131 AH36 steel multipass welding by SMAW and FCAW processes

Abstract:

The residual stress (RS) in welded joints of ASTM A131 AH36 were analyzed by the method DPC (coordinated points displacement). The arc welding was performed using by Shielded Metal Arc Welding (SMAW) and Flux Cored Arc Welding (FCAW) processes. The test plates with dimensions of 200 mm x 65 mm and thickness of 31,75 mm were welded according to AWS D1.1 [1] and Petrobras N-133 [2] standards (manufacture and qualification), respectively. After welding, equidistant holes with diameters of 2.00 mm and depth of 2.00 mm were drilled along the heat affected zone. After drilling, the holes were referenced on a coordinate measuring table. Then, the welded test plates were subjected to Post Weld Heat Treatment (PWHT) and then the displacements of the holes caused by the treatment were measured, making possible the calculation of residual stresses. The results obtained showed a good correlation of the DPC with other methods of measurement for TR.

Key-words:
Coordinate Point Difference; DPC Method; Residual Stresses