Fast submerged-arc welding method for X90 pipeline steel manufacturing

The invention discloses a preheating-free fast welding method for X90 high-strength pipeline steel. According to the welding characteristics of circumferential weld joints in high-strength pipeline steel manufacturing, Ar+CO2 mixed gas shielded welding is conducted on welding joints in the pipeline steel by adopting 800MPa high-strength high-toughness solid welding wires, and double-wire fast submerged-arc automatic welding is conducted on welding joints outside the pipeline steel by matching 800MPa high-strength high-toughness welding wires with CaO-CaF2-Al2O3 series alkali sintered flux. For achieving double-wire fast submerged-arc welding of the X90 pipeline steel, the high-strength and high-toughness welding wires are adopted and are matched with the alkali sintered flux. The welding speed and the welding current are strictly matched with the critical range of the arc voltage. By means of the method, X90 pipeline steel can be welded fast under the condition of no preheating, the whole welding connector has high ductility and toughness reserve, welding cracks cannot be generated, and high welding production efficiency can be achieved. The fast submerged-arc welding method for X90 pipeline steel manufacturing has the advantages of being low in production cost, easy and convenient to operate and strong in applicability and has good application prospect.