Abstract:In this paper, the welding experiments of polar ships used FH40 low temperature high strength steel were carried out by using three different methods: shielded metal arc welding (SMAW), flux-cored wire CO2 gas shielded welding (FCAW) and submerged arc welding (SAW). The weldability of FH40 steel with matching welding consumables in different welding position and joint type conditions were analyzed, and the welding process parameters were obtained. X-ray inspection, non-destructive testing, metallographic structure observation and mechanical properties tests were performed after welding process. The results showed that sound and defect-free joints were obtained with good weld appearance, and the destructive testing results met the requirements of the corresponding specifications. The mechanical properties, such as the tensile strength, the bending strength and the low-temperature impact toughness, met the design requirements. The welding process parameters determined by the experiments would provide guideline for the construction of new type polar ships.