Nodular cast irons are an excellent alternative in manufacturing process of axels due to their characteristics and good mechanical properties. However, the necessity of joining the axels to the gears and other components, made in carbon steel, is a great challenge. Traditional fusion welding methods applied to dissimilar ferrous materials are not deeply studied. In this context, it is well known that different materials have distinct melting points which can cause difficulty in welding, besides of defects formation from solidification. Therefore, modern joining processes such as Friction Hydro Pillar Processing (FHPP) are a great alternative. In this technology, a consumable rod is rotated against to a base material, generating the heat due to the friction, promoting materials in the plastic state and then producing the weld. Hence, this work presents a preliminary study of FHPP between the FE55006 nodular cast iron and SAE 8620 steel and evaluates the rod geometry influence on microstructure and surface stresses of the welded joints. Two rod geometries were used and two welds were further produced. The results indicated that an increase in the rod contact area promoted a lower surface stress as well as a better welded joint.
Computational Thermodynamics of Materials Zi-Kui Liu and Yi Wang
