Gas-shielded solid-cored welding wire welding technique for pressure-bearing welds of pressure-bearing equipment

Abstract

The invention relates to a gas-shielded solid-cored welding wire welding technique for pressure-bearing welds of pressure-bearing equipment. The technique is characterized in that the technique includes the following steps that: (1) a matched welding wire is chosen according to the material of a container to be welded; (2) carbon dioxide and argon are adopted as shielding gases, the proportion of the argon among the shielding gases is regulated to 70 v percent to 90 v percent, and the rest is carbon dioxide; (3) welding current, voltage and welding speed are determined according to the material and wall thickness of the equipment to be welded; (4) the power supply of a gas-shielded welding machine is switched on to start welding; (5) after welding is finished, post-weld heat treatment is carried out on the weld. Since the carbon dioxide and the argon are adopted as shielding gases, the impact toughness of the weld can be effectively enhanced, the welding quality is ensured, and meanwhile, because submerged-arc welding is adopted to substitute the conventional manual welding wire welding, the welding efficiency is greatly increased.

Description

technical field [0001] The invention relates to a gas-shielded welding process of a solid core welding wire for a pressure-bearing welding seam of a pressure-bearing equipment. Background technique [0002] For the welding of large pressure vessel welds with a diameter of more than 8 meters, the automatic submerged arc welding process is basically used for submerged arc welding, and manual arc welding is usually used for welds that are not suitable for submerged arc welding. Manual arc welding is not only inefficient, but also the welding quality is affected by other factors, and the quality is unstable. [0003] In order to improve welding efficiency and ensure welding quality, people try to use submerged arc automatic welding process for all welding seams of pressure vessels. Since submerged arc welding is only suitable for flat seam welding, the staff puts the container to be welded on a device that can rotate the container, so that the container to be welded lies down a...

AI Technical Summary

Problems solved by technology

However, along with the large-scale and even super-large petrochemical installations, the diameter of the container increases continuously, but the wall thickness of the container does not need to increase in the same proportion, so the phenomenon that the wall plate of the container is relatively thin appears. For automatic submerged arc welding, it is not only necessary to add a reinforcement ring inside or outside the equipment to ensure the stability of the container cylinder during rotation, but also, when the diameter of the container reaches more than eight meters, the outside of the main weld of the equipment needs to be within 10 meters. Welding at a height of more than one meter, the construction safety is poor, and at the same time, the local stress of the contact part with the roller when the container is rotating is too high, causing damage to the container material

In view of this, the welding of such welds is still dominated by low-efficiency manual arc welding, which requires a large number of excellent welders, which increases the cost of equipment manufacturing, but the welding quality cannot be guaranteed

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