Static and fatigue tests of bimetal Zr-steel made by explosive welding

The paper presents the test results of the microstructure, mechanical properties and fatigue cracks obtained for zirconium-steel bimetal under cyclic bending. The research was carried out for initial state bonds, i.e. immediately following explosion welding. The results of mechanical and structural investigations of the intermediate layers were presented. Using scanning electron microscopy (SEM) allowed the initial identification of the forming phases. In order to determine changes in the value of strengthening, microhardness tests of both the weld and the joined plates were performed. Specimens of rectangular cross section were fatigue tested. In the tested specimens, the ratio of heights of base and overlaid materials was h1: h2 = 2.5: 1. In the specimens, the fatigue crack growth was parallel to the applied load. The specimens exhibit the uniform crack growth at both sides of lateral surfaces. Among composite fractures in the zirconium and steel, transcrystalline cracks are dominating.