Enameling steel has important applications in our daily life as in domestic appliances and industry (chemical, agro-food, storage tanks, heat exchangers..etc.) due to its outstanding properties resulting from combined advantages of steel and enamel. The combination of such steel and enamel provides durability and glossy appearance that withstand chemical corrosion, abrasion, thermal shocks and fire. The durability and quality of enameling process depends to a great extent on the quality of substrate (enamel steel). To ensure an acceptable quality of such steel to be enameled, care must be taken during steelmaking and refining such grade to obtain low carbon levels (0.03-0.05%max) and minimum count of inclusions. The morphology of inclusions is adjusted by Ca-cored wire feed technology however melt stirring using Argon is very useful to minimize inclusions and gas contents. Vacuum decarburization of steel melt to ensure low carbon levels prevents the black specks during firing of such steel sheets; however micro-alloying with 0.2-0.5% Ti or V stabilizes the rest of carbon and creates default sites for hydrogen after cold rolling to prevent fish scale phenomena after enameling. Assessment of inclusion counts and their morphology as well as distribution of carbides are carried out using scanning field electron microscopy and ASTM standard.

Continuous casting, initially introduced in 1840, is an attractive method in mass producing semi-finished metal shapes (slabs, blooms, and billets) from molten metal. More than 50% of current world’s steel production is produced by continuous casting. Today, annually 750 million tons of steel in the steelmaking operation, 20 million tons of aluminum and many tons of other alloys are directly cast from molten metal by continuously casting method [1]. This paper presents a short review over the processes in consciously cast steel.

The microstructure of steel is responsible for the macro-behavior of steel or in other words steel’s material properties. Surface microcracks and internal flaws can be introduced to steel microstructure during solidification. The soundness of the steel is altered by formation of flaws and microcracks in casting production line. Additive elements to molten steel and chemical element and alloys in the iron slag may produce indigenous and exogenous inclusions in the microstructure. The presence of the inclusions in the microstructure changes the cleanliness of the steel and affects the material properties of the steel products. This paper is a review of literatures on the sources of formation of inclusions and flaws in the as-cast steel and the effect of these defects on the microstructure properties.

The influence of solution annealing heat treatment on the microstructure and hardness of Hadfield steel containing up to 3.16% chromium and 0.15% nitrogen was investigated.
Furthermore, the effects of chromium additions on the hardness and microstructure of austenitic manganese steels in the as-cast and heat-treated conditions have been studied. The true stress-true strain response of nitrogen alloyed austenitic manganese steel with chromium additions in the as-cast and heat treated conditions under compression loading was also studied. The microstructural observations on the as-cast and heat-treated steels with chromium additions revealed the stability of austenite phase in the as-cast state deformation with precipitation of carbides and carbonitrides on the grain boundaries. These precipitates increase by increasing true strain and chromium content.
2² factorial design was used to investigate the contribution effect of chromium additions and true strain on hardness of austentic manganese steel as cast and after heat treatment. The contribution of both chromium additions up to 3.16%, true strain rate up to 0.4, and the interaction combination effect of them were determined of cast and heat treated austenitic manganese steel. The regression models were built up to identify the hardness as function in chromium additions and true strain rate of both cast and heat treated austenitic manganese steel.

The effect of direct reduced iron (DRI) addition in metallic charge on the different steel making parameters and consumption figures have been studied. Data obtained from industrial heats carried out in 185-ton electric arc furnace (EAF) were used to study. The present study carried out in a wide range of DRI percentage, 0 - 50% of metallic charge, and the results have been statistically analyzed to correlate the percentage of DRI with the different consumption figures of electric energy, oxygen, coke and fluxing materials. In addition, the influence of DRI percentage on contents of tramp and detrimental elements affecting on steel quality has been also investigated.
The results reveal improving the steel quality by increasing DRI percentage, as the tramp elements (Cu, Sn, Ni, Cr) and detrimental elements (P, S) and also nitrogen, all decrease by increasing the percentage of DRI in the metallic charge. On the other hand, the increase in DRI percentage leads to increase in the consumptions (per ton of liquid steel) of electric energy, oxygen, coke and fluxing materials. Furthermore, the metallic yield decreases and the power on time and hence the tap-to-tap time increase as DRI percentage increases. With using higher DRI percentage in the charge, the yield strength and ultimate tensile strength of produced hot rolled bars of low carbon steel slightly decrease whereas elongation increases.

news in steel

LKAB invests in pilot plants for phosphorus and rare earth metals

"We are investing 45 million kronor in pilot plants as part of a pre feasibility study to define a process that enables recycling of mine waste through innovative processing, producing critical raw materials. Lab tests conducted during the year confirmed that we can produce more phosphorus and rare earth metals than estimated," says President and Group CEO, Jan Moström.

Introducing Duroxite™ 200 overlay plate for preventing severe sliding wear

Duroxite™ 200 saves money and improves productivity in a wide range of applications through higher output and less maintenance.

SMS group supplies high-performance Compact Cold Mill to Marcegaglia

Marcegaglia Ravenna S.p.A. has contracted SMS group for the complete supply of a two-stand reversing cold mill of CCM® (Compact Cold Mill) design. Marcegaglia's head-quarters is located in Gazoldo degli Ippoliti, in the Mantua province in North Italy.

VCC® technology comes to Colombia

Ternium del Atlántico SAS, has placed an order with SMS group for the supply and installation of the VCC® technology (Vertical Compact Coiler) for its bar mill in Palmar de Varela, Barranquilla, Colombia.