What Are The Low Temperature Impact Toughness Requirements For Line Pipe?

Pipelines must have sufficient impact toughness at low temperature to prevent brittle fracture. Charpy V-notch impact tests are normally required to achieve the specified absorbed energy value at the specified temperature. For example, GB/T 9711 requires the average value of transverse impact energy ≥ 27J (0 ℃ test temperature), and X80 steel grade has higher requirements. Impact test shall be carried out for low temperature materials used at - 20 ℃ and below, welds and heat affected zones.