Tensile Deformation Study on Heat Affected Zone of Mod. 9Cr-1Mo Steel Weld

Tensile deformation behavior of the heat affected zone (HAZ) of Mod. 9Cr-1Mo weldment has been characterized. Different microstructural regions (coarse grain, fine grain and inter-critical) of the HAZ have been experimentally simulated using weld simulator. Flat tensile specimens, with desired microstructural region in the gage portion, were extracted from simulated bars prior and after post weld heat treatment (PWHT). The tensile tests have been carried out at ambient temperature. Parallelly, the local deformation characteristics of the HAZ have also been assessed using automated ball indentation tests to assess material specific parameters for constitutive model. Further, FEM analyses have been carried out to assess the effect of stress triaxiality on deformation behavior across the HAZ interfaces. The effect of triaxiality on the spread of plastic zone has been discussed.