The structure, phase composition, and residual stresses of diffusion boride layers formed by thermal-chemical treatment on the die steel surface

OBRABOTKAMETALLOV MATERIAL SCIENCE Vol. 23 No. 2 2021 Fig. 8. XRD-pattern of the samples after boriding Fig. 9. SEM image of the boride layer: а – 950 °С, 2 h; b – 1050 °С, 2 h a b from the surface. After boriding at 1050 °C (Fig. 12), tensile RS appeared on the surface with a maximum value of 40 MPa at a distance from the surface of 45 ... 50 μm, and then turned into compressing RS with a minimum value of –124 MPa in the base metal. The active part of the RS epure was rated 0.6 mm from the surface. The stress state study of the boride layers is only a small part of the reducing brittleness problem related to the FeB/Fe 2 B borides thermal expansion anisotropy and its opposite RS sign. Today, this