高钢级管道环焊缝断裂行为研究现状及探讨

Research status and prospect on fracture behaviour of butt girth welds in high grade steel pipelines

近年来,高钢级管道环焊缝因焊接缺陷等原因导致的失效事故频发,对高钢级管道环焊缝断裂行为、失效机理的认识和焊缝断裂预防控制技术提出了更高的要求。环焊缝的强韧性特征是其断裂和失效研究的基础,从研究手段和研究热点两个角度总结了国内外环焊缝强韧性研究现状。研究手段主要有组织结构表征、力学性能测试、热模拟和有限元仿真等。研究热点集中在结构性能设计、缺陷安全评估和失效机理方面,其中对环焊缝不同特征区域的强韧性分布规律的精确表征和掌握应得到重点关注。此外,相对于相同材质管道等壁厚焊接环焊缝,站场内不同材质和不等壁厚管道对接焊接接头韧性分布规律和损伤机理更需要开展系统研究。

In recent years,more and more safety accidents caused by failures of girth welds in high grade steel pipelines have taken place,which proposes high demand for studies of fracture behaviour,failure mechanism and control technology.High strength and toughness of girth welds are the base for fracture or failure control.In the present paper,the development status on the high strength and toughness of butt girth welds were summarized in two respects of research methods and objects.The research methods specific to girth welds mainly contain microstructure characterization,mechanical properties investigation,weld thermal simulation and finite element analysis.Research concerns mainly contain structural properties design,defect safety assessment and failure mechanism.The precise characterisation of the high strength and toughness distribution in different characteristic zones of the girth welds has been evolved as a key concern.Compared with the girth welds in the pipelines with same material and equal wall thickness,those in the pipelines with different material and unequal wall thickness in natural gas station are more varied,therefore it is more necessary to study on the toughness distribution and failure mechanism of the girth welds served in natural gas station.