Production method of rare-earth-containing B-grade economical ductile fracture expansion-resistant pipeline pipe

The invention discloses a production method of a rare-earth-containing B-grade economical ductile fracture expansion-resistant pipeline pipe, which comprises the following steps: pretreating molten iron, smelting in a top-bottom combined blown converter, refining in an LF furnace, continuously casting a round billet, heating a pipe billet, rolling the pipe billet, cooling by a cooling bed, cutting to length, carrying out hydrostatic test and carrying out nondestructive inspection. The pipe blank comprises, by mass, 0.09%-0.12% of C, 0.17%-0.37% of Si, 1.10%-1.30% of Mn, 0.01%-0.05% of Al, smaller than or equal to 0.018% of P, smaller than or equal to 0.005% of S, 0.006%-0.010% of RE and the balance Fe and trace impurities, and the total mass fraction is 100%. The invention aims to provide the production method of the rare-earth-containing B-grade economical ductile fracture expansion-resistant pipeline pipe, and the pipeline pipe has high low-temperature impact toughness and crack arrest toughness and can mee