TRADITIONS IN DEVELOPMENT

The processes taking place lately in the world, including the fall in oil prices, increase the importance of the non-oil sector development. In this context, the progress of metallurgy - the fundamental pillar of the entire industry - is a very important factor for the development of the economy as a whole. However, unfortunately, in the recent period there is an unjustified belief in society that metallurgy in Azerbaijan is in its infancy, while the metallurgical industry of the country has a long history rich in traditions.

Metallurgy covers all areas of our life, and Azerbaijani metallurgists, engineers and scientists made a considerable contribution to the economy and development of this industry in the Soviet period. So, Azerbaijani Cingiz Ildirim once laid the foundations of the Magnitogorsk metallurgical plant in Russia and managed it for a long time (the entire technological process was carried out here - from the extraction and enrichment of iron ore to steel production). Along with other metallurgical and machine-building plants in Azerbaijan, the Sumqayit Tube Rolling Plant operated for a long time, producing more than 800 thousand tons of products per year and supplying the Soviet Union with high-quality oil compressor piping. However, after the collapse of the Soviet Union, the domestic steel industry, like other industries, was in a deplorable state.

Only after return of the National Leader Heydar Aliyev to power, did the industry start to recover. From the moment Heydar Aliyev initiated the founding of the first private steel plant Baku Steel Company and participated in its inauguration in 2001, the revival of the Azerbaijani metal industry began. In recent years, as a result of reconstruction and significant financial investments undertaken by the company's management, Baku Steel Company LLC (BSC) has not only become the largest steel mill in the Caucasus, but has also risen to a level comparable with the most advanced factories in Europe. In order to reduce the cost of production, the company, along with the implementation of reconstruction and modernization, is mastering the latest manufacturing technology.

As an example, we can cite the purchase from the German company Siemens VAI of a new, fully automated electric arc furnace, which is equipped with a combined supersonic oxygen burners and carbon injectors. This steel-making furnace has the EBT bottom-tapping system for molten steel. To refine steel in an inert atmosphere outside the furnace, a more modern ladle-furnace has been purchased and a contract has been signed for a combined (Power-Mold, Fast-castcube-FCC) casting machine that meets the latest technological requirements, has a high casting speed (5m/min) and is equipped with a system of electromagnetic stirring in molds. The updated gas treating plant for collection of dust and gas that occur in production process has a double capacity, which makes it possible to prevent contamination of the environment and comply with all environmental standards. Analogues of this treatment system are installed at several leading European steel works - at the Austrian VOESTALPINE, which is near the city centre of Linz, German Badische Stahlwerke located near the River Rhine, not far from Strasbourg, France, etc.

Along with increasing its production capacity to 1m tons per year, the company has also expanded its product range. Now Baku Steel Company LLC produces not only reinforcing bars and square billets, but also angle bars, channels, double tees and rods of various sizes. In the near future it is planned to produce round blooms for pipe production. The BSC is able to fully meet the demand for these products on the domestic market, producing goods in accordance with the quality requirements of the ISO 9001-2008 standards system.

Due to increasing demand for scrap metal and its chronic shortage in the country, the company is faced with the need to take steps in search of alternative raw materials. As a result, a contract was recently signed with the Italian company Danieli for purchase of the equipment for constant filling of the furnace with ferroalloys and DRI/HBI (products of the direct reduction of iron ore). This installation makes it possible to increase the use of DRI/HBI delivered from Russia and Iran to 80 per cent of the total production capacity and thus reduce dependence on the shortage of scrap metal. We would like to note here that the iron ore reserves in the Islamic Republic of Iran total 7bn t and in Russia - 201.1bn t. The above contract also provides the purchase of two robot units, which will take samples of liquid metal in the process of melting to analyze the chemical composition and measure the temperature of melted steel. This measure is another step forward in the sequential rise of the health and safety level.

Unfortunately, erroneous assumptions have been put forward that the reinforcing bars manufactured by Baku Steel Company LLC are of lower quality since they are made from scrap metal rather than from products of direct reduction (DRI/HBI). But before giving an explanation of the chemical-technological process, we would like to note that those who voice this misinformation are certainly not competent in this field, for metallurgists, i.e. those who are seriously engaged in this subject, will never say that the reinforcing bars used in the construction of multi-storey buildings should be made entirely from DRI. For clarity, we cite the requirements for steel reinforcement in a separate insert.

Neither the GOST 10884-94 and GOST 52544-2006 standards (these standards were ratified by Milli Maclis of the Azerbaijan Republic and regulate the requirements for reinforcing bars in the country and in the CIS) nor similar standards DIN 488 (Germany), BS 4449 -97 (UK), ASTM A615 (USA) or any other standards note the need to use only scrap metal or DRI as raw material. Another requirement for reinforcing bars, as well as all steel products, is the corresponding number of non-metallic compounds, which is also governed by regulations.

Today steel melting technologies are still bound to produce metal containing non-metallic compounds. They are present in any type of steel depending on the composition and production conditions. The amount of them is usually no more than 0.1 per cent.

Non-metallic compounds in steel are foreign bodies, which destroy the homogeneity of its structure; their impact on mechanical and other properties may therefore be considerable. When metal fatigue occurs during the rolling and forging and so forth, the non-metallic inclusions with their sharp edges and corners act as tension concentrators and may cause crack formations, which are a source of subsequent corrosion of steel. 

In order to study the effect of non-metallic compounds on the quality of steel, it is important to study their properties: the size, shape, chemical and physical characteristics, chemical composition as well as the nature of their distribution towards the cast metal grains. The above-mentioned properties of non-metallic compounds depend on chemical composition of steel, method of melting, and, for a set steel grade, may change within extensive parameters, even if a similar production technology is applied.

At present, various methods have been developed and are commonly used, allowing the composition, structure and content of non-metallic compounds in steel to be determined with a high degree of precision, both when they are extracted from liquid metal and in solid steel. The main method of their content monitoring is analysis of the material by using light microscopy on macro- and micro-sections. This analysis is systematically carried out in our laboratories.

Compared to other methods, processing of molten steel by inert gas (Ar), which is done out of the furnace and is one of the latest achievements in metallurgy, produced a more effective result in cleaning metal from non-metallic compounds. Although reinforcing bars belong to the group of common steel grade and requirements on non-metallic compounds applied to such products are less strict than to those of high-quality (alloy) steel, Baku Steel Company LLC still found it necessary to buy such an installation. Thus, processes of desulphurization, dephosphorization, deoxidation and alloying occur precisely in it.

All this shows that scrap metal supplied for secondary processing (it had previously undergone a purification process) contains much less of such non-metallic compounds than DRI, while DRI is rich in such compounds. Many people mistakenly think that DRI is 100-per-cent pure iron. For clarity (Table 1), we cite the composition of DRI, which is known throughout the world.

As it's clear from the table, the best DRI metallization result, when the reduction process was very good, is (Femetal) 85-87 per cent, and the rest of the content make non-metallic oxides (SiO2, CaO, etc. Al2O3) and sulphur (S) and phosphorus (P), which are considered harmful impurities. Their removal from steel is a very serious factor in the technological process affecting the quality.

The basic composition of the recycled metal used for melting steel in an electric arc furnace is carbon steel. The total chemical composition of scrap metal is presented in Table 2.

On top of all, it should be noted: the opinion that "all that is made of scrap metal is bad and everything made of DRI is good" is an incorrect and unreasonable approach. On the contrary, it is much easier to achieve the specified quality parameters by using scrap metal.

We would also like to add that the Turkish Republic produced 34.2m t of steel in 2013, and all reinforcing bars from this production volume were made entirely from recycled materials. In addition, there is no DRI/HBI production in Turkey. The Federal Republic of Germany in 2013 released 42.6m t of steel, and only 1m t of it was produced from DRI/HBI. In Germany only at Hamburg Stahlwerke there is Midrex, a plant for iron reduction. All other re-bar producers in Germany leaded by Badishe Stahlwerke (its production capacity is 2.2m t) make reinforcing bars from metal scrap. 

In general, in 2013, 1,607,200,000 tons of steel products were made in the world, and only 76m tonnes of them were made from DRI/HBI. Following the logic of people with negative attitude to use of scrap metal, hundreds of millions of tons of such reinforcing bars produced in the world are of poor quality because they contain no DRI/HBI. Meanwhile, last year, more than 600m t of steel products in the world were made just of scrap metal used as raw material.

Baku Steel Company LLC, which aims to increase the range of products, carefully studies its potential competitors in the region. In this regard, it should be noted that among the states bordering with us, only Russia, Turkey and Iran are the largest metallurgical countries. Thus, the average performance of steel for these countries is as follows: Russia - 70m, Turkey - 34m and Iran - 15m tons. Iran plans to increase its annual steel production capacity to 50m t. Having rich ore reserves (the composition of iron in ore reaches 50-55 per cent here), Iran started construction of 7 large steel mills last year. Considering this and many other factors, before building new steel plants, we must carefully examine the local market and closely analyze what industry giants we will have to compete with in the region and what kind of steel products will be in greater demand.

In Azerbaijan, metal industry has a rich history, and today on the example of Baku Steel Company LLC, we can see how far domestic metal industry has advanced. As a specialist working in this industry, I strongly believe and hope that thanks to the successful policy pursued by President Ilham Aliyev, heavy industry will continue to thrive while Baku Steel Company LLC, as its flagship, will play an important role, opening new chapters of achievements in this field.

 Requirements for steel reinforcement:

1) Reinforcing bars, as well as other building materials belong to the group of common grade steel.

2)The requirements for this material are governed, like other commodities, by relevant standards, and none of these standards specifies the raw material, i.e. DRI/HBI or scrap metal, to be used for re-bar production.

3) According to the requirements strictly put forward by relevant standards for construction reinforcement, the goods must have the following characteristics:

- Yield strength, Rt, Н/мм2

- Ultimate strength, Rm, Н/мм2

- Extension strain, *,per cent

- Bend test

- Tensile strength

- Relevant geometric parameters

By their chemical composition, non-metallic inclusions are divided into the following groups:

- Oxides (FeO, SiO2, Al2O3)

- Sulphides  (FeS, MnS etc.)

- Nitrites  (Fe4N, Fe2N)

- Phosphides  (Fe3P)