This article considers modern methods of steel production and their impact on the quality of wire rod made from grade 80 steel and applied for hardware products manufacturing. From research data on the chemical composition of wire rod produced by the oxygen-converter method and in an arc steelmakingfurnace, it can be noted that, in general, the chemical composition of the wire rod meets the requirements, while the steel produced in the converter contains less phosphorus, sulfur and non-ferrous metal impurities and nitrogen. This fact should have a beneficial effect on the ductility of the wire during further cold drawing. The analysis of the quality indicators of the finished wire rod produced from billets obtained according to various technological schemes showed that the integral quality indicator is at the same level when using optimal modes of out-of-furnace processing and continuous casting of steel.

Low-temperature coiling in the Stelmor line (∼850°C) is best for chemical scale removal. In that case, thin, dense scale is formed, without peeling, spots, or blisters. For low-carbon wire rod, the plasticity declines monotonically, while the strength increases. For high-carbon wire rod, the microstructure is unsatisfactory: tempering sorbite and also bainite and pearlite of reduced dispersity. (The optimum scale consists of wustite.) With increase in coiling temperature (950–1000°C), mechanical scale removal is best, on account of the difference in thermal expansion of the scale and the metal. In storage and prolonged transportation, blisters and scale-free sections may lead to corrosion and, on etching, to overetching of the metal.

The results of investigation of chemical descaling at different temperatures of coil formation both for lowand high-carbon rolled wire are given.

The results of investigation of chemical descaling at different temperatures of coil formation both for lowand high-carbon rolled wire are given.

Two series of experiments on investigation of structure formation in rolled wire of alloy steel of welding function are carried out.

The effect of chemical composition (chromium, nickel, copper, vanadium, molybdenum, nitrogen) and heat treatment regime in a line on weldable reinforcement of strength class 500 structure formation and properties (with respect to yield strength) is considered. High steel alloying efficiency with the above-mentioned elements is demonstrated, in spite of making the steel more expensive. In a number of cases, preparation of a set of structural, mechanical and service properties is only possible with the use of alloying elements, which strengthen steel either by solid solution or dispersion mechanisms.

Short results of the researches, carried out in the conditions of OAO «Moldavian metallurgical works» for recent 25 years and allowed to develop scientifically grounded technological decisions on increase of qualitative characteristics of rolled wire of wide branded grade, are given.

Short results of the researches, carried out in the conditions of OAO «Moldavian metallurgical works» for recent 25 years and allowed to develop scientifically grounded technological decisions on increase of qualitative characteristics of rolled wire of wide branded grade, are given.

The experimental testing of application of fully magnesia casting ladles is carried out with the purpose of reduction of high-carbon steel contamination with nonmetallic impurities. Methods of appraisal of nonmetallic impurities and choice of their rating criteria are analyzed.

Two series of experiments on investigation of structure formation in rolled wire of alloy steel of welding function are carried out.

Improvement in the microstructure and performance of wire rod for the production of high-strength reinforcing cord is considered, To suppress undesirable structures (structure-free cementite and martensite), the use of high-carbon steel microalloyed with vanadium and/or chromium is recommended, as well as thermomechanical treatment of the wire rod.

The development of rolling at OAO Moldavskii Metallurgicheskii Zavod is briefly recounted, with particular attention to the consistent modernization and reconstruction of the equipment and improvement in the rolling technology. New high-quality products have been introduced: thermomechanical reinforcement of strength classes 400–1000 N/mm 2 ; low-carbon wire rod (including alloy steel wire rod) for welding ship hulls, large-diameter pipe, and gas and oil pipelines; and high-carbon wire rod for the manufacture of springs, cable, cord, and reinforcing cable. The design output has been increased by a factor of around 1.8.

Influence of micro-alloying with boron on strain ageing of rolled wire of steel SV-08G2S is shown. A number of experiments on analysis of strain ageing of this steel are carried out

The structure and metallic properties of hot-rolled rolled reinforcement (strength class 400) made from moderate-carbon Si-Mn and manganese steel are analyzed. Thermomechanical treatment is proposed for improvement in these characteristics.

This article examines the hereditary effect of microscopic dendritic segregation in the continuous-cast semifinished product on the structure (the presence of segregation-related striae and martensitic sections and their distribution over the cross section) of wire rod made of high-carbon steel. To improve the quality indices of wire rod, the casting technology should be stabilized by adding equipment for stopper-assisted pouring, fully protecting the stream with submersible refractory tubes, using modern mold-oscillation mechanisms (such as lever-type mechanisms), using parabolic molds that speed up crystallization of the CCS, and employing other measures. Maximum use should be made of heat treatment of the CCSs and rolled products, one of the goals here being to increase the degree of homogenization of the cast structure and rolled product and/or residues of that structure. This can often be achieved through longer heating of the CCS in walking-beam furnaces prior to the rolling operation.

Разработаны химический состав стали по принципу минимизации содержания упрочняющих элементов на нижнем уровне требований НД и заказчиков, регламентировании отношения бора к азоту, что в целом увеличивает пластичность катанки. Дополнительная смягчающая поточная термическая обработка на линии Стелмор обусловливает безотжиговое волочение катанки в готовую омедненную проволоку.