TRANSFORMATION OF BORID INCLUSIONS UNDER PRODUCING OF PIPES FOR NUCLEAR POWER

Abstract. Purpose. The problem of the influence of nonmetallic inclusions is the technological plasticity of steels is actual. The goal of the work was to study the behavior of boride inclusions under plastic deformation and their effect on the technological properties of 04H14Т3R1F steel at all stages of production of hot-rolled pipes. Methods. The microstructure of steel 04H14Т3R1F and boride inclusions were studied with the help of the Neophot-21 optical microscope. A micro-analyzer REMMA 102-02 was used to determine the composition of borides. Tensile tests were conducted to determine the mechanical properties of steel 04H14Т3R1F. Results. In steel 04H14T3R1F became the presence of borides based on chromium, iron and titanium. The patterns of morphology, size and chemical-mineralogical composition of borides in the process of plastic deformation were studied. The sizes and distribution of borides in the original tube billet, liner after the first piercing and finished hot-rolled pipes were determined. The influence of borides on the technological plasticity of steel 04H14Т3R1F was shown. Their influence on the nucleation of the destruction of steel 04H14Т3R1F at different stages of production of pipes for nuclear power engineering was substantiated. Scientific novelty. The main types of boride inclusions in high-chromium steel were identified, and the redistribution of elements in them under deformation-thermal action was analyzed. The regularities of boride transformation during plastic deformation and their influence on the properties of 04Х14Т3Р1Ф steel were considered. Practical significance. The use of the obtained results made it possible to clarify the technological regimes of deformation of steel 04Р14Т3К1А at different stages of obtaining pipes for nuclear power.