Abstract
SCC damage of the weldment for HT-60 steel under corrosion control was evaluated, and fracture process due to SCC was modeled by analyzing the fractography and AE signals produced in the process of SCC. In case of the PWHT specimen, fracture by SCC occurred through the three steps such as formation of pits at grain boundaries, coalescence of pits and production of micro-cracks before the maximum load and final fracture. However, fracture process by SCC of the weldment consists of four steps like formation of pits at grain boundaries and within the grain, coalescence of pits and production of micro-cracks before the maximum load, coalescence of the micro-cracks after the maximum load and final fracture. Cathodic potential like -0.8V for the parent can be recommended to lengthen the time to failure and PWHT procedure was effective in improving the resistance of SCC.
