摘要
裂纹尖端张开位移(CTOD)作为评定海洋工程用钢断裂韧性的重要指标,已广泛应用于现代工业中.根据BS7448:part4标准,采用多式样法对海底管线钢X70进行低温韧度试验,分别建立了焊缝和热影响区的CTOD-R阻力曲线,从而确定了焊缝和热影响区的CTOD启裂值.考虑到铺设之后的安全性问题,采用较小的焊缝CTOD启裂值为参考依据.以此为基础,分别采用SINTAP标准中的一级评定和三级评定对其埋藏裂纹进行安全评估(ECA)考虑铺设环境和残余应力影响,分别得出在铺设条件下的一级评定和三级评定埋藏裂纹容许尺寸.以试验数据为依托,以BS7448和SINTAP规范为理论指导,为海底管线铺设工程中的焊接缺陷验收和拒收提供了依据,为海底管线钢质量的优劣提供参考.
Crack tip opening displacement (CTOD) as a measure of an important indicator of marine engineering steel fracture toughness, has been widely used in modem industry. According to the BS7448:part4 standards, multi-model method is adopted to conduct low-temperature toughness test for subsea pipeline steel X70, establishing the CTOD-R resistance curves in welding joint and heated affected zone (HAZ), thus determining the crack initiation CTOD value. Taking into account the security issues after laying, a smaller weld crack initiation CTOD value was referenced. Based on this, SINTAP standards were adopted to conduct the embed crack safety assessment (ECA). With laying environment and residual stress taken into consideration, the permitted measurements of embed cracks were obtained. Thus a reference for welding defect acceptance in pipeline installation and a reference to assess the quality of the subsea pipeline steel were obtained.
出处
《力学季刊》
CSCD
北大核心
2014年第1期164-169,共6页
Chinese Quarterly of Mechanics