Abstract:

The LNG storage tank uses domestically produced 06 Ni9 DR steel plate and adopts submerged arc automatic welding. During the welding process, defects such as slag inclusion, pores and cracks appear in the weld seam. By changing the welding process parameters, grouping requirements, and welding line energy control during welding, the problems encountered in welding have been successfully solved, and the welding qualification rate has reached over 98%, and welding defects are well controlled. By prefabricated installation quota and benefit evaluation analysis, high-quality assurance of submerged arc automatic welding technique can significantly improve construction work efficiency, effectively reduce labor cost, shorten the construction period of 160 dam³ LNG storage tanks, and provide technical and economic support for the follow-up high-level construction of large-scale LNG storage tanks in petrochemical industry.

Key words: LNG storage tank, welding quality, submerged arc horizontal welding, process control, construction cost, installation quota, benefit analysis

摘要：

液化天然气(LNG)储罐使用国产化06Ni9DR钢板，采用埋弧自动焊，焊接施工过程中焊缝出现夹渣、气孔、裂纹等缺陷。通过改变焊接工艺参数、组对要求、焊接时焊接线能量控制等，解决了焊接时遇到的难题，焊接合格率达到98%以上，很好地控制了焊接缺陷。经过预制安装定额分析和效益评价分析得出，埋弧自动焊技术的高质量保证能显著提高施工焊接工效，有效降低人工成本，有利于缩短160 dam³ LNG储罐建设工期，为中国石化后续大型LNG储罐高水平建设提供技术经济支持。

关键词: LNG储罐, 焊接质量, 埋弧横焊, 过程控制, 施工成本, 安装定额, 效益分析