Background

The steel industry has benefited from the economic benefits of steel fibre reinforced refractories for over two decades. At both integrated and Electric Arc Furnace steel plants there are many refractory applications which benefit form the addition of fibres reinforcement.

Fibretech offers a range of stainless steel fibre alloys to meet the requirements of individual applications including fibres which withstand hot face temperatures of up to 1400-1500°C.
Refractory Trends in the Steel Industry

As the steel industry moves away from the use of bricks to monolithic refractories the use of stainless steel fibres is ever increasing. Furthermore the growing importance of rapid and safe refractory installation has seen a rise in the use of shotcrete and gunning materials. Fibretech's ME fibres are ductile at room temperature and are therefore used successfully to reinforce sprayed refractories.
Continuous Casting

The addition of stainless steel fibres to continuous casting refractories can be of great benefit. Two regions where this has been found to be of use are the teeming ladle and the tundish. These two regions will be explored in more detail below.
Beneficial Properties of Stainless Steel Fibre Additions to Refractories for Continuous Casting

Fibretech supplies a unique range of stainless steel fibres for continuous casting refractories offering:

· Improved Refractory Performance

· Lower Installations Costs

· Better Operating Efficiency

· Lower Refractory Costs

· Increased Operating Plant Availability
Teeming Ladle

Application


Benefit of Stainless Steel Fibre Reinforced Refractories


Recommended
Fibre

Cover


Castables in this application often crack quickly and spall due to repeated thermal cycling increasing heat loss, energy consumption and damage to shell steelwork. A fibre reinforced insulation castable combines efficient insulation with excellent mechanical strength, so is better able to reduce maintenance and energy costs.


ME 430

Lip


Fibres extend the lip's working life whilst reducing downtime and maintenance costs. A fibre reinforced lip also helps hold the security and bricked linings tight so the lining remains safely intact and in service longer.


ME 446

Security Lining


Without fibres in the security lining, cracking caused by thermal expansion and mechanical shock can shorten the effectiveness of the lining thereby increasing the risk of a hot metal run through. Fibres remove this and provide a longer ladle campaign and reduced downtime and maintenance costs.


ME 446

Impact Pad


Similar to the tundish impact pad, this suffers repeated thermal shock during its life. ME fibres at 3-4% by weight, can improve performance considerably, reduce downtime and cut refractory material and Installation costs.


ME 446

Porous Plug and Nozzle


A fibre-reinforced plug or nozzle has increased service life over other designs. Even when cracked or spalled the refractory is held tight, maintaining a consistent shape, improving durability and reducing production costs.


ME 446

Refractory Shroud


Maintaining casting temperature and minimising oxygen inclusion are vital to steel quality and production efficiency. A fibre-reinforced refractory shroud combines excellent insulation with superior durability in a sometimes vulnerable, crack-prone refractory shape, keeping production costs to a minimum.


ME 446

Seating and Well Blocks


Seating and well blocks for teeming ladle nozzles and porous plugs are expensive consumables. Since a fibre-reinforced block can often last as long as the bottom lining, fewer replacements are needed, so returning important savings in energy and maintenance costs.


ME 446



AZoM - metals, ceramics, polymers and composites : stainless steel fibre reinforced refractories used in a teeming ladle in continuous casting.

Figure 1. Schematic of a teeming ladle used in continuous casting.
Tundish

Application


Benefit of Stainless Steel Fibre Reinforced Refractories


Recommended
Fibre

Nozzle


Like the teeming ladle, only if a nozzle remains in one piece and does not crack can it perform consistently and keep the tundish in service. A fibre-reinforced nozzle resists cracking and spalling, outperforming other designs while reducing the incidence of a blockage.


ME 446

Security Lining


A conventional refractory lining can quickly crack due to the differential expansion of the shell thereby increasing the risk of hot metal run-through. Slagline erosion is also a problem. A fibre reinforced low cement castable resists this cracking and erosion and holds the refractory intact eliminating the possibility of a run-through.


ME 446

Impact Pads


This precast shape suffers repeated thermal shock during its short life. ME fibre at 3-4% by weight can improve performance by 100% or more. Refractory consumption can be halved and tundish downtime significantly reduced.


ME 446

Covers


Refractory lined tundish covers help maintain casting temperature. Radiant heat and slag attack however crack the refractory, reducing its insulation properties. A fibre reinforced castable is more resilient and so reduces maintenance costs.


ME 446

Tundish Baffle Walls


The strength and performance oftundish baffle walls will be enhanced with ME fibres. Their normally thin wall section is particularly crack-prone, but fibres can inhibit this cracking, bind and hold the castable together and prolong the service life.


ME 446

Refractory Shroud


Maintaining casting temperature is vital to steel quality and production efficiency. A fibre-reinforced refractory shroud combines excellent insulation with superior durability in a sometimes vulnerable, crack-prone refractory shape, keeping maintenance and energy costs to a minimum.


ME 446