Ductile Cast Iron 350/4 using SMAW

Abstract

Abstract: This article examines the weldability of ductile cast iron when the root weld is applied with a tungsten inert gas (TIG) welding process employing an Inconel 625 source rod, and when thefiller welds are applied with electrodes coated with 97.6% Ni. The welds were performed on ductile cast iron specimen test plates sized 300 mm × 90 mm × 10 mm with edges tapered at angles of 60◦ . The plates were subjected to two heat treatments. This article analyzes the influence on weldabilityof the various types of electrodes and the effect of preheat treatments. Finally, a microstructure analysis is made of the material next to the weld in the metal-weld interface and in the weld itself. The microstructure produced is correlated with the strength of the welds. We treat an alloy with 97.6% Ni, which prevents the formation of carbides. With a heat treatment at 900 ◦C and 97.6% Ni,there is a dissolution of all carbides, forming nodules in ferritic matrix graphite.