Peculiarities of structure formation of copper-doped post-eutectoid steels

The structural state of pre-eutectoid steels alloyed with copper in the range of up to 28% was studied. It was established that the alloying of steel with a carbon content of 1.3% with copper in the amount of 8, 12 and 28% leads to the formation of the primary and secondary copper -phase The main metallic component of the structure of the studied copper-alloyed steels is represented by thin-plate copper pearlite with inclusions on the boundaries of the primary austenite grains of secondary cementite and secondary inclusions of the copper -phase. The results of the X-ray spectral microanalysis showed that the primary copperite of the -phase consists of 92.5% of copper and 7.1% of iron. The transition zone between the primary copper precipitate and the matrix, the distribution of chemical elements in it, was studied. The total size of the interphase zone is 0.4 μm. It was established that alloying of steels with 8-28% copper contributes to the formation of a highly dispersed structure of copper thin-plate pearlite, as well as the formation of areas with deformed microvolumes near the primary copper e-phase, which constitute a significant barrier to the movement of dislocations. Thus, a state with increased resistance to dynamic loads has been formed at the micro level. The obtained results open up the possibility of using post-eutectoid steels alloyed with copper in the corresponding highly loaded products Keywords: structure, post-eutectoid steel, alloying, thin-plate pearlite, e-phase, iron, spectrum.