OBRABOTKAMETALLOV technology Vol. 24 No. 4 2022 a b Fig. 8. Diagrams of residual stresses in a plate made of 5CrNiMo steel at a treatment temperature: a – 950 °C; b – 1,050 °C After the CTT of 5CrNiMo steel at a temperature of 1,050 °C (Fig. 8, b), layers with a thickness of 750–900 µm are formed [15], in which the components are tensile; on the surface take near-zero values. The component σZ has a maximum of 436 MPa at a depth of 0.05 mm with a further general downward trend, although with slight increases in values at depths of 0.2 and 0.375 mm. The σX component has at first a sharp rise to 250 MPa, and then a smooth rise to 330 MPa at a depth of 0.2 mm, and then a general downward trend with a slight increase in values at a depth of 0.4 mm. The depth of the TRS in this case is more than 0.8 mm. It can be noticed that the component σX does not have the first peak value, as the component σZ does, although they both have insignificant areas of increasing values with a general downward trend at almost the same depths. After the CTT of 3Cr2W8V steel at a temperature of 950 °C (Fig. 9, a) at a depth of the diffusion layer up to 130–150 mm [15], two zones are observed on the TRS plot: tensile and compressing – so it can be said that the TRS plots in this case are self-balanced. On the surface, the TRS components have values of 100 MPa and reach a maximum of 360–470 MPa at a depth of 0.025 mm, then a dropping occurs and at a depth of 0.18–0.25 mm it turns into compressive (σX = –150 MPa at a depth of 0.3 mm).The depth of the TRS is 0.3 mm. After HBA of 3Cr2W8V steel at a temperature of 1,050 °C (Fig. 9, b) in a diffusion layer with a depth of 500–600 µm [15], the components of the TRS on the surface are compressive with values of −125...−210 MPa, but abruptly turn into tensile and reach a maximum of 565 MPa at a depth of 0.03 mm. Then there is a smooth dropping of the components to zero at a depth of 0.35–0.4 mm and a transition to the a b Fig. 9. Diagrams of residual stresses in a plate made of 3Cr2W8V steel at a processing temperature: a – 950 °C; b – 1,050 °C
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