High-temperature failure resistance of a chromium hard-faced metal

Abstract

1. When a microalloying combination in chromium hard-faced metal consisting of ≤0.02% Al; 0.013% Y; and ≤0.05% Zr is used, the non-metallic inclusion particle size decreases and their volume fraction increases. The decrease in the size of the NI leads to a decrease in the mean grain size. 2. With the decrease in the size of the NI, there is a decrease in the plastic deformation zone around the inclusions and a corresponding decrease in the tendency of the hard-faced metal to form cracks. 3. The sulfides which form a film along the grain boundaries in chromium hard-faced metal act as initiation sites for the formation of the first microcracks in the presence of thermal cycling under a tensile load. After modification and microalloying of the hard-faced metal, ring-like microspaces form around the globular sulfides and oxides at the grain boundaries, which do not develop into microcracks. 4. Under thermal cycling conditions, the NI become smaller in size, globular, and dispersed. These factors act to decrease the negative effect of NI as sources for the initiation of microcracks in chromium hard-faced metals.