Manufacturing method of X80 pipeline steel straight welded pipe

The invention belongs to the field of manufacturing of mechanical equipment, and in particular, relates to a manufacturing method of an X80 pipeline steel straight welded pipe. The manufacturing method of the X80 pipeline steel straight welded pipe comprises the process steps of: preparation procedure, edge milling, UOE or JCOE process molding, prewelding, inner welding, outer welding, inspection procedure before diameter expansion, steel pipe diameter expansion, water pressure experiment and product inspection. The manufacturing method adopts a brand new design for a welding groove form, renewedly distributes the welding line energy of inner and outer welding beads, increases the welding line energy of the outer welding beads, and reduces the welding line energy of the inner welding beads. The reduction of the welding line energy of the inner welding beads can prominently reduce the size of grains in a critical coarse grain area of a heat affected zone to facilitate the distribution discretization of chained M-A components, and can reduce the size of the M-A components to obviously promote the toughness of the heat affected zone. In addition, although the filling quantity of the outer welding beads is increased, the welding speed can be guaranteed without reducing the production efficiency through adjusting such process parameters as welding current and voltage.