Аннотация
This article presents the results of heat-treated low-alloy steel microstructure research using the Deform 3D program, which allows determining the optimal technological parameters of steel hardening. The object of research is pipe steel grade 12CrMoV. To determine and evaluate the heat treatment parameters affecting the increase in mechanical properties, the results of modeling in the specified program were used. To compare the results, we used the method for determining the mechanical properties during tensile testing (GOST 1497-84). In order to determine the technological parameters of heat treatment for obtaining pipes of a high strength group, the mode of thermal cyclic hardening of steel was simulated, followed by low-temperature tempering, which allows obtaining properties at the level of: tensile strength – not less than 931 MPa, yield strength – in the range 862–1034 MPa, elongation – not less than 9.0 %. The values of the mode parameters were selected according to the recommendations: heating temperature – 860 ºС; tempering temperature – 150 ºС. The results of modeling the heat treatment process were confirmed by tensile tests, as a result of which mechanical properties were obtained: tensile strength – 1093 MPa, yield point – 937 MPa and relative elongation – 11.4 %, corresponding to the property values of the Q125 strength group.