Localization of reformer tubes of direct reduction units of Mobarakeh Steel

According to the economic observation report and quoting the public relations of Mobarakeh Steel of Isfahan, Dariush Rashidi said in this regard: Relying on the technical knowledge and experience institutionalized in Mobarakeh Steel and the efforts of domestic construction companies, 22 10 tubes of these reformers are localized and successfully used. Took.

Emphasizing the importance of the quality of this equipment, he stated: “Many imported pipes have become obsolete, and with this success, about one-fourth of the regenerative reformers with pipes made inside the production operation are performing and have had a good performance so far.”

Referring to the benefits of localization of direct regeneration reformer tubes, Rashidi said: “Considering the high price of these parts and their high consumption in the company, the purchase of these tubes is very valuable, but with the localization of these parts, in addition to 7 ٫ 6 million Euros of foreign exchange savings have been achieved for the country, with the cooperation of domestic manufacturing companies in their production process, we have succeeded in acquiring technical knowledge and technology of casting superalloys in a centrifugal method and on an industrial scale in the country.

Mohammad Reza Fathi, head of the direct reduction unit, added: “Reformer pipes and tubes are one of the most important and strategic parts and have the highest financial cost in direct reduction units. The process of breaking methane gas and converting it into the required reduction gases at a temperature of more than 1100 degrees Regeneration of oxide pellets is performed in them. Fortunately, with the approach of Mobarakeh Steel management in the field of localization and the company’s full support of local manufacturers, in this regard, a working group was formed with the presence of specialized and experienced staff and with the cooperation of domestic manufacturers, localization of these sensitive parts was studied and exchanged. Finally, the localization operation was performed in different stages. We must keep in mind that in some parameters, in the imported sample, it was not possible to use it in some temperatures, which in the localized sample, this limitation has been removed. Undoubtedly, it is not possible to achieve both the liberation from dependence and the prevention of the outflow of currency, except by the grace of God and with the effort and confidence in the internal power, which is a source of pride.

Mojtaba Karimi, a repair expert, said: “In previous years, resuscitation reformer tubes were fully supplied by a foreign manufacturer. In addition to high valuation, the impossibility of supply due to the conditions of sanctions was a potential threat to direct resuscitation units.” .

Fortunately, with the investment of the private sector to build the part and continuous cooperation between the manufacturer, resuscitation repairs and the company’s localization unit, the problems of the manufacturing and supply process were solved in the country. Compared to external components, it has good performance in terms of technical parameters such as creep and useful life.

In this regard, Yousef Yelmeh, technician of spare parts for direct resuscitation, said: in the reformers of direct resuscitation units, a total of 4068 10 and 8 inch tubes are working. These tubes are installed vertically in the furnace and inside they are filled with catalysts with the desired specifications. The natural gas is broken down into regenerative gases by passing through the catalyst layers and prepares for the process of regenerating the pellets and turning them into sponge iron. Previously, these tubes were supplied by German, Japanese and Spanish companies with a lot of time and currency, but now the localized parts are delivered in a very short time and at a price incomparable to imported types.

Regarding the process of localization of this equipment, Mosayeb Foroughi, the head of the localization unit of Mobarakeh Steel, also noted: The process of localization of these parts started in 1989. By solving the problems that were on the way to localization of these parts, fortunately, the production of these tubes in the country started and after hot performance testing, 1022 of these tubes have been blessed by domestic companies, casting, machining and delivery of Steel Company. Is.

Due to the lack of centrifugal casting technology of superalloys in the country as well as information about the material and their casting process, first by destroying a sample of these tubes and performing reverse engineering process, chemical analysis, mechanical properties and suitable microstructure for these parts It was found. After that, with the cooperation of the relevant departments, more appropriate information on the appropriate delivery standards for these tubes was collected and compiled.

Hossein Izadi, an expert of the localization unit, also said in this regard: “In general, these tubes consist of three parts: bottom, top and flange. The material of each of these parts is designed and made according to the temperature around them in the furnace.” Each of these parts is connected using automatic plasma welding machines or GTAW welding process and using highly skilled welders.

During and after the production process, various tests including chemical analysis, traction, creep, macrography, metallography, pneumatic and hydrostatic, penetrating fluid (PT), radiography (RT), roughness and broscopy on different parts of these tubes and with attention Complies with the requirements of the technical certificate.

These tubes are subject to very high temperatures (1100 ° C), creep, corrosion and carbon deposition, and due to the long life that is expected of them, they should be made of super alloys with high amounts of nickel, chromium and other alloying elements such as tungsten, niobium. And titanium to be made to have the appropriate microstructure and mechanical properties and to be used at their operating temperature for at least 10 years.

Following this success, Dariush Rashidi, Director of the Ironworks Department, thanked all the production partners, repairers, technical offices of the direct reduction unit, purchasing spare parts and machinery, quality control of spare parts, engineering of parts and equipment and other collaborators who collaborated in this project. کرد.