Thin slab casting

A recent technology development in the production of GO electrical steel is the combination of thin slab casting, direct hot rolling, and acquired inhibitor formation. This practice combines tbe advantages of low temperatures, process-shortening, microstructural homogeneity, improved strip geometry, and better surface condition of the products. The slab thick-... 

J. K. Park J K, et al., Thermal and Mechanical Behavior of Copper Molds during Thin-slab Casting (II) Mold Crack Formation , Metallurgical and Materials Transactions B, 33B (3) (2002), 437-449. 

In the past 20 years, the conventional steel processing route has faced a fierce challenge from the newly developed thin slab casting and direct hot rolling process, which was assisted by the increasing acceptance of the minimill technology. 

With the rapid development of the thin slab casting and direct hot rolling... 

As discussed earlier, slab reheating in the conventional strip process route is achieved by burning natural gas or other fuels in a reheat furnace. In the thin slab casting route, equalization of slab temperature is usually achieved in a natural-gas-combusted tunnel furnace. The common feature in these processes is that the slab is oxidizing in an atmosphere containing a mixture of several gas species. Normally, the furnaces are operated under air-rich combustion conditions, i.e. more than sufficient amounts of air are used to react with the fuels introduced to the furnaces, and therefore, when in equilibrium, the... 

Rolling step Conventional Thin slab casting -direct rolling Castrip process... 

R. Y. Chen and W. Y. D. Yuen, Copper enrichment behaviours of copper-containing steels in simulated thin-slab casting processes , ISIJ Int. 45, 807-816 (2005). 

For various reasons, including financial ones, the United States was slower than Japan and Europe to install continuous slab casters for the production of sheet. Electric melters cast billets continuously from about 1975 onward. Casting was done cmdely at first but the sophistication increased rapidly, culminating in the operation of a thin-slab caster at one of Nucor s plants. This opened up another avenue of attack on sheet markets, once the province of integrated mills. 

This logical extension of thin slabs to cast direcdy to sheet in the 1-mm range is a possibiUty long recogni2ed but difficult to reali2e. Progress in both stainless and carbon steel has been rapid and early prototypes are expected by the year 2000. Several schemes have been tried in laboratories all over the world. 

In a typical CSP process, as schematically shown in Fig. 8.2(a), liquid steel produced by an EAF process is cast to 50-90 mm thick slabs (one-third to one-fifth the thickness of slabs produced by conventional casting) [8]. The thin slab is then transferred through a tuimel furnace where the temperatures throughout the slab body are equalized. The tunnel furnace is normally kept... 

Sheet and Strip. The manufacture of wrought copper materials starts with either semicontinuously cast slabs that are hot roUed, or cast plate that is thin enough, near 13 mm (0.5 in.), to be cold roUed directly. The surfaces of both hot roUed slabs and as-cast plate are milled to remove defects before proceeding to cold rolling and annealing operations. 

Metals that have been produced by pyrometallurgical methods, such as copper, silver, nickel, and tin, are too impure for many purposes, and electrorefining is used to purify them further. Crude metallic copper is cast into slabs, which are used as anodes in electrolysis cells that contain a solution of CUSO4 in aqueous H2SO4. Thin sheets of pure copper serve as cathodes, and the copper that dissolves at the anodes is deposited in purer form on the cathodes (Fig. 17.18). Impurities that are more easily oxidized than copper, such as nickel, dissolve along with the copper but remain in solution elements that are less easily oxidized, such as silver and gold, do not dissolve but fall away from the anode as a metallic slime. Periodically, the anode slime and the solution are removed and further processed for recovery of the elements they contain. 

Bond strength between PC overlays and portland cement concrete substrate was measured using the pull-out test method [7], The tensile bond test is illustrated in Fig. 1. Specimens were thin overlays, about 1/2-in. (1.3-cm) thick, cast directly (without the use of a primer) on sandblasted portland cement concrete slabs. Circular grooves (4-in./10. 8-cm diameter) were cored through the overlays and into the portland cement concrete substrate. Circular steel disks... 

Purification of metals is another important application of electrolysis. For example, impure copper from the chemical reduction of copper ore is cast into large slabs that serve as the anodes for electrolytic cells. Aqueous copper sulfate is the electrolyte, and thin sheets of ultrapure copper function as the cathodes (see Fig. 18.23). 

Hitherto, gel electrofocusing has been carried out in thin layers and troughs, or else in narrow tubes. Very thin layers have been used by Awdeh et cU. (39), as well as by Catsimpoolas (28). Leaback and Rutter (37) used a special trough for casting slabs of polyacrylamide. The latter method permits a certain amount of preparative work. Riley and Coleman (30) also used thin layers. 

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