Evaluation of different filler metals on welding Super Austenitic Sanicro 35® (UNS N08935) Grade for refineries, chemical and petrochemical industries

Paper ID: C2025-00200 ABSTRACT: Alloy 35Mo (UNS N08935) is a super-austenitic alloy with excellent corrosion resistance in high chloride applications or in acidic environments with halide contaminants. It is a cost-efficient alternative to nickel-based alloy 625 for refineries, petrochemical and chemical plants, and renewable energy applications where duplex stainless steel is no longer an option. For fabrication, the welding process is crucial, particularly when selecting filler metal. However, at times, certain filler metals may be challenging to acquire or have extended delivery times. The goal of this study is to assess the mechanical properties and corrosion resistance of Sanicro® 35 weld joints using three different filler metal alloys: ERNiCrMo-13, ERNiCrMo-4, and ERNiCrMo-10, along with Gas Tungsten Arc Welding (GTAW) as the welding method. This study is a continuation of the previous paper, C2024-20854. The welding qualification requirements were used to assess the welds according to ASME Section IX (tensile, bending, and hardness), and the microstructure of the weldments was examined. Additionally, pitting corrosion and chloride stress corrosion cracking (Cl SCC) were evaluated using ASTM G48 Method C and ASTM G123.