Application of Magnetic Fields to Weld Overlay Cladding to Improve Its Performance in the Oil and Gas Industry

There are increasingly more aggressive hydrocarbons, as they have high contents of hydrogen sulfide/carbon dioxide, under conditions of high pressure/high temperature. For driving these aggressive hydrocarbons, one of the most cost-effective solutions is the coating and cladding on conventional carbon steel using a corrosion-resistant alloy. The overlay is one of the methods used for the application of this cladding. However, among the main problems of this method is the dilution and micro-segregation, which causes a decrease in corrosion resistance and its subsequent failure. In this work, the application of the gas-shielded metal arc welding process with the interaction of electromagnetic fields of low intensity is proposed to overcome or at least minimize these problems. API X60 was used as base material and 316L as overlay. The interaction of the magnetic field (MF) with the molten metal causes the temperature to become homogeneous, induces grain refinement, reduces the extent of the heat-affected zone, leads to a decrement in microhardness, a decrease in dilution and micro-segregation, as well as the elimination of the magnetic blow, stabilizing the arc. This coating technique can be applied to pipelines and fittings as the trim of submarine equipment used for driving aggressive hydrocarbon.