Continuous casters' specific types introduction 02

Characteristics of arc continuous caster

The crystallizer of vertical and vertical bending continuous casters is straight, while the arc continuous caster adopts the arc crystallizer with a certain curvature radius. The crystallizer, secondary cooling device and tension straightening device are arranged on the quarter radian of a circle with a certain radius. The slab has been bent when solidified in the mold. The slab with liquid core is pulled out of the mold, runs along the arc track, continues to spray water for cooling, completes solidification at the quarter arc, and then straightens, pulls out and sends it to the cutting station.

The height of arc caster is only one-third of that of vertical caster, with low construction cost, low static pressure of molten steel, small bulge of slab between rolls and good slab quality; It is also easy to lengthen the body, so it can be poured at high speed and has high productivity. The disadvantages of arc continuous caster are: it is easy to cause internal cracks due to slab bending and straightening; The inclusions in the slab are unevenly distributed, and the inclusions gather on the inner arc side; The equipment is complex and difficult to maintain.

Although arc continuous caster has disadvantages, it is still the most used model in steel mills all over the world due to the technical progress in equipment and technology.

Characteristics of ultra low head continuous caster (oval continuous caster)

The so-called Ultra-low Head continuous caster means that the height of the continuous caster is lower than that of the general continuous caster, and its liquid core pressure head is naturally very low, so it is called Ultra-low Head continuous caster. At present, there is no unified definition standard in various countries. Comcast uses the ratio of caster height h to slab thickness h as an index:

H / H > 50 high pressure head continuous caster

H / h = 40 ~ 50 normal head caster

H / h = 25 ~ 40 low head continuous caster

Ultra low head continuous caster with H / h < 25

The advantages of Ultra-low Head continuous caster include

(1) As the steel hydraulic head is low, the static pressure of liquid steel is small, and the bulge deformation is small. Through calculation, when the radius of continuous caster decreases from R = 10.5m to r = 3M, the strain caused by bulge deformation in the two-phase area of slab is only less than 10%, which improves the slab quality. Due to the small bulge deformation, the pinch roll structure in the secondary cooling area is simplified;

(2) The main equipment of the continuous caster is placed in a horizontal position, which is convenient for maintenance;

(3) The equipment is light in weight and reduces the cost.

However, due to the low pressure head, it is not conducive to the floating of inclusions. Therefore, measures should be taken to purify liquid steel and protect pouring.

This model is suitable for the transformation of old plants. China's Tiangang, Handan Iron and steel, Maanshan Iron and steel and other enterprises have built this Ultra-low Head continuous caster and achieved good production results.