Investigation of fracture mechanical behaviour of nodular cast iron and welded joints with parent-material-like weld metal
Investigation of fracture mechanical behaviour of nodular cast iron and welded joints with parent-material-like weld metal
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球墨铸铁和类母材焊缝金属焊接接头断裂力学行为的研究
DOI：
10.1520/stp16395s
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发表时间：
1995
期刊：
影响因子：
--
通讯作者：
G. Pusch
中科院分区：
文献类型：
--
作者：
W. Baer;G. Pusch
调查的重点是确定断裂力学特性和裂纹阻力曲线的J积分和CTOD概念的应用程序的部分卸载柔度技术和直流电位降技术（四点弯曲）在静态载荷下。结果表明，在考虑石墨颗粒缺口效应的情况下，基体（石墨颗粒间距）对铁素体球墨铸铁的抗裂性和断裂性能的影响是主要的。SEM原位拉伸试验表明，由于强度优于母材类焊缝金属（失配比M = 1.21）的有利屏蔽效应，直接位于熔合线平面内的裂纹没有偏离到焊缝金属中，尽管其韧性低于母材。在裂纹尖端前还出现了不对称的损伤。
The focus of the investigations was the determination of fracture mechanical characteristics and crack resistance curves of the J-Integral and CTOD concept by application of the partial unloading compliance technique and D.C. potential drop technique (four point bend) under static load. The results show a close correlation between crack initiation values as well as crack resistance curves and graphite morphology parameters determined by means of quantitative microstructural analysis where the influence of the matrix (distance of graphite particles) dominates the crack resistance and fracture performance of ferritic nodular cast iron under consideration of the notch effect of graphite particles. SEM in-situ tensile tests showed that due to a beneficial shielding effect of the strength overmatching parent-material-like weld metal (mis-match ratio M = 1.21), cracks positioned directly in the plane of the fusion line did not deviate into the weld metal in spite of its lower toughness compared to that of the parent material. They also showed an unsymmetrical formation of damage in front of the crack tip.