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镍铁型铸铁焊条已经相当广泛地用来焊接QT60—2球墨铸铁。然而,研究工作表明,这些焊接接头的强度较低。本文首次利用密栅云纹法研究了单向拉伸焊接接头的受力状况,获得了接头区域的全场位移、应变和应力分布。从焊接接头应变和应力分布的不均匀性,分析了裂纹产生及扩展的原因,用扫描电子显微镜观察了断口形貌,发现有大量的球状物分布在断口上,这可能是导致焊接接头低应力破断的原因。这一次现有助于改进镍铁型铸铁焊条的性能,提高接头的强度。
Ferronickel cast iron electrodes have been used quite extensively for welding QT60-2 ductile iron. However, research shows that the strength of these welded joints is low. In this paper, the force condition of unidirectional tensile welded joint was studied by using the dense grille moiré method for the first time, and the total displacement, strain and stress distribution in the joint area were obtained. From the analysis of the inhomogeneity of the strain and stress distribution in the welded joint, the causes of crack initiation and propagation were analyzed. The morphology of the fracture was observed by scanning electron microscopy and a large number of spheroids were found on the fracture surface. This may result in low stress Broken reason. This time, it has helped improve the performance of nickel-iron cast iron electrodes and increase the strength of the joint.