Self protection flux core welding wire of pipe line steel full position

Abstract

The self-protecting welding wire with flux core for pipeline steel has welding wire comprising BaF2, SrF2 and / or CaF2 7-12 wt%, LiF 0.8-3.0 wt%, CaO 0.2-0.8 wt%, SiO2 0.1-0.4 wt%, Al 1.2-2.0 wt%, Mg 1.2-2.0 wt%, Mn 0.6-1.2 wt%, Ni 0.6-1.2 wt%, C 0.05- 0.10 wt%, Zr 0.05-0.3 wt%, B 0.002-0.012 wt%, and Fe for the rest; and flux core accounting for 18-25 wt%. It contains water in 0.010-0.120 wt%, and has reduced current fluctuation and raised welding performance.

Description

Technical field [0001] The invention relates to a welding material for metal welding, in particular to a pipeline steel all-position self-shielding flux-cored welding wire. The flux-cored welding wire of the invention is used for all-position welding of various pipeline steels whose strength is equal to or lower than X70, and can also be used for all-position welding of various steel structures of the same strength level. Background technique [0002] Since the self-shielding flux-cored wire has the advantages of no need for an external shielding gas source, strong wind resistance, good welding quality, easy operation, low production cost, and suitable for all-position welding, it has been used in oil and gas pipelines, metallurgical blast furnaces, and high-rise steel structures in recent years. widely used in construction. General self-shielding flux cored wire is also used for welding pipeline steel. In the welding process of ordinary pipes or large-diameter thick-walle...

AI Technical Summary

Problems solved by technology

But this makes the temperature of the weld pool lower, the fluidity of molten iron is poor, the penetration depth is shallow, and the welding strength is reduced

Especially when welding large-diameter thick-walled pipes, molten iron will solidify quickly, nitrogen and hydrogen are not easy to escape, and the content of diffused hydrogen is high, and pores and slag inclusions are prone to appear, resulting in a decrease in impact energy

When the ambient temperature is low and the heating is insufficient, the defects of the weld seam are more serious, the nitrogen content in the weld seam is high, and the hardness and brittleness increase; the hydrogen content is high, the fracture is prone to white spots, the impact energy is reduced, and the low temperature impact toughness is poor