EH36钢埋弧焊接头CTOD试验中的突跃效应及评价  

Pop-in effect and its assessment in CTOD test for submerged-arc welded joint of steel EH36

作　　者：王建平[1] 霍立兴[1] 张玉凤[1] 王东坡[1] 

机构地区：[1]天津大学材料科学与工程学院,天津300072

出　　处：《焊接学报》2004年第5期80-84,共5页Transactions of The China Welding Institution

摘　　要：根据BS 74 4 8试验标准 ,在对海洋石油平台用钢EH36单、双丝埋弧焊接头的焊缝和热影响区 (HAZ)进行低温下 (- 15℃ )裂纹尖端张开位移 (CTOD)测试时 ,多个试样出现了”突跃”(F -V曲线上瞬间载荷下降、位移增加变慢 ) ,亦称”POP -IN”现象。针对这一问题 ,依据BS 74 4 8-Ⅰ中的有关评定标准 ,对存在POP -IN现象的试样进行了F-V曲线上载荷 -位移变化的测量、计算 ,并在光学显微镜 (× 10 0 0 )下观察了断裂面上脆性起裂点处的微观组织 ,从而合理取舍了焊接接头这一非均质结构中出现的POP -IN效应。When CTOD (crack tip opening displacement) tests for welded joint of offshore-oil-platform steel EH36 were performed at -15°C according to test standard BS7448, phenomenon called pop-in appeared in weld and heat affected zone of many specimens prepared by single or twin wire submerged arc welding respectively. To this problem, in order to accept or reject all of pop-in effects occurred in welded joint reasonably, variable value on F-V (F: load, V: displacement) curve was measured and calculated, and microstructure around the initiation point in fracture plane was examined under optical microscope according to correlative assessing standard in BS7448 Part I. The study is very important for calculating CTOD value properly, assessing fracture toughness of welded joint accurately and constituting a welding condition rationally and effectively.

关 键 词：EH36钢 埋弧焊接头 裂纹尖端张开位移 突跃 

分 类 号：TG405[金属学及工艺—焊接]