How the EFW Process Works, EFW steel pipe production

——In depth analysis of electric fusion welding (EFW) technology

Electric Fusion Welding (EFW) Explained: 

Discover the EFW process for high-quality welded pipes, creating strong, reliable welds for large-diameter applications in stainless steel and special alloys.

Electric Fusion Welding (EFW), also known as Electric Fusion Welding, is a key welding process in industrial pipeline manufacturing. It specifically refers to the use of an electric arc as a heat source to heat metal joints to a molten state. Typically, with the addition of filler metal (welding wire), atomic bonding is achieved to form a dense and strong weld seam. The EFW process is widely used in the production of medium to large diameter and thick walled pipelines with strict requirements, especially in the fields of stainless steel and special alloys, due to its high weld quality and excellent mechanical properties.

The core feature of EFW lies in the "fusion" process. Unlike resistance welding (ERW) that relies on the current thermal resistance effect without adding filler metal, the EFW process uses strong arc energy to completely melt the edge of the base metal and the filler wire, forming a uniform molten pool. After cooling and solidification, the formed weld seam structure almost integrates with the base metal, possessing extremely high strength and toughness. This enables EFW welded pipes to withstand higher pressures, wider temperature ranges, and stronger corrosive environments.

In specific industrial practice, EFW technology includes various advanced welding methods. Taking MTSCO's welded pipe manufacturing as an example, we adopt a composite welding technology that combines fully automated plasma arc welding (PAW) with tungsten inert gas welding (GTAW). This is a highly precise EFW process: firstly, utilizing the concentrated energy and strong penetration of PAW for efficient bottom welding, ensuring complete penetration at the root of the weld seam; Subsequently, GTAW was used for filling and cover welding, which has stable arc and good protection effect, and can form high-quality welds with smooth and defect free surfaces. This advanced EFW technology combination is one of the core guarantees for us to provide high-quality welded pipes that comply with ISO/PED/AD2000/M650 certifications to global customers