Last week, our community engaged in lively discussions around optimizing steel production processes and enhancing technical skills. Members explored the most effective elements for reducing manganese sulfide (Ms) in alloys, weighing their pros and cons. There was also a keen interest in educational resources, focusing on courses that can help improve mold level control techniques.
This Week’s Hot Topics
Which element drops Ms fastest
Members are sharing their experiences and research findings on which elements are most effective in reducing manganese sulfide levels. It’s a detailed look at practical applications in alloy production. Read more here
Courses for tuning mold level control
There’s a buzz around courses that can help fine-tune mold level control, a key skill for improving casting quality. Members are recommending programs and sharing insights on what has worked for them. Read more here
Looking forward to another week of valuable exchanges. Keep sharing your expertise and questions.
We cut MnS by shifting to very late Ca wire injection — “after final Al-kill with T[O] < 25 ppm” — which consistently flips MnS to globular CaS/aluminates and improved transverse properties; the caveat is overshooting Ca will spike nozzle clogging. If you’ve tried this, what Ca/Al ratio are you holding in the ladle?
Quick example: we’ve had good results with a small cerium mischmetal wire shot (about 0.6–0.8 kg/t) right after Al‑kill with T[O] ≤ 20 ppm, which flipped stringer MnS to globular RE sulfides and bumped transverse properties; just watch N/O or you’ll clog the nozzle. Anyone here tried RE wire on slab casters for free‑machining heats? For us this has been the most reliable tweak for “reducing manganese sulfide (Ms)” when Ca windows were tight last week.
We’ve had the best MnS reduction by pushing hot‑metal/LF desulfurization to S ≤ 0.0010 and keeping Mn/S > 40; that cuts MnS volume so a very small late Ca touch just rounds what’s left — small caveat: watch reoxidation or you’ll drift back to stringers. @f_barrett95, can you reliably hit single‑digit ppm S before casting?
We’ve cut MnS noticeably by aiming for a tiny Mg pickup (2–5 ppm) via Mg cored wire at LF about 5 minutes before cast; it pushes S into MgS/spinel and breaks up stringers. Keep it very low or you’ll fight nozzle clogging and flare, and it’s pricier per t than Ca. @Guide, have you tried sub‑5 ppm Mg on thin‑slab?
CaSi wire’s been my most reliable Ms reducer: aim Ca/S ≈1 with ‘T[O] < 25 ppm’ so S goes to CaS and Al2O3 to liquid calcium aluminates, then cast within about 10–15 min. That cleans up inclusions and helps mold level control versus nozzle-clog spikes; @lucy_wilson02, have you tried a small Ca trim right after RH when S is already <0.010?
Quick note from our melts: a tiny Zr trim via FeZr at LF after a clean Al-kill has helped — ‘aim Zr about 15–25 ppm’ with T[O] < 20 ppm so S ties into Zr-bearing nuclei and MnS doesn’t run long. Caveat: it’s touchier than Ca/Mg for nozzle stability, so we keep the hold short and bump superheat a bit. @Marta have you seen Zr beat Ca when S is already low (<0.005%)?