Electro-gas welding method for 42-50 mm high-strength steel plate for ship body

Abstract

The invention relates to the field of ship manufacturing, and discloses an electro-gas welding method for a 42-50mm high-strength steel plate for a ship body, which comprises the following steps of: arranging a single-sided V-shaped groove at a welding position; the back of the weld joint is welded and fixed with a steel plate; a gasket is installed on the back face of the welding groove, and the gasket is tightly attached to the steel plate through a wooden wedge; a welding guide rail and a welding trolley are installed on the front face of the welding groove in the direction parallel to the welding groove; the angle of a welding gun is adjusted, the angle between the welding gun and the surface of the workpiece to be welded is 10-15 degrees, the flow of protective gas is 35 L/min, the welding current is 450-470 A, the welding voltage is 40-44 V, the welding speed is 4 +/-1 cm/min, and the front face and the back face of a welding seam are formed at a time. On the premise that preheating is not conducted before welding, electro-gas welding of the 42-50 mm high-strength steel plate for the ship body can be met, the purpose of outdoor efficient welding construction is achieved, the welding period is shortened, the welding seam quality is improved, and the post-welding grinding time is shortened.

Description

technical field [0001] The invention belongs to the field of shipbuilding, and in particular relates to a gas-electric vertical welding method for a high-strength steel plate for a 42-50mm hull. Background technique [0002] Gas electric vertical welding is a high-efficiency welding method with large heat input. Due to the high welding efficiency, there is no need to set up scaffolding during welding, and an elevated vehicle can be used. It is especially suitable for open-air field operations. It is generally used for vertical welding with a plate thickness of less than 35mm. Butt welds (marine high-strength steel plates generally do not require preheating before welding if the thickness is less than 35mm, and preheating is required before welding if the thickness is greater than 35mm, which affects the welding efficiency of gas-electric vertical welding). [0003] The deck group of our bulk carrier adopts the side PE method, that is, the butt weld of the segmented group dec...

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Problems solved by technology

[0002] Gas electric vertical welding is a high-efficiency welding method with large heat input. Due to the high welding efficiency, there is no need to set up scaffolding during welding, and an elevated vehicle can be used. It is especially suitable for open-air field operations. It is generally used for vertical welding with a plate thickness of less than 35mm. Butt welds (high-strength steel plates for ships with a general thickness of less than 35mm do not need to be preheated before welding, and those larger than 35mm require preheating before welding, which affects the welding efficiency of gas-electric vertical welding)

[0003] The deck group of our bulk carrier adopts the side PE method, that is, the butt weld of the segmented group deck is in the form of vertical welding, and the thickness of the deck steel plate is generally 42-50mm. Manual CO2 welding is conventionally used. Preheating at 100-120°C, low welding efficiency, difficult operation, poor appearance quality of weld seam, long time for welding seam grinding after welding, very difficult preheating before welding in standing position and high-altitude operation, and the preheating efficiency is not high, requiring feet Hand assistance, etc.

Take a 208,000-ton bulk carrier as an example: one of the vertical butt welds on the deck is about 13 meters long, and two welders need about 40 hours to complete it, especially when it is windy and rainy, the construction period will be longer

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