海洋平台大壁厚铜镍管线的焊接工艺

Welding Procedure for Piping of Copper-Nickel Alloys with High Thickness

在南海深水天然气开发项目LW3-1上部模块中，壁厚为13mm的铜镍管线首次在海洋平台上服役。大壁厚铜镍管线的焊接和小壁厚管线的焊接差别较大，没有成熟的经验可以遵循，焊接难度较大。试验采用钨极氩弧焊（GTAW）焊接工艺，焊道背面采用氩气的保护，在合适的电流、电压下最终获得了良好的焊缝接头，各项性能指标符合标准和规格书要求。对大管径大壁厚铜镍管线的焊接工艺进行了研究和开发，并对背面保护情况以及容易产生的缺陷进行分析。该工艺已在南海深水天然气LW3—1项目中得到应用。

At the project ofNHDW （LW3-1）, the copper-nickel piping with thickness of 13mm was served at the platform first time. With many differences from the welding of the thinner one, there is no experience for the welding of copper-nickel piping with high thickness. In the test, GTAW was used to join copper-nickel alloys piping with 13mm thickness, and with sufficient backing protect form Argon performed, high performance joint was attained, which was up to the requirement of both the standard and specification. Then welding procedure and weldability of this material was investigated, the back shielding and disfigurement easily to happen were analyzed. The procedure now is used in the NHDW （LW3-1） Offshore Oil Field development project.