Runner brick refers to a hollow refractory brick which is masoned at the groove of bottom plate for ingot casting. Its function is connecting king brick and steel ingot mold, so molten steel or iron can be transported into corresponding molds and casted into different shapes. Runner bricks are rectangular special shaped firebricks with many specifications and dimensions. Commonly used runner bricks are clay runner bricks and high alumina bricks. To reduce the friction during the flow of molten steel and prevent steel leakage, the inner wall of the runner brick should be smooth, with tight joint. Based on steel species, output and craft requirement, runner bricks can be divided into central hole king bricks, double holes king bricks, 3 holes king bricks, 4 holes runner bricks, tail bricks and so on.
Runner Bricks Characteristics
Widely used in various types of steel casting (including stainless steel and different kinds of alloy steels).
High refractoriness, good cracking resistance and strong corrosion resistance.
Regular and intact shape, smooth inner hole, accurate size.
Good high temperature performance, scouring resistance, deformation resistance and spall resistance.
Runner Bricks Physiochemical Index
Item
Clay runner brick
High alumina runner brick
Al2O3 %
≥ 42
≥65
Fe2O3 %
≤ 2.5
≤2.5
Refractoriness ℃
≥1680
≥1780
Apparent Porosity(%)
≤24
≤25
Bulk Density (g/cm3)
≥2.20
≥2.25
Cold Crushing Strength Mpa
≥25
≥45
Refractoriness under load ℃ （0.2Mpa）
≥1390
≥1450
Interaction Between Runner Brick And Molten Steel
With the increasing demand on steel quality, cleaning steel production is more and more popular. Generally speaking, oxygen, sulfur, phosphorus, hydrogen, nitrogen and other non-metal impurities are the main factors affecting the purity of steel. There is a direct relationship between the refractory material used for steelmaking and the purity of steel. Runner bricks are usually used in bottom casting method, they contact with the molten metal directly and suffers severe scouring and chemical corrosion, which seriously affects the quality of the casted products. So the quality of runner bricks has great influence on the quality of cast steel.
RS brand clay runner bricks and high alumina bricks with good scouring resistance and erosion resistance are widely used by lots of customers. From numerous production experiences, they are proved to have better performance.
