SJ101 is a fluoride-alkaline sintered flux with an alkalinity of 1.8 and a particle size of 10-60 mesh. It is suitable for both submerged arc welding and flux-cored welding. It exhibits excellent moisture resistance and high low-temperature impact toughness. The particles have good strength, the arc burns stably, and slag removal is easy. When used with appropriate welding wires such as SU26 and SU34, it can be used to weld various low-alloy structural steels, and is suitable for multi-layer welding, double-sided single-pass welding, multi-wire welding, and narrow-gap submerged arc welding.