Sinter Machine Grate Bar Castings for Iron Ore Sintering

The grate bars sit on the sinter machine pallets and form the permeable bed the hot sinter mix rides on as it travels and ignites. They run hot, oxidize, and see repeated thermal cycling while abrasive sinter scrapes past. Tiegu supplies sinter machine grate bars to iron ore sintering plants worldwide, matching each order to a foundry that runs heat-resistant cast steel and checks the bar profile and hole pattern against your drawing before export.

1. What Grate Bars Do

The bars hold the sinter bed and let air pull down through it during ignition and cooling. They must stay straight and keep their gap so the bed breathes evenly; a warped or clogged bar starves a section of air and drops sinter quality, while a broken bar drops material through the pallet. Grate bars are consumable spares planned on thermal-cycle life, not unit price.

For a broader view of how we handle sourcing wear-resistant castings from China, see our casting sourcing guide.

2. Why Material Grade Decides Service Life

A grate bar lives or dies by heat resistance and thermal-fatigue cracking, so the grade is chosen by sintering temperature and atmosphere:

• ZG40Cr25Ni20 / ZG35Cr28Ni16 heat-resistant cast steel — high Cr and Ni hold strength and resist scaling at sintering temperature; the workhorse for hot-zone bars.

• Medium-silicon heat-resistant ductile iron (SiMo) — a lower-cost option for the cooler, less aggressive zones where the duty is less severe.

• High-chrome cast iron (selected zones) — where abrasion from the sinter outweighs the thermal load; used with care because of brittleness.

Pick the grade by zone temperature and gas atmosphere, not by habit. If you are unsure how to choose a casting supplier that runs these grades, the supplier-selection guide walks through the foundry checks that matter.

3. What We Verify Before Shipment

Grate bars are bought on heat resistance and fit, not on a nameplate. For these orders, Tiegu confirms the following with the foundry and on the documents:

• Chemistry on the MTC: verify Cr, Ni, and Si against the ordered grade — these set the high-temperature strength and oxidation resistance that decide service life. See our note on how to read a mill test certificate.

• High-temperature behavior: confirm the rated service temperature and check the as-cast microstructure for soundness; for critical bars we review oxidation and thermal-fatigue resistance with the foundry.

• Profile and hole pattern: dimensionally inspect the bar contour, ventilation slot or gap, and pallet hook dimensions against your drawing — a mismatched bar changes the air gap and the whole bed suffers.

• Row interchangeability: for pallet-mounted rows, confirm replacement bars match the set in service so a partial change-out keeps the bed even.

Not sure which heat-resistant grade fits your sinter zone? Contact us at tieguexport.com →

4. Specification Checklist for Buyers

• Sinter machine type and pallet width, and the bar position (hot / cool zone).

• Grade (ZG40Cr25Ni20, SiMo ductile, etc.) and rated service temperature.

• Drawing with contour, slot or gap, hook dimensions, and tolerance (ISO 8062).

• Required NDT and surface condition.

• Spare quantity and lead time — bars wear on a thermal cycle, so confirm before a planned pallet overhaul.

When you are ready, submit an RFQ with your drawing and we will confirm grade, foundry match, and inspection scope.

FAQ

1. Which heat-resistant grade should I specify for grate bars?

It depends on the zone temperature and atmosphere. High Cr-Ni steel suits the hot zone where scaling and thermal fatigue dominate; SiMo ductile iron works in cooler zones at lower cost. We confirm the grade against your sinter duty rather than defaulting to one.

2. How long does a grate bar last?

It is governed by thermal cycling and sinter abrasiveness, counted in pallet passes rather than months. Operators plan bar changes on a pallet overhaul; we help confirm grade and lead time so spares are ready.

3. Do you supply single bars or full pallet rows?

Tiegu supplies cast grate bars to drawing, single or as a matched row. For assembled pallet sets we confirm the scope with you and arrange the foundry and inspection accordingly under one contract.

Tiegu is a China-based casting supplier serving international buyers through a vetted network of qualified Chinese foundries. We supply castings under a single commercial contract, managing supplier selection, technical confirmation, quality inspection, and export delivery from order to shipment.

Request a quote for sinter grate bar castings →