High-heat-input double-wire submerged-arc efficient welding method

Abstract

The invention discloses a high-heat-input double-wire submerged-arc efficient welding method. The high-heat-input double-wire submerged-arc efficient welding method includes technological steps of S1,adopting X-shaped grooves; S2, adopting special high-heat-input submerged-arc sintered welding flux and baking the special high-heat-input submerged-arc sintered welding flux; S3, carrying out preheating until the temperatures reach 100-150 DEG C and the interlayer temperatures reach 100-200 DEG C; S4, welding front surfaces under the condition of backing heat input lower than 80 KJ / cm and carrying out filling and cover surface welding under the condition of heat input of 80-120 KJ / cm; S5, directly thoroughly welding reverse surfaces by the aid of high currents without gouging under the condition of heat input of 100-150 KJ / cm; S6, carrying out post-weld slow cooling. The high-heat-input double-wire submerged-arc efficient welding method has the advantages that the high-heat-input double-wire submerged-arc efficient welding method with the high heat input of 80-150 KJ / cm is high in welding efficiency and little in welding deformation, weld seams are free of defects, and welded connectors are excellent in mechanical performance; particularly, the welded connectors are good in low-temperature impact toughness, and low-temperature impact energy of the welded connectors at the temperatures of -40 DEG C is higher than 100 J.

Description

technical field [0001] The invention relates to the technical field of ships, in particular to a high-efficiency welding method for double-wire submerged arc welding with large heat input. Background technique [0002] With the development of shipping level, the trend of large-scale ships is becoming more and more obvious, and with the development of large-scale ships, the proportion of large and thick steel plates on ships is also increasing. The deck of the latest generation of 400,000-ton ore ships is 49mmEH36 thick plate , such as using ordinary welding technology for welding, it will inevitably face problems such as low efficiency and high work intensity. The heat input of this welding process is generally less than 80KJ / cm, although it can improve the welding efficiency to a certain extent, it still cannot meet the needs of efficient production. [0003] However, the application of double-wire submerged arc welding with large heat input is limited. The main reason is ...

AI Technical Summary

Problems solved by technology

[0002] With the development of shipping level, the trend of large-scale ships is becoming more and more obvious, and with the development of large-scale ships, the proportion of large and thick steel plates on ships is also increasing. The deck of the latest generation of 400,000-ton ore ships is 49mmEH36 thick plate , such as using ordinary welding technology for welding, it will inevitably face problems such as low efficiency and high work intensity. The heat input of this welding process is generally less than 80KJ / cm, although it can improve the welding efficiency to a certain extent, it still cannot meet the needs of efficient production

[0003] However, the application of double-wire submerged arc welding with large heat input is limited. The main reason is that the following problems are prone to occur during welding: the welding thermal cycle process is more complicated, and defects such as cold cracks and hot cracks are prone to occur; the welded joint has coarse grains and poor impact toughness. Poor; welding deformation of thick plates is difficult to control

Images