Welding structure for inner container longitudinal seam of stainless steel gas cylinder and welding method

Abstract

The invention discloses a welding structure for an inner container longitudinal seam of a stainless steel gas cylinder and a welding method. The welding structure comprises a strip-shaped auxiliary board, wherein a main gas guide hole and a gas guide groove are formed in the strip-shaped auxiliary boar in the length direction; the main gas guide hole and the gas guide groove are arranged in parallel; a plurality of gas guide small holes are formed between the main gas guide hole and the gas guide groove; the two ends of the gas guide small holes are respectively communicated with the main gas guide hole and the gas guide groove; and the cross section of the gas guide groove and the cross section of the longitudinal seam to be welded are positioned in the same plane. The welding method comprises the following steps: rolling round; carrying out butt welding and spot welding; carrying out spot welding on run-on plates and run-off plates; clamping; and welding. According to the invention, an MIG automatic welding process is adopted, so that the primary input-cost of welding equipment is low; in a later using process, the input using and maintenance costs are relatively low and the working efficiency is improved greatly. By adopting the process in the invention, the qualification rate of nondestructive testing reaches 99.4% or above in an actual longitudinal seam welding process of an insulated gas cylinder and a cylinder for an LNG vehicle; and physical and chemical test projects completely meet standard requirements.

Description

technical field [0001] The invention relates to a welding process for the longitudinal seam of an inner tank of a heat-insulating gas cylinder and an LNG vehicle bottle, in particular to a welding structure and a welding method for a longitudinal seam of an inner tank of a stainless steel gas cylinder. Background technique [0002] Welded insulated gas cylinders and LNG vehicle cylinders (also called liquefied natural gas cylinders for vehicles) are mainly composed of an inner tank and an outer shell, with a vacuum interlayer between the inner tank and the outer shell. In order to improve the insulation effect of the gas cylinder, the vacuum interlayer requires vacuuming. The inner tank of the gas cylinder is used to store low-temperature medium and withstand the internal pressure generated by the vaporization of the low-temperature medium; it is composed of three parts: the front head assembly of the inner tank, the cylinder body of the inner tank and the rear head assembly...

AI Technical Summary

Problems solved by technology

Using this welding process, because the plasma arc welding equipment is relatively expensive, the one-time investment is relatively large

Moreover, there are many welding parameters of this type of equipment, which requires high technical level of welding operators; the welding torch and control circuit are also relatively complicated, the service life of the nozzle is very low, and the later investment and maintenance costs are high; during the welding process, it is easy to produce Disadvantages of double arc, and the observation of the arc action area is prone to welding defects

[0006] There are also some manual welding methods, but this welding process needs to be welded several times for the same weld seam, and for the plate thickness ≥ 4mm, it needs to be grooved to complete, the work efficiency is low, and the pass rate of non-destructive testing is not high.

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