The ladle lip ring holds the wall (barrel and slagline) tight in compression throughout the ladle campaign and withstand the steel/slag dumping process and associated cleanup of the ladle lip.
Thermal
Peak Temperature:The temperature of the lip is similar to that of the ambient temperature of the air and can be higher due to radiant heat in the process and can rise abruptly at the time of dumping from the steel/slag. Although the lip ring can experience high temperature during ladle overweight and arc heating in the ladle metallurgy area. Thus high temperature resistant materials are to be considered for the application.
Thermal Shock: The thermal cycling for the working lining is considerably high and it experiences shock during the dumping of slagin every heat. Thus it ultimately depends on the number of heats per day (Although the number of heats per day varies from 4 to more than 6 in certain shops).
Mechanical
Impact: The impact is high due cleaning of the lip for dumping skulls or lip skull removal process.
Abrasion:The abrasion on the lip is least. The bath turbulence does not affect the abrasion of the lip. The lip lining suffers from abrasion only at the time of steel/slag dumping in the pot.
Applied stress:The height of the lining is less to cause any applied stress. However, when monolithic material is used, expansion tolerance is to be provided or flexible material is to be used.
Chemical
Dissolution:Wear by dissolution depends on the chemical compatibility of the slags with bricks. The slag gets in touch with the ladle lip only at the time of dumping and thus it is not considered a major wear factor.
Penetration:Penetration is caused by low viscosity metal/ slag or highly wetting metal/slag penetrating into porous refractories. which is not a problem for the slag line area.
Thermo- Mechanical
Strain of thermal expansion-The height of the lining is very less to cause any applied stress. However, when monolithic material is used,expansion stress is generated. Expansion allowance is to be provided or flexible material is to be used.
Chemical Mechanical and thermo mechanical chemical
Spalling of the penetrated zones-This does not apply to the lip ring.
Choice of material
The present practice is the use of precast lip segments with bolts placed into the refractory and holes embedded into the shell. The material used is high-quality 80% alumina or spinel-containing refractory. The material contains stainless steel needles to hold the castable together at the time of any impact damage. The brick is to be replaced when the ladle lip ring gets deformed(warped upwards greater than 75mm) and does not possess enough capacity to hold the bricks in their place.
