Corundum refractory skid rail blocks are designed for demanding high-temperature applications. However, even a suitable refractory material can fail prematurely if the operating conditions, block design, or installation are not properly matched.
When skid rail blocks crack, wear down, or lose pieces, replacing them with the same grade may not solve the problem. It is important to understand what caused the damage first.
1. Thermal Spalling
Repeated heating and cooling can create thermal stress inside refractory blocks. If the stress exceeds the material's resistance to cracking, surface spalling or deeper cracks may develop.
The risk depends on the material composition, microstructure, temperature changes, and heating and cooling conditions. Corundum-based materials can differ considerably in their thermal shock behavior.
What to check: Look at the damage pattern and review whether cracking occurred after a furnace shutdown, restart, or rapid temperature change. If thermal shock is suspected, compare material grades using relevant test data rather than relying on alumina content alone.
2. Excessive Wear at Contact Surfaces
Skid rail blocks may experience repeated contact with moving steel billets or slabs. Iron oxide scale, uneven loading, and localized contact can contribute to surface wear.
High density and low porosity may be useful selection criteria, but they do not guarantee better wear resistance in every application. Material composition, strength, microstructure, and actual operating conditions also matter.
What to check: Identify where wear is concentrated and whether the steel product contacts the block evenly. If damage is localized, review the block profile, loading conditions, and scale accumulation before changing the refractory grade.
3. Cracking Due to Installation Stress
Refractory blocks expand as the temperature rises. Insufficient expansion clearance, unsuitable joint materials, uneven support, or excessive restraint can create stress and lead to cracking or chipped corners.
In some cases, the problem may lie in the installation rather than the refractory material itself.
What to check: Compare the installed blocks with the approved drawings. Review joint clearances, support conditions, and the specified installation method. Expansion gaps and joint-filling materials should follow the furnace design and relevant installation requirements.
4. Attack From Iron Oxide Scale
Iron oxide scale can accumulate on hot refractory surfaces. Depending on the temperature, scale composition, and refractory chemistry, interaction between the deposits and the refractory may contribute to surface deterioration.
The extent of chemical attack varies between applications, so it should not be assumed to be the cause of every damaged block.
What to check: Look for scale deposits and localized surface erosion. Where chemical attack is suspected, reviewing the scale composition and refractory specifications may help identify a suitable replacement material.
How Can Premature Failure Be Reduced?
The same refractory grade may perform differently in two reheating furnaces because operating cycles, mechanical loads, installation details, and scale conditions are not necessarily the same.
Before ordering replacement corundum skid rail blocks, it is useful to prepare:
• Photos of damaged blocks and the affected areas.
• Existing drawings or block dimensions.
• The current material grade, if known.
• Furnace operating temperatures and shutdown history.
• Details of the installation and observed wear conditions.
This information helps narrow down possible causes and determine whether material selection, block geometry, or installation details need further review.
Need Replacement Corundum Skid Rail Blocks?
Luming supplies refractory materials for industrial kilns and furnaces. If you are replacing worn or damaged skid rail blocks, share your drawings, operating conditions, and available photos with our team.
We can review the stated requirements and discuss the information needed to assess a suitable refractory solution.
Contact Luming to discuss your refractory skid rail block requirements.
Product details:https://www.lm-kiln.com/precast-block/corundum-mullite-precast-block/zirconia-corundum-skid-rail-brick-for-steel.html
Email: luming@lm-kiln.com
WhatsApp: +86-18905335290 /+86-18953395199
