Basics of Continuous Casting of Steel Jan25

Basics of Continuous Casting of Steel...

Basics of Continuous Casting of Steel Continuous casting is the process whereby liquid steel is solidified into a semi finished product for subsequent rolling in the finish rolling mills. Continuous casting of steel was conceived and patented in 1865 by Sir Henry Bessemer, but it could not be commercialized because of problems related to engineering and equipment. After solving these problems, continuous casting of steel was introduced commercially in 1950s and around 1475 million tons of continuous cast steel was produced globally in 2012. Continuous casting has replaced several steps during steel making process such as ingot casting, mould stripping, heating in soaking pits, and primary rolling with one operation. Continuous casting of steel has helped to achieve improved yield, quality, productivity and cost efficiency. The principle of continuous casting is shown in Fig. 1. Fig 1 Principle of continuous casting Referring to Fig 1, Liquid steel in the steel teeming ladle (1) from the secondary steel making unit is taken to the continuous casting machine. The ladle is raised onto a turret that rotates the ladle into the casting position above the tundish (3). Liquid steel flows out of the ladle into the tundish, and then into a water-cooled copper mould (5). Solidification begins in the mould, and continues through the roll support (6) and the turning zone (7).  The continuous cast strand is then straightened, torch-cut, and then discharged for intermediate storage or hot charged for finished rolling. Depending on the product end use, various shapes are cast. In conventional continuous casting machines these are slabs, blooms or billets. In recent years, the melting, casting, and rolling processes have been linked while casting a shape that substantially conforms to the finished product. These near net shape cast sections are usually applied to beams...