Hybrid welding process for partial through welding joints of low-temperature storage tanks

Abstract

The invention discloses a hybrid welding process for partial through welding joints of low-temperature storage tanks. The hybrid welding process comprises shielded metal arc welding and gas shielded welding, is mainly suitable for fixing the T-shaped part through welding joint of a support plate and a heavy plate and the T-shaped part through welding joint of an anti-floating device web and a hanging horse as well as the heavy plate, and is also suitable for similar joints between other parts. In the hybrid welding evaluating process, grooves are firstly formed in butt joint testing plates, the position of the groove of one butt joint testing plate is welded with a NI-based welding strip to be flat by a half of groove, cutting machining of the grooves is carried out, then a gas shielded welding strip is used for welding a testing plate joint on one sides of single V grooves, and then flaw detection, stretching, bending, macroscopic, metallographic, hardness and welding line center impact tests and the like are carried out. The hybrid welding process has the beneficial effects that the hybrid welding process guarantees that the welding line quality meets the requirement according tothe defects that the shielded metal arc welding arc penetration and fusion capacity is high so that incomplete fusion of a welding line can be effectively prevented; and a molten bath for the gas shielded welding is small, the heat affected zone is narrow, after welding, a welding piece has small deformation and high efficiency, and the welding period is shortened.

Description

technical field [0001] The invention relates to the technical field of low-temperature storage tank welding, in particular to a hybrid welding process for partially penetrated joints of low-temperature storage tanks. Background technique [0002] With the development of contemporary market demand and industrial level, the volume of cryogenic storage tanks used to transport liquefied gas is getting larger and larger, resulting in increased thickness of structural parts and diversification of structural design. Among them, the T-shaped tank designed for internal component welding Partial penetration joints are gradually used to replace fillet welds. However, if the partial penetration joints use the conventional gas shielded welding process, due to the particularity of its material, structure and welding conditions, the weld seam is extremely difficult. It is prone to non-fusion defects; if all arc welding with electrodes is used, although it can effectively prevent defects su...

AI Technical Summary

Problems solved by technology

[0002] With the development of contemporary market demand and industrial level, the volume of cryogenic storage tanks used to transport liquefied gas is getting larger and larger, resulting in increased thickness of structural parts and diversification of structural design. Among them, the T-shaped tank designed for internal component welding Partial penetration joints are gradually used to replace fillet welds. However, if the partial penetration joints use the conventional gas shielded welding process, due to the particularity of its material, structure and welding conditions, the weld seam is extremely difficult. It is prone to non-fusion defects; if all arc welding with electrodes is used, although it can effectively prevent defects such as weld non-fusion, but the construction efficiency is low, especially for long and thick welds. With the development of contemporary market demand and industrial level, liquefied gas The volume of cryogenic storage tanks used to transport liquefied gas is increasing, resulting in increased thickness of structural parts and diversification of structural design. Among them, T-shaped joints designed for welding internal components, Partial penetration joints are gradually used to replace fillet welds in more and more applications. However, due to the special materials, structures and welding conditions of the conventional gas shielded welding process of such partial penetration joints, the welds are prone to incomplete fusion. Defects: If all arc welding with electrodes is used, the weld seam is long, the filling amount is large, the welding workload on site is large, and the efficiency is low. Due to the difficulty in detecting such partially penetrated joints, if all gas shielded welding is used, problems such as lack of fusion are easy As a result, there are serious hidden dangers in product welds, which cannot ensure the quality of product welds and meet the requirements of product service life. Therefore, this invention proposes a hybrid welding process for partially penetrated joints of low-temperature storage tanks.

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