EUROPEAN STEEL TECHNOLOGY AND APPLICATION DAYS 2017 - ESTAD 2017

In November 2015 voestalpine Stahl Linz started up its secondary metallurgy No. 4. This facility consists out of a ladle furnace, a RH vacuum degasser and a trimming stand and is located in the east of the steel plant just opposite to the slab caster CC 7. Already in the early phase of a feasibility study it was decided that this secondary metallurgy will be an investment for the `high end´...

The AOD process is primarily used for stainless steel making since conventional BOF converters lead to high loss of Cr and other alloy elements due to oxidation. During the different operational stages, namely decarburization, reduction and desulphurization, an O2/Ar mixture is fed into the converter via submerged tuyeres that can be located either in the side wall or the bottom. The O2/Ar...

It is well known now that the ingot defects like hot tears or cracks are rooted at the first beginning of the solid shell birth. Damages result from the competition between hydrostatic pressure within the turbulent flow of the liquid zone and the solidifying skin under tensile stresses and strains state. In addition, the thermal energy extracted from the cast product by the mold has huge...

Electromagnetic, mechanical or gas stirring can improve thermal, mechanical and chemical mixing. Bottom gas stirring is the dominant method. Physical modeling has been extensively employed in the past 40 years to describe mixing phenomena due to bottom gas stirring in metallurgical ladles. The opacity of the steel/slag system and its scale are two factors that impose limitations to fully...

The process of liquid steelmaking is characterised by a large throughput of resources and energy. It is performed along a chain of different batch processes performed consisting of several aggregates for heating and metallurgical refining of the liquid steel melt. The objective of the production process is to deliver liquid steel melts with narrow quality targets regarding temperature and...

The meaning of numerical simulations of metallurgical reactors has increased during the last years. The simulations offer detailed information about the process and new insights into regions, which are typical difficult to examine. For the simulated remelting processes the growth direction of the dendrites is most important. The correlation between liquidus isothermal and growth direction...

Outokumpu Stainless Tornio Work is an integrated steel plant, which features production of molten ferrochrome at the same site. The refining of the molten ferrochrome is conducted in an ferrochrome converter, which is essentially a modified argon-oxygen decarburisation (AOD) converter. The process control of the ferrochrome converter is based on composition samples and temperature...

Flow Phenomena and mixing characteristics of the molten metal bath have been investigated according to the bottom bubbling gas conditions. The mixing time of the bath was affected from the location of gas bubbling plugs on the bottom of the ladle and numbers(from 1 to 3 plugs). For the same number of bottom bubbling plugs, the bottom bubbling in the center of the ladle showed the shortest...

In the Tata Steel IJmuiden BOS plant (Netherlands) the Hot Metal pouring process is completely automated. After the connection of the torpedo above the HM pit by the loco driver all movements of torpedo’s and transfer cars are done by computers. Interlocks with loading cranes, avoid overfilling Hot Metal ladles, damaging the torpedo tracks and recognition of the torpedo number are guarded by...

The steel market is experiencing a difficult conjuncture: on the one hand steel producers minimize their investments while optimizing their over- production, on the other hand suppliers reduce their internal human resources and capacity in order to overcome the instability of the new era. A return to the steel production levels of the past is not expected in the short term. Research,...

Effects of the slags on the total oxygen contents and Ds formation in bearing steel were investigated by vacuum induction furnace experiments. The optimal middle basicity slags for VD treatment was selected in the range the CaO to SiO2 content ratio of 3~4, and the CaO to Al2O3 ratio of 1.6~1.8, resulting in lower total oxygen contents and less Ds inclusions. Evolution of inclusions in bearing...

After years of meltshop trials, the final technical solution for a Mechanical Pumping System for Vacuum treatment in Steelmaking has been finalized by SMS group and the pump manufacturing company Flowserve/SiHi. The result of trials and validation processes of the technology are presented in this paper outlining the optimal solution for a series of installations for specific technical...

For the present investigation, the same steel grade has been produced with two different deoxidation practices namely Al and Al-Si killing. There has been reported that deoxidation with Si reduces costs and decreases castability issues associated with Al. Material from both practices has been characterised in the "as cast" and "forged and rolled" conditions. The differences in terms of...

The thin solidifying shell in the meniscus region of continuous caster deforms due to severe contraction of steel during solidification for near peritectic composition of steel and there is potential risk of cracking and in the extreme cases, breakout of shell. The main purpose of the present study was to contribute an improved understanding of peritectic transformation through high...

Laser-induced breakdown spectroscopy (LIBS) is a promising method for fast and quantitative element analysis of complex materials. We report on LIBS measurements of multi-component oxide materials and the compositional analysis of materials by a calibration-free (CF) method. This CF-LIBS method relies on modeling of the optical emission of laser-induced plasma assuming local thermodynamic...

In mid of 2015 Acroni, a Slovenian steel producer belonging to the Slovenian Steel Group (SIJ), has awarded Primetals Technologies with an order to supply a new 95 metric ton AOD converter and dedusting system to its steel works in Jesenice. Less than 2 years later, in April 2017 the new process route will be brought into operation resulting in an increase in annual liquid steel production...

JFE Steel Corporation produces around 0.6 million tons of Cr base ferrite stainless steel per year at the Chiba Works. Recently, the demand of ultra-low carbon grade of Cr base ferrite stainless steel is increasing for using automotive exhaust system parts and so on. In the case of producing ultra-low carbon Cr base ferrite stainless steel, the bottle neck of the production line is Vacuum...

The SMS group vacuum converter technology combines the advantages of the AOD converter and the VOD technologies. In the vacuum converter process, the final decarburization step of stainless steel grades and ferroalloys takes place under vacuum. The dilution of oxygen by inert gases known from the AOD process is largely omitted. Use of SMS group´s vacuum converter technology ensures the...