<p>Modern steel production cannot be imagined without manganese, because almost all steels contain<br />manganese.<br />In this paper, we present the impact of manganese on the tensile strength values of high-carbon steel.<br />This paper presents an improvement in the quality of wire rolling with control of manganese content in<br />steel and the value of C-equivalent, in industrial conditions, which is of particular importance in the<br />production of this quality of steel.<br />For the presented quality of rolled wire made of high-carbon steel, it is possible to control the C-equivalent<br />in high-carbon steel to achieve values for tensile strength in exceptionally narrow tolerances of 1000 &plusmn; 30<br />MPa.</p>

Steel X8CrNiS18-9 (standard EN 10088-3: 2005) is the most commonly used from the group of austenitic stainless steel in terms of machinability. The content of sulphur present in the steel from 0,15 to 0,35% has the exclusive task to improve the machinability. However, while sulphur improves machinability it simultaneously reduces the resistance of steel to corrosion but also affects the decrease in mechanical properties particularly steel toughness. Due to its harmful effect on the steel, as well as the fact that the non-metallic inclusions are insufficiently tested for this type of high-alloy steel the aim of this study is to determine the appropriate microalloying possibility to modify the non-metallic inclusions. The aim of this work is that explore the influence of boron, zirconium, and tellurium on the impact toughness of the mentioned steel. Change of impact toughness, depending on the chemical composition of the steel is simulated with the Matlab program.

Sulphur in steel is an undesirable element because it lowers all technological and uses values of steel products. During the steelmaking process, the desulphurization process depends on the thermodynamic conditions, the used desulphurizes, and the stability of the formed sulphides. The desulphurization technology in the production of low-carbon steel in a protective atmosphere, with the addition of synthetic slag and strong desulphurizing agents with additional argon blowing, is presented in this paper. The reduction of sulphur content achieved in the induction furnace is an important contribution to the technology of the production of low-carbon steels.

Tungsten belongs to group of refractory metal that possess extraordinary resistance to heat and wear and it is the heaviest engineering material. Because of its properties tungsten is used for special purposes. This paper presents the results of mechanical and microstructure research on the example of the characteristic heavy tungsten alloys 91W-6Ni-1.8Fe-1Co and 93W-5Ni-1.6Fe-0.3Co with different Ni/Co ratios. The proper Ni/Co ratio is important to obtain a favorable microstructure and mechanical properties of these materials. The distribution of the W, Ni, Co and Fe elements in tungsten phase and binder phase, which can influence on mechanical properties of tungsten alloys. The SEM analysis and mechanical results show that the alloy, which has Ni/Co within the given limits,  posses a finer microstructure and better mechanical properties that is very important for the maintenance of the quality of tungsten alloys for special purposes.

Stainless steel X8CrNiS18-9 (standard EN 10088-3: 2005) is the most commonly used austenitic stainless steel due to its good machinability. This steel has high mechanical and working properties thanks to complex alloying, primarily with the elements such as chromium and nickel. The content of sulfur present in the steel from 0.15 to 0.35% improves machinability. Microalloying with tellurium and zirconium (individually and in combination) in most cases leads to improved properties of this stainless steel, compared to melt without alloying additives, e.g. the melt microalloyed with tellurium and especially melt microalloyed with zirconium and tellurium has significantly better machinability compared to the melt without alloying elements. The addition of sulfur, which is the cheapest available additive for free machining, will impair not only the transverse strength and toughness but also the corrosion resistance. However, while sulfur improves machinability at the same time decreases the mechanical properties, particularly toughness. This work aims to test the machinability, corrosion resistance, and mechanical properties of the mentioned steel, as well as the chemical composition of non-metallic inclusions.

More recently a modified stainless steels have been used to produce various structural elements that work in complex operating conditions. Stainless steel X8CrNiS18-9 (standard EN 10088-3: 2005) is the most commonly used austenitic stainless steel due to its good machinability. This steel has high mechanical and working properties thanks to a complex alloying, primarily with the elements such as chromium and nickel. The content of sulphur present in the steel from 0.15 to 0.35% improves machinability. However, while sulphur improves machinability at the same time decreases the mechanical properties particularly toughness. The addition of sulphur, which is the cheapest available additive for free machining, will impair not only the transverse strength and toughness, but also the corrosion resistance.The aim of this work is to determine the influence of microalloying with boron on the machinability, corrosion resistance and mechanical properties the mentioned steel, but alsoto determine the effect of microalloying with boron on above steel, which is already microalloyed with zirconium, tellurium, or both elements (zirconium and tellurium) due to modification of non-metallic inclusions and improvement of properties.

The influence of the production method, i.e. casting technology on the cleanliness and thus the quality of carbon steels is best determined through the presence and type of non-metallic inclusions. A large number of inclusions, especially oxide and complex ones, can significantly affect the mechanical properties of carbon steels and limit their application for the production of finished products. This paper presents the influence of the presence, type and amount of non - metallic inclusions in B500B carbon steel according to ASTM / AISI produced by continuous casting technology without and with the application of stream protection.

More recently a modified stainless steels has been used for production of various structural elements that work in complex operating conditions. Steel X8CrNiS18-9 (standard EN 10088-3: 2005) is the most commonly used from the group of austenitic stainless steel in terms of machinability. The content of sulphur in the steel from 0,15 to 0,35% has the exclusive task to improve the machinability. However, while sulphur improves machinability it simultaneously reduces the steel corrosion resistance, but also affects the decrease in mechanical properties particularly steel toughness. Corrosion resistance tests of X8CrNiS18-9 stainless steel samples were performed on the potentiostat / galvanostate PAR 263A-2. The aim of this work is that determine the influence of boron, zirconium and tellurium on the corrosion resistance of the mentioned steel. Change of corrosion resistance, depending on the chemical composition of the steel is simulated with Matlab program.