Development of technology for production of K52 strength class steels with low chromium content, cold and corrosion resistant in conditions of the casting and rolling complex

The results of experimental testing of production in the conditions of a casting and rolling complex (CRC) Vyksa Steel Works (VSW) of rolled products with a thickness of 8–10 mm with a reduced chromium content of strength class K52 to meet the requirements of the new guidelines of Rosneft on the corrosion resistance of metal in acidic environments. Based on the C–Mn–Si–Nb alloying system, a new chemical composition of steel with a reduced chromium content (0,40%) has been developed that provides a set of consumer properties — strength (tensile strength — 530–550 MPa, yield strength — 450–470 MPa), ductility (elongation — 28–34%), cold resistance (T50 below –80°C) and corrosion resistance against hydrogen cracking (CLR = 0%, CTR = 0%) and general corrosion in a CO2-containing medium (the rate of general corrosion is not more than 0,2 mm/year). It is shown that the variation of the chromium content in the range of 0,4–0,7% does not significantly affect the rate of general corrosion both under the influence of 5% sodium chloride solution and 5% sodium chloride solution with the addition of 0,40% sodium acetic acid solution when kept in an aggressive environment for 96 hours.

Influence of the geometry arc furnace steel taphole on production parameters of the casting and rolling complex of JSC VMZ

Currently the majority of modern electric arc furnaces (EAF) are equipped with bottom eccentric taphole system. This design allows to tap metal from EAF to ladle with the minimum amount of furnace slag, leaving a part of the liquid metal in EAF for subsequent heats (“liquid start”), if this residue is sufficient. In this case, taphole has several disadvantages: - it is not completely excluded that the oxidized furnace slag enters the ladle, especially with a low level of liquid residue in the EAF, the mass of captured slag in the ladle increases; - tapping time is unstable during taphole system campaign and depends on the wear of its constituent refractories; - periodically required to replace taphole refractories, thus it’s necessary to stop EAF. Under the conditions of the casting and rolling complex JSC “Vyksa Steel Works” work has carried out to change shape EAF’s taphole system, which made it possible to reduce the effect of these disadvantages on the efficiency of the EAF.

Prospects for production of boron microalloyed steels using casting and rolling complex

Modern approaches to the production of microalloyed boron steels are analyzed, types and methods of production, current directions for their development are described. It is shown that the production of such steels on casting and rolling complexes is promising, but associated with number of technological diffi culties. Critical elements of the technology are identifi ed and plan of necessary research is proposed.