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. 10. The surface of sample strips as a result of elec- trochemical etching (anodic dissolution) of samples from steel 3Kh2V8F after boriding at: а – 950 °С; б – 1050 °С Fig. 11. Diagram of residual stresses in the sample after boriding at 950 °C the local RS increase was observed (Fig. 12). This increase corresponds to the lowest tungsten content of 1.8 % (a line spectrum 4, Table 4). The performed study is in good agreement with the current data on die steel (0.3 % C, 2 % Cr, 8 % W, 0.2 % V) boriding in terms of layer thickness, elemental and phase composition, as well as with mi- crohardness values [19]. At the same time, this work is a state-of-the-art for modern RS research, includ- ing correlations with the structure and phase composition of the layers. And it should be noted that the upper-temperature limit for the investigated die steel boriding was 50 °C higher than it had been done before [19].