关键词: X52材质, 大口径, 钢制管道, 自动焊接, 焊接设备, 焊接工艺, 焊接性能, 硬度试验

Abstract:

For the full-automatic welding joint of X52 line steel, the welding process parameters were adjusted and optimized while fully considering the mutual influence of double torch and the influence of construction environment. Mechanical tests such as tensile test, bending test, nick break test, and hardness test were conducted to verify the reliability of the welding process, forming a welding process evaluation; At the same time, the problems encountered in on-site welding were analyzed and solved, and the key points for optimizing the welding process parameters of dual torch automatic welding were summarized,forming a full-automatic welding technology with copper backing for X52 pipeline steel. By conducting metallurgical analysis and hardness test on the weld seam, the distribution of the microstructure of the weld metal was analyzed from a microscopic perspective. The positive correlation between the hardness distribution of the X52 pipeline steel weld seam, heat affected zone, and base metal and the content of pearlite in the corresponding metallographic structure was obtained, further verifying the consistency of the metallographic structure of the weld metal and heat affected zone under the welding process conditions. The results indicated that the full-automatic welding process for copper liners could be applied to the welding of large diameter steel pipe, and the use of this process could significantly improved welding quality and efficiency.

Key words: X52 material, large diameter, steel pipe, automatic welding, welding equipment, welding process, welding performance, hardness test;