A kind of circular seam welding method of inner liner of stainless steel gas cylinder

Abstract

The invention discloses a welding method for the circular seam of the inner liner of a stainless steel gas cylinder. Firstly, the secondary necking is put into the inner tank body, and then force is applied to the front head assembly and the rear head assembly to make the first-stage necking Completely enter the inner tank cylinder and fit it with the inner tank cylinder; after the assembly is completed, clamp the inner tank cylinder and pass the mixed gas shielding gas on the welding torch, and pass high-purity argon shielding gas on the welding torch drag cover. Carry out MIG welding on the inner tank ring seam; after the welding is completed, the shielding gas on the torch dragging cover is delayed for 5 to 10 seconds, and then the equipment is turned off, and the welding is completed. The present invention adopts the form of first-level necking and second-level necking for the head assembly, so that the backing plate structure is no longer used during the assembly process of the inner tank cylinder, the assembly is easy, the operation is simple, the working strength is reduced, and the work efficiency. By adopting the technology in the invention, the pass rate of the non-destructive testing reaches over 99 percent; the physical and chemical test items fully meet the standard requirements.

Description

technical field [0001] The invention relates to a longitudinal seam welding process for an inner tank of a heat-insulating gas cylinder and an LNG vehicle bottle, in particular to a welding method for a circular 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 of the inner tank. The front head...

AI Technical Summary

Problems solved by technology

However, with this method, the processing requirements for the backing plate are relatively high. If the diameter of the backing plate is too large, it will make it difficult to assemble the cylinder and the head; if the diameter of the backing plate is small, the resulting There is a gap between the circular weld and the backing plate, which can easily lead to welding defects

Moreover, the use of backing plates produces additional workload, increases labor intensity, and reduces production efficiency

[0007] There are also some manual welding methods, but the same welding seam of this welding process needs to be welded several times to achieve, the work efficiency is low, and the pass rate of non-destructive testing is not high, and the product quality cannot be guaranteed

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