According to the Φ1422 mm pipe production requirements of the China-Russia eastern oil and gas pipeline X80M and the 5300 mm wide and thick plate production line process equipment characteristics

the complete industrialized manufacturing technology for low temperature pipeline steel has been successfully developed by means of alloy design with extra-wide and extra-thick steel plates

as well as the refinement of microstructure and TMCP fine control at Nanjing Iron and Steel Co Ltd. In order to improve the low temperature toughness of the steel 30. 8 mm plate

the 320 mm slab is rolled by turn-spread

and the spread rolling is carried out by 3 passes

and the reduction with 80 mm is performed. After widening

the longitudinal rolling is carried out

and the reduction at per pass is more than 22 mm. The steel plate enters ultra-fast cooling for cooling. The cooling temperature is set at 740 ~ 750 °C

and the final cooling temperature is 430 ~ 450 °C. The cryogenic pipeline is produced

and its microstructure is uniform and fine acicular ferrite with high strength and good low temperature toughness.