X65钢悬链立管焊缝背部几何尺寸对疲劳性能的影响  

Influence of Backside Weld Geometry on Fatigue Properties of X65 Steel Catenary Riser

作　　者：王志江 刘旺[1,2] 邓彩艳 王东坡 陈振东[1,2] Wang Zhijiang;Liu Wang;Deng Caiyan;Wang Dongpo;Chen Zhendong(Tianjin Key Laboratory of Advanced Joining Technology,Tianjin 300350,China;School of Materials Science and Engineering,Tianjin University,Tianjin 300350,China)

机构地区：[1]天津市现代连接技术重点实验室,天津300350 [2]天津大学材料科学与工程学院,天津300350

出　　处：《天津大学学报（自然科学与工程技术版）》2023年第9期911-916,共6页Journal of Tianjin University：Science and Technology

基　　金：国家自然科学基金资助项目(51505326)。

摘　　要：针对钢悬链立管单面焊双面成形过程,背部焊缝几何尺寸过大会极大降低立管疲劳寿命的问题,采用热输入小、电弧穿透力小的表面张力过渡焊接方法,研究小钝边(0~1 mm)、无间隙V型坡口全位置根焊缝背部成形工艺.对不同焊缝背部几何尺寸试样在120 MPa、150 MPa、165 MPa、175 MPa 4个应力范围下进行疲劳试验,研究不同焊缝背部几何尺寸、焊接位置对海洋立管疲劳寿命的影响.疲劳试验结果表明,该焊接工艺下管道具有良好的疲劳性能,试验数据均在DNV-RP-C203—2012疲劳设计曲线F3之上.将焊缝背面余高hb和焊缝背面宽度Wb控制在合理的范围内可极大提高海洋立管疲劳寿命.随着hb/Wb或hb的增加,焊缝应力集中系数增加,疲劳性能直线下降.不同焊接位置的疲劳寿命也有所不同.受重力影响,平焊位置焊缝背部几何尺寸较大,疲劳性能相对较差,立焊和仰焊位置焊缝背部几何尺寸较小,疲劳性能更好.In the process of one-side welding with back formation for a steel catenary riser(SCR),the fatigue life of SCR will be greatly reduced due to the large size of the backside weld geometry.To address this issue,the allposition root-pass backside weld sharpening process was studied using the surface tension transfer(STT)welding technology,which has a low heat input and minor weld penetration.A V-groove was designed with a root face height of 1 mm and no gap.To study the effects of backside weld geometry and welding positions on the fatigue life of girth welds for SCR,fatigue tests were performed on samples with different backside weld geometries at 120MPa,150MPa,165 MPa,and 175MPa.The test results showed that the pipe had good resistance to fatigue under the welding process used in this work.All test results are above the fatigue design curve F3 of DNV-RP-C203—2012.The fatigue life of SCR can be significantly improved by controlling the backside weld height hb and weld width Wb within a reasonable range.The stress concentration factor of the backside weld increases as hb/Wb or hb increases,and the fatigue performance decreases linearly.Also,the fatigue life of different welding positions varies.Under the influence of gravity,the backside weld geometry in the flat position is greater,and the fatigue performance is relatively poor,whereas in the vertical and overhead positions,the backside weld geometry is smaller,and the fatigue performance is better.

关 键 词：应力集中系数 疲劳性能 焊缝背部几何尺寸 全位置根焊 表面张力过渡 

分 类 号：TG405[金属学及工艺—焊接]