| 摘要 |
The present invention can be used for monitoring quality of welds when welding elements of metallic structures made of high-strength steel. The proposed method for determining the crack resistance of hardened steel welds implies carrying out tests with delayed fracture of samples. The method is distinctive by applying a side tensile force that causes the uniform distribution of stresses along the height of the weld, without forced stress concentration, until the stress limit of the weld is achieved, and then reducing the tensile force and, accordingly, stresses in the sample at the stage of the plastic deformation of the sample. In order to form the continuous tensile force and reduce the stresses at the stage of the plastic deformation of the sample, a prestrained resilient element is used. The extent of the decrease of the deformation of the additional resilient element is used for determining current tensile stress in the sample, specifically the stress at the fracture of the sample, the state of the sample that corresponds to its plastic deformation, the specific work of deformation, and the state corresponding to the fracture of the sample. Additionally, the proposed method implies determining the intervals when microcracks in the sample are formed and the number of such microcracks. The proposed device for the realization of the method contains a number of plates made of hardened steel having the same thickness, which are arranged in a single plane and joined with the tested weld sample, and facilities that are used for determining the structure and properties of the weld. The present indention provides a possibility to increase accuracy when testing welds for determining their crack resistance.
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