monoblock stopper rod for steel industry

A monoblock stopper rod is an isostatically produced one-piece alumina graphite rod. The rate of flow of the molten steel is defined by the relative position of the stopper nose to the seat of the tundish nozzle. Optimisation of control is achieved through the complementary geometries of the stopper nose and the tundish nozzle or SEN seat. There is a wide variety of stopper nose profiles, each having different degrees of sensitivity and controllability of steel flow to meet the wide range of customer requirements.

Stopper nose profiles range from rounded (bull-nose) designs, through multi-radius (bullet-nose) designs to more pointed (pencil-nose) designs. Round-nose stoppers are normally used on slab casters where there are large throughputs of steel and fine control is not required. On the other hand, a pencil nose is generally used on billet casters where steel flow rates are lower and finer control is required. As well as the shape the composition of the stopper nose can also be varied depending on the type of steel grades and the casting conditions. Foseco have a range of stopper nose recipes to suit customer requirements.

Where alumina build up in the submerged entry nozzle is a problem, argon can be introduced into the steel via a small hole or porous element in the stopper nose. The argon is introduced into the top of the stopper rod by means of a number of different designs and techniques.

Application:

The stopper is positioned above the tundish nozzle and attached to the stopper control mechanism by a threaded steel rod secured with threaded nuts and washers. These threaded steel rods are secured to the stopper rod by a number of means. Steel flow from the tundish to the mould is controlled by an up and down movement of the stopper rod via the control mechanism. The steel flow is then metered into the mould and can be controlled manually or automatically.

Function:

The stopper rod is key to the accurate control of steel from the tundish to the mould for the purpose of maintaining a consistent level of steel in the casting mould. High performance is essential to ensure that casting is not disrupted due to loss of control of steel flow or stopper failure. Correct design, high quality and correct choice of materials is essential for high sequence casting.

Benefits:

1.Highly resistance to thermal shock.

2.Resistance to physical and chemical erosion.

integrity glaze protects the stopper from oxidation during preheat.

strength at temperature.

5.Suitable for all grades of steels utilising zoning with more erosion/corrosion resistant materials.

6.Symmetrical or profiled stopper nose available, either solid or with argon injection capability.

range of fixing systems available.