Structural Peculiarities of Niresist Grade Cast Iron after Boriding

This work describes the testing of boride layers on Niresist Type One austenitic cast iron that are obtained after boriding at low temperatures (700°C). The study includes metallographic tests as well as X-ray structural phase analysis and electronic microscopy. According to the results of layer-by-layer X-ray structural phase analysis, FeB is determined as the main phase of the surface boride layer on Niresist Type One cast iron after a ten-hour boriding at 700°C. However, the phase that shows at a depth of 20 μm is Fe 2 B, whereas the phase that shows at a depth of 40 μm is the underlayer material phase known as γ-phase. In the near-surface part of the diffusion layer, electron microscopy detects a compound corresponding to iron boride Fe 2 B 7 not detected by X-ray structural analysis.