一种应用于LNG储罐立焊缝焊接的新工艺

A New Welding Process for Vertical Weld Seams in LNG Storage Tanks

摘要

某LNG站线扩建项目建设2台22万m³LNG储罐，储罐内罐壁板立焊缝焊接工艺由传统的焊条电弧焊工艺（SMAW）改变为全自动化复合TIG（GTAW）焊工艺。当前经济状况下技能型焊工用工成本居高不下，随着科学技术的飞速发展；全方位自动化焊接设备越来越受预制工厂、生产企业的青睐，手工焊条电弧焊技能人员改变为自动化设备操作工；对焊接技能水平要求大大降低。自动化焊接工艺投入使用前期通过对该新工艺试件的模拟焊接、开展工艺评定的实验验证等双重试验；将该新工艺成功应用于某项目2台22万m³LNG储罐内罐壁板立焊缝的安装焊接工作中。该自动化新工艺应用不但降低项目建设过程中人工投入，减少焊材用量，节约经济成本，而且焊接完成后的焊缝达到外观成型美观、改善焊缝力学性能、焊缝表面几乎不需要打磨、提高焊后目视检查一次性验收合格率、大大减少立焊缝焊接作业的工期。该自动化焊接工艺投入应用的到业界专业人员的高度认可；为后续项目的使用起到带头引领作用。

Abstract

The expansion project of an LNG station involved the construction of two 220,000 m³ LNG storage tanks. The welding process for the vertical weld seams on the inner tank walls was replaced from the traditional submerged arc welding (SMAW) method with a fully automated composite TIG (GTAW) welding process. Under current economic conditions, the labor cost for skilled welders remains high; however, with the rapid advancement of science and technology, fully automated welding equipment has gained increasing popularity among prefabrication plants and manufacturing enterprises. Manual SMAW operators have transitioned to operating automated equipment, significantly lowering the required welding skill levels. Prior to deployment, the new automated process underwent dual testing-including simulated welding of trial specimens and process evaluation experiments-which successfully validated its effectiveness in installing and welding the vertical weld seams on the inner tank walls of the two 220,000 m³ LNG storage tanks for the project. The application of this automated process not only reduced labor input and welding material consumption during construction, thereby cutting costs, but also resulted in welds with aesthetically pleasing appearance, improved mechanical properties, minimal surface grinding requirements, higher first-pass visual inspection pass rates, and significantly shortened welding timelines for vertical seams. The automated welding process has received high recognition from industry professionals and serves as a pioneering example for future projects.

关键词

LNG储罐 / 立焊缝 / 焊接 / 自动焊 / 工艺

Key words

LNG storage tank / vertical weld seam / welding, automatic welding / process

参考文献

[1] BS EN14620-2:2006 0℃~-165℃冷冻、液化天然气用立式圆柱形平底钢制储罐的现场设计和制造 第二部分金属构件。

[2] GB/T 26978-2021 现场组装立式圆筒平底钢质液化天然气储罐的设计与建造。

[3] SH T 3561-2017液化天然气（LNG）储罐全容式钢制内罐组焊技术规范。

[4] EN ISO 15614-2:2017 金属材料焊接工艺评定和规范。

[5] 云南化工 2024年3月 第51卷第三期 大型LNG储罐９％Ｎｉ钢焊接质量控制探讨

[6] 压力容器 2024年1月 第41卷第1期大型LNG储罐三种高效自动化焊接工艺对比研究