Microstructural Evolution and Mechanical Properties of CSEF/M P92 Steel Weldments Welded Using Different Filler Compositions

Abstract

In the present investigation, P92 steel weld joints were prepared using a shielded metal arc welding (SMAW) process for two different fillers, E911 and P92. A comparative study was performed on the microstructural evolution, tensile strength, microhardness, and Charpy toughness across the P92 steel weldments in the as-welded and post-weld heat-treated (PWHT) conditions. The PWHT was performed at 760��C for 2�hours. To study the effect of the different filler metals and PWHT on the mechanical properties, longitudinal and transverse tensile tests were carried out at room temperature for a constant cross-head speed of 1 mm/min. In the longitudinal direction, the tensile strength of the P92 steel welds was measured as 958���35 and 1359���38�MPa for the E911 and P92 filler, respectively. In the as-welded condition, the transverse tensile specimens were fractured from the fine-grained heat-affected zone or inter-critical heat-affected zone (FGHAZ/ICHAZ) and, after PWHT, the fracture location was shifted to over-tempered base metal from the FGHAZ/ICHAZ. After the PWHT, the tempering reaction resulted in lowering of the hardness throughout the weldment. After PWHT, the Charpy toughness of the weld fusion zone and heat-affected zone (HAZ) of the E911 filler weldments was measured as 66���5 and 142���8�J, respectively. The minimum required Charpy toughness of 47�J (EN1557: 1997) was achieved after the PWHT for both E911 and P92 filler. � 2018, The Minerals, Metals & Materials Society and ASM International.