Tundish Dry Vibrating Mix, Spray Coating & Gunning Mix — Working Lining Refractories for Continuous Casting
A tundish only has one job between heats: hold clean, correctly tempered steel long enough for the mould to do its job, without the lining itself becoming the contamination source before liquid steel discharges through anti-clogging zirconia-core metering nozzles. The three unshaped materials on this page are not interchangeable substitutes for each other — they are three different answers to three different failure points in the same vessel, and a procurement spec that treats them as one line item is usually the spec that produces a mid-sequence breakout call. This page covers what each material actually does inside the lining, the physical and chemical indicators that predict how it will behave in your sequence, and what we need from your side to design a lining system around your actual casting conditions rather than a catalog default.
Why Tundish Linings Fail Before the Sequence Is Finished
Tundish lining failure is rarely one mechanism. It is usually two or three running at the same time, and the material that fixes one makes another worse if it's picked for the wrong reason.
Impact Erosion at the Pour Point — Not Uniform Wear
The area directly under the ladle shroud (long nozzle), where the incoming steel stream first strikes the lining, wears at a rate that has nothing to do with the rest of the vessel. A dry vibrating mix sized correctly for the sidewalls can still lose 15-20mm of face thickness at the impact pad in a single long sequence while the rest of the lining shows almost no wear. Engineers who spec one uniform lining thickness across the whole tundish are usually solving for the average wear rate, not the worst-case local rate — which is exactly where the breakout risk lives. Deploying an engineered tundish impact pad and turbulence inhibitor prevents localized bottom washouts.
Thermal Cycling Between Heats — Where Spalling Starts
Every ladle change cools the exposed working face before the next heat reheats it. A lining material with the wrong thermal expansion match to its bond system will develop surface crazing after 3-5 cycles, and crazing is not cosmetic — it's the entry path for steel and slag infiltration into the body of the lining. This is the mechanism that separates a dry vibrating mix that lasts a full campaign from one that needs an unplanned reline halfway through.
Slag Line Infiltration and Chemical Attack
Mold powder carryover and ladle slag concentrate at the steel/slag interface inside the tundish, and low-grade or wrong-chemistry lining material gets chemically dissolved at that line faster than it wears mechanically. This is usually where procurement buys on MgO% alone and gets a lining that looks fine on paper but fails exactly at the slag line in practice — the chemistry match matters more than the headline MgO number.
Three Materials, Three Jobs — Not One Product Line
Tundish Dry Vibrating Mix — The Working Lining Body
This is the main lining material for the majority of tundish designs: a magnesia-based unshaped mix installed by vibration against a form around the nozzle well blocks, monolithic stopper rods, and metering nozzles, then fired in place by the first heat of the campaign. What makes dry vibrating mix different from a poured castable is what happens during that first heat — the face in direct contact with steel sinters into a dense, low-porosity working layer, while the material further from the steel stays semi-sintered or unsintered, acting as an insulating buffer against the permanent lining. At the end of the campaign, the unsintered backup layer is removed with the sintered shell, and a fresh layer is vibrated in for the next campaign — this in-situ, self-forming structure is why dry vibrating mix remains the default choice where turnaround time between campaigns is the limiting factor, not material cost.
Tundish Spray Coating — Thin-Layer and Fast-Cycle Lining
Spray coating is applied wet, by spray gun, directly onto the permanent lining or onto a bond coat, building a working face in a layer roughly a third to half the thickness of a dry-vibe lining. It sets up for service faster than a fired-in-place dry vibe lining and is the more common choice for continuous casters running shorter sequences, where the labor and downtime cost of a full dry-vibe reline doesn't pay back against the shorter campaign length. We also see it specified as the working lining of choice on tundish car designs where vibration access for dry-vibe installation is physically constrained.
Tundish Gunning Mix — Hot Repair Without a Full Reline
Gunning mix is the material that keeps a sequence running when the impact pad or a local hot spot wears ahead of the rest of the lining. Applied by gunning machine directly onto the worn face — hot, without cooling the vessel — it patches the local wear zone in minutes, not the hours a full strip-and-reline would cost. The adhesion bond to the existing worn lining, not the bulk strength of the cured patch, is the number that actually determines whether a gunned repair survives the next few heats or spalls off in the first thermal cycle.
What We Supply — Complete Tundish Lining System or Individual Materials
We supply dry vibrating mix, spray coating, and gunning mix as a matched system, or as individual materials against your own existing spec — whichever your procurement process requires.
Free Mix Design Based on Your Actual Working Conditions
Steel grade, sequence length, tundish geometry, and ladle-to-tundish practice all change which chemistry and particle sizing actually perform in your vessel. Send us your working data — steel grades cast, average and maximum sequence length, tundish capacity, current lining thickness and wear pattern — and our technical engineers will design a mix specification around those numbers rather than hand you a standard catalog grade and leave the fitting problem to you.
Free Samples for Trial Before You Commit to Volume
A technical data sheet tells you what a material should do under standard test conditions. It does not tell you how it handles your shroud geometry, your reheat cycle, or your specific slag chemistry. We supply free samples sized for a genuine trial installation so your own engineers can validate performance before any production-volume order is placed.
On-Site Engineer Support for Installation and Maintenance
Our technical engineers are available to travel to your plant for lining installation guidance and ongoing maintenance support — correct vibration technique and form removal timing for dry vibrating mix, spray application parameters for coating work, and gunning technique for hot repairs all materially affect service life, and getting them wrong on the first few campaigns is the most common reason a good material underperforms its TDS numbers.
Tundish cross-section schematic detailing permanent lining, dry vibrating mix working lining, spray coating layer, and impact zone gunning repair.
Technical Data Sheets (TDS)
Indicative industry reference ranges for each material family — confirm exact figures against the mill test certificate/COA for your specific order, and request our full TDS for the grade matched to your mix design.
Tundish Dry Vibrating Mix (Magnesia-Based)
| Property | Typical Value |
|---|---|
| MgO | ≥ 75% |
| SiO₂ | ≤ 10% |
| Bulk Density (110°C dried) | ≥ 2.80 g/cm³ |
| Apparent Porosity | ≤ 22% |
| Cold Crushing Strength (110°C × 24h) | ≥ 6 MPa |
| Cold Crushing Strength (1500°C × 3h) | ≥ 12 MPa |
| In-Service Sintering Face Temperature | ~1550–1600°C |
| Maximum Service Temperature | 1700°C |
| Typical Working Face Thickness | 20–40mm sintered + 15–25mm unsintered buffer |
Tundish Spray Coating Mix (Alumina / Magnesia-Based, Wet Spray)
| Property | Typical Value |
|---|---|
| Al₂O₃ (or MgO for Mg-based grade) | ≥ 60% (MgO grade: ≥ 65%) |
| Bulk Density | ≥ 2.60 g/cm³ |
| Cold Crushing Strength (110°C) | ≥ 20 MPa |
| Cold Crushing Strength (1000°C) | ≥ 35 MPa |
| Apparent Porosity (1000°C) | ≤ 24% |
| Application Thickness | 10–20mm |
| Setting Time | 20–40 minutes |
| Thermal Shock / Adhesion (3 cycles) | No spalling |
| Maximum Service Temperature | 1650°C |
Tundish Gunning / Patching Mix
| Property | Typical Value |
|---|---|
| MgO (or Al₂O₃ for alumina-based grade) | ≥ 70% |
| Bulk Density (cured) | ≥ 2.70 g/cm³ |
| Cold Crushing Strength (110°C) | ≥ 10 MPa |
| Setting Time | 5–15 minutes |
| Adhesion to Existing Lining | Pass — no detachment on thermal cycle |
| Rebound Loss | ≤ 15% |
| Maximum Service Temperature | 1700°C |
Reading Tundish Lining Wear — What the Pattern Tells You
Even Wear Across the Sidewalls
Normal consumption of the dry vibrating mix or spray coating working face. If this is progressing faster than your campaign plan assumes, the first thing to check is MgO grade match to your steel chemistry, not simply switching to a thicker lining.
Deep Localized Wear at the Impact Pad
This is the signature of impact erosion, not general chemical attack, and it's the case gunning mix exists for — a local hot repair restores the pad without disturbing a sidewall lining that still has service life left.
Surface Crazing or Spalling After Few Heats
Points to a thermal expansion mismatch or an installation/curing issue rather than a material-grade problem — this is exactly the failure mode our on-site engineers are positioned to diagnose during installation support rather than after the fact.
What a Procurement Spec Should Include
Plant Operating Parameters & Factory Verification Checklist
Key Sieve & Chemical Specifications:
Standard Verification Points:
- Tundish capacity and geometry (straight, delta, T-shape)
- Steel grades cast and any grade-specific cleanliness requirements
- Average and maximum sequence length (heats per campaign)
- Current lining material, thickness, and typical wear pattern/location
- Installation method available (vibration access, spray equipment, gunning machine)
- Whether impact pad is currently a separate material or part of the main lining
- Required TDS confirmation format (COA per batch, per lot, or per shipment)
Frequently Asked Questions (FAQ)
Can dry vibrating mix and spray coating be used in the same tundish?
Yes — spray coating is commonly used for localized areas or as a fast-turnaround option on vessels that alternate between long and short sequences, while dry vibrating mix remains the primary lining. We can specify both as part of one lining system.
How does tundish working lining quality affect metering nozzle and stopper rod control downstream?
A poor-quality or improperly cured dry vibrating mix erodes under turbulent molten steel, releasing loose magnesia aggregates and silicate glassy phases directly into the bath. When drawn toward the tundish floor, these exogenous particles accelerate alumina agglomeration inside nozzle orifices and disrupt stopper tip seating. Pairing a high-density, slag-resistant dry vibrating mix with our monolithic stopper rods and zirconia-core anti-clogging nozzles eliminates refractory wash-in and keeps flow diameters consistent across extended sequences.
How many heats should a tundish dry vibrating mix lining last?
This depends heavily on steel grade, sequence length, and impact pad protection strategy — send us your working data and we'll give you a realistic campaign-life estimate based on comparable installations, not a generic number.
Does gunning mix replace the need for a full reline?
No — gunning mix extends a campaign by repairing local wear between full relines. It is a maintenance tool, not a substitute for correctly timed full lining replacement.
What causes a gunned repair to fall off after a few heats?
Almost always an adhesion failure at the bond to the existing worn lining, usually from surface prep or application temperature, not a defect in the gunning material itself — this is a core focus area for our on-site installation support.
Can you match an existing lining chemistry we're already running?
Yes — send us your current TDS or COA and we can benchmark a matched or improved-performance alternative for trial.
Do you supply the impact pad material separately from the main working lining?
Yes — many of our customers run a standard dry vibrating mix body with a higher-wear-resistance gunning mix reserved specifically for impact pad maintenance.
Related Solutions & Engineering Pages
- Stopper Rod, SEN & Ladle Shroud — Continuous casting flow control train featuring isostatic ZrO₂ stopper tips, slag-line reinforced SENs, and argon-sealed ladle shrouds.
- Tundish Nozzle Manufacturer — Zirconia-Core Anti-Clogging Bore
- Tundish Refractory Solutions — Working Lining & Flow Control Packages
- Tundish Impact Pad & Turbulence Inhibitor Manufacturer — Energy Dissipation
- Tundish Weir Wall & Dam Block Supplier — Corundum Flow Control Refractories
- Tundish Cover Castable Supplier — Pour-Box Collar & Seal Rim Refractory
- Tundish Nozzle Seat Brick (Well Block) Manufacturer
- Ladle Well Block — Nozzle Well Refractory for Ladle Casting
- RH Snorkel — Up-Leg and Down-Leg Immersion Tube for RH Vacuum Degassing
- Copper Mould Tube — Continuous Casting Mould Assembly
- China Magnesia Market Report — Price Trends and Policy Outlook
Request a Tundish Refractory Mix Design & Trial Samples
Send us your tundish working data — capacity, steel grades, sequence length, current lining performance — and our technical engineers will propose a free mix design, arrange free samples for trial, and schedule on-site installation support where needed.
Direct Engineering Email: sales@ykchanshine.com | Plant Line: +86-139-9807-2158