Study on Local Dry Welding of 304 Stainless Steel in Nuclear Power Stations Repair

Abstract

Local dry welding is an important water welding method with special advantages for good flexibility in nuclear power stations repair where operation spaces are usually very limited, and it can be applied perfectly by simple integration of a lot of welding processes with shielding cup. An underwater welding system chamber was built, which is mainly comprised of an underwater welding test chamber, and a hydraulic driven underwater welding device. Shielding gas is inflated to the small compacted cup to drive water and protect arc and weld pool. At shallow water of 100mm,Pulsed MIG tests were carried out to investigate parameters which are related to welding process of 304 stainless steel cladding layers. Welding tests at different depth indicates that although profiles of welds produced both at pressures of 5 meters water depth and at pressures of 15 meters water depth are perfect, but cladding layer at 15 meters is more narrow and more high

Investigation on Microstructure and Properties of Duplex Stainless Steel Welds by Underwater Laser Welding with Different Shielding Gas

“…In order to reduce the cost of operation and maintenance, underwater welding is usually used to repair cracks and surface corrosion defects in nuclear power plants. Underwater welding is mainly divided into three methods: underwater dry welding, underwater wet welding and underwater local dry welding [4][5][6][7] Underwater dry welding has good welding quality, but the welding process is complex, resulting in a significant increase in cost; the underwater wet welding device is simple, but it cannot guarantee the welding quality; local dry welding combines the advantages of the first two methods, which not only ensures the welding quality, but also reduces the equipment cost. It is very suitable for the construction [8] and maintenance of underwater nuclear power plants [4].…”