The effect of hot plastic deformation on the structure and properties of surface-modified layers after non-vacuum electron beam surfacing of a powder mixture of composition 10Cr-30B on steel 0.12 C-18 Cr-9 Ni-Ti

OBRABOTKAMETALLOV MATERIAL SCIENCE Vol. 26 No. 4 2024 for synchrotron studies were cut and removed with accumulation in diff erent currents and in some places there could be a more pronounced texture. For borides, the most developed planes are the (110), (200), (002), (211) and (202) planes. Estimating the width of the spectral line at half the height of its maximum or half-width allows only an approximate estimate of the defect structure of the strengthening phase of the modifi ed layer due to the presence of many factors aff ecting the accuracy of the calculated parameters (possible boron diff usion from the strengthening phase during hot plastic deformation and the appearance of texture). Table 3 shows the change in the FWHM of borides and the matrix of the material. The broadening of the interference lines may be related to the heterogeneity of the change in the interplane distance due to a change in the chemical composition of the phases. Ta b l e 3 Change in FWHM diff raction patterns of modifi ed layers after plastic deformation The angular position is 2θ, deg. FWHM at the degree of plastic deformation 0 % 30 % 80 % For austenite 4.94 0.068 0.070 0.076 5.71 0.073 0.079 0.091 8.08 0.075 0.077 0.092 9.48 0.077 0.080 0.089 9.90 0.076 0.084 0.081 For borides 2.81 0.069 0.069 0.077 3.98 0.07 0.068 0.088 4.82 0.07 0.065 0.079 5.06 0.07 0.076 0.085 5.59 0.07 0.062 0.083 6.28 0.088 0.101 0.084 With a plastic deformation degree of 80 %, the FWHM values are maximal for both the matrix and borides. FWHM is minimal for the specimens before deformation when calculating the matrix and at 30% when calculating the borides. It can be assumed that with a degree of deformation of 30 %, the change in the peak half-width for borides is less intense than for austenite. This can be explained by the fact that the plasticity of the matrix is higher for austenite than for borides. After plastic deformation, a decrease in the unit cell parameters is typical. Austenite is characterized by cubic syngony with the space group Fm-3m (225), while boride is characterized by tetragonal syngony with I4/mcm (140). The decrease in the parameters of the austenite unit cell can be explained by the fact that an ion with a larger radius is replaced by an ion with a smaller radius. At the same time, the volume of the boride unit cell changes, which in turn indicates an increase in the content of metal atoms in it (Table 4). Conclusions The results of the study of the eff ect of hot plastic deformation on the structure and properties of the composition of the “modifi ed layer 10Cr-30B – chromium-nickel austenitic steel 0.12 C-18 Cr-9 Ni-Ti” obtained by the non-vacuum electron beam surfacing method allow us to draw the following conclusions: 1. Specimens of the “modifi ed layer – base metal” are obtained using the technology of non-vacuum electron beam surfacing of powder compositions on the surface of steel 0.12 C-18 Cr-9 Ni-Ti followed by hot plastic deformation at a temperature of 950 °C. The thickness of the modifi ed layer is 2.5 mm after the non-vacuum electron beam surfacing, and about 0.5 mm after 80 % hot plastic deformation.

RkJQdWJsaXNoZXIy MTk0ODM1