Submerged arc automatic welding method of high-strength medium-carbon quenched and tempered steel for leg racks of offshore platforms

Abstract

The invention relates to a submerged arc automatic welding method for high-strength medium carbon quenched and tempered steel for pile legs and racks of offshore platforms. Weld according to the following steps: Step 1: Selection of racks; Step 2: Selection of welding materials; Step 3: Selection of rack splints to assemble tooling; Step 4: Assembling and positioning; Step 5: Preheating before welding; Step 6: Welding; Step 7 : Post-processing. The advantages of the present invention are: the present invention adopts high-strength medium carbon quenched and tempered steel ZH70Q, which has high strength and high toughness, and has small deformation during quenching. It is basically not affected by personnel, and the equipment is automatically welded according to the set parameters. It only needs to train personnel on equipment operation and basic welding knowledge to meet the advantages of equipment operation requirements, and to ensure uniform quenching and stable quality.

Description

technical field [0001] The invention relates to the field of welding technology. In particular, it relates to a submerged-arc automatic welding method for high-strength medium-carbon quenched and tempered steel used for pile leg racks of offshore platforms. Background technique [0002] The rack of the jack-up offshore platform leg is made of high-strength low-carbon quenched and tempered steel. After the rack is welded, the rack is severely worn and the tooth surface is squeezed and deformed during use. After the leg rack has a problem, it is difficult to repair due to the poor working environment on site, or the repaired part will be squeezed, deformed, shed, and worn again after repair; if the whole rack is used to replace it, the cost will be high, and the replacement technology and construction will be difficult. After the replacement part is connected with the original part, there are uncertain factors such as the difficulty of aligning the old and new butt joint defo...

AI Technical Summary

Problems solved by technology

After the leg rack has a problem, it is difficult to repair due to the poor working environment on site or the repaired part is squeezed, deformed, shed, and worn again after repair; if the whole rack is used to replace it, the cost is high, and the replacement technology and construction are difficult. After the replacement part is connected with the original part, there are uncertain factors such as new and old butt joint deformation, difficulty in alignment, large size error, pitch change, and welding difficulty

[0003] In order to fundamentally avoid the above problems, high-strength medium-carbon quenched and tempered steel materials are used for rack manufacturing, and surface quenching is performed on the tooth surface. Nowadays, manual arc welding is mostly used for welding high-strength medium-carbon quenched and tempered steel racks. Low welding efficiency, welding personnel skills and construction status have an unstable impact on welding quality, long welder training period, high technical requirements, etc.

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