Short answer

A slag pot's entire load — often tens of tons of molten slag — is carried by two small trunnions. Tenfaye forges each trunnion separately first, compacting the steel's internal grain structure, then places the forged trunnion into the mold and casts the pot body around it in a single pour. The result is a slag pot with no weld seam between trunnion and body — the single weakest point on a conventional slag pot — which significantly extends service life.

1. The Trunnion Is the Real Load-Bearing Point

A slag pot itself is a large container, but almost all of its structural stress concentrates in two places: the trunnions. These short shafts support the full weight of the pot and its molten contents while the crane rotates and tips it. Every lift, every tilt, every thermal cycle passes directly through this small section of steel.

When a trunnion fails, the pot doesn't just wear out — it becomes a safety hazard on the shop floor.

2. Why Welded Trunnions Fail First

Most conventional slag pots are cast in two pieces: the body is cast, the trunnion is cast or forged separately, and the two are joined by welding.

This creates three recurring problems:

1.Weld seam as a stress riser — the joint between trunnion and pot wall becomes the first place fatigue cracks start.
2.Heat-affected zone (HAZ) weakness — welding locally alters the steel's grain structure, leaving a zone that is mechanically weaker than the surrounding cast steel.
3.Repeated thermal shock — molten slag pouring in and out subjects the weld to constant expansion and contraction, accelerating crack growth at the seam.

In field use, it is almost always the weld area — not the pot body — that fails first.

3. Tenfaye's Forge-First, Cast-Together Process

Tenfaye addresses this at the design stage rather than trying to reinforce the weld afterward.

1.Forge the trunnion independently. The trunnion is forged as its own component. Forging compresses and densifies the internal grain structure, closing internal porosity and aligning the metal's flow lines along the axis that will carry the load.
2.Position the forged trunnion inside the mold cavity. Before pouring, the pre-forged trunnion is set precisely into the mold for the pot body.
3.Cast the entire pot in one pour. Molten steel is poured around the forged trunnion, fusing trunnion and body into a single, continuous casting — with no weld line at all.

Because the trunnion and body solidify as one piece, there is no HAZ, no seam, and no separate joint to fail.

4. What This Means for Service Life

1.No weld seam means no seam-initiated cracking — the historically weakest point is designed out of the part entirely.
2.A forged trunnion carries higher fatigue strength than a cast-only trunnion, since forging closes internal voids that would otherwise seed cracks under repeated loading.
3.Fewer unplanned pot replacements, which translates directly into less production downtime for mills, kilns, and slag-handling lines.
4.Lower total cost of ownership, even where the upfront casting cost is comparable to a welded design, because service life extends well beyond a standard welded pot.

5. Where This Matters Most

This kind of integral, weldless trunnion casting is most valuable for:

1.Mining and mineral processing plants, where slag pots run continuous, heavy-duty cycles.
2.Cement plants, where rotary kiln auxiliary equipment faces similar cyclic thermal and mechanical loads.
3.Equipment manufacturers and EPC contractors, who need casting partners capable of engineering load-bearing components rather than simply pouring steel to a drawing.

In Summary

Slag pot failures rarely start in the body — they start at the trunnion weld. By forging the trunnion first and casting it into the pot body as one continuous piece, Tenfaye removes that weak point at the source, producing a slag pot engineered for a longer, more predictable service life.

For mills, kilns, and mining or cement equipment producers evaluating slag pot design or replacement cycles, Tenfaye welcomes technical discussion on custom trunnion specifications and engineering collaboration — from load calculation through final casting.