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SUMMARY OF IDEA OR CONCEPT
One of our Thin Slab customers requested Vesuvius’ assistance in preventing what he called “Bubble Lams” – a situation at multiple Thin Slab (and likely all thin and medium slab shops) where buildup on the SEN is spalling or flaking-off during casting. This occurs below the meniscus (likely from both the inside and outside SEN surfaces). It is believed that this buildup detaches during casting and consolidates in the product only to be found when rolling to final thickness at the customer of our customer. Based on pareto analysis of the end user of our customer’s complaints, the results showed that rolled non-metallic inclusions were number one or two on the final customers list claims or complaints.
The caster manager at the Alpha site asked us to focus our efforts on helping them reduce this defect from occurring by providing a cleaner refractory that does not promote as much buildup. He asked for a completely reaction-free refractory in his steel. He also indicated that if Vesuvius did not want to work on this, he would work with other refractory suppliers. A nonreactive refractory was not feasible, but we took the approach of a much less reactive material.
-- Mike Tindale
Development History
- TS1239: low-degassing mix for AccuOptix. This was the first mix tested as a liner, and suffered thermal shock, but produced a cleaner bore than the standard 238. No current users.
- TS1243: cold-start version of high-purity TS291. This mix was tried as a liner and showed similar cleanliness to TS1239, but without thermal issues. These results created a lot of excitement in the Alpha group
- TS1285: modified TS291 with improved thermal shock resistance (291-P) was developed to become the standard mix for the Clean Steel Liner. This mix has the benefit of high purity (which reduces reaction) and thermal shock resistance to prevent thermal shock.
Status
Other Benefits
- TS1285 hot MOR is greater than that for TS238 (TS1243 is in a similar range as TS1285)
- TS1285 cold MOR is much lower than TS238
- Higher hot MOR combined with reduced penetration would indicate that 1285 would better resist narrow face breakage during the cast
- TS1285/TS1243 thermal shock resistance is greater than TS238
Thermite results of 100% vs. only 70% for TS238
Clean Steel Liner Technology - 1285
The piece has std body mix and shows the typical inclusion attachment on the surface.
The piece has the 1285 Clean Steel Liner and shows an improved surface quality translating to lower risk of detachment during casting. This results in lower risk of steel defects
Clean Steel Liner Technology - 1285 reduced worn-holes and buildup
Std Mix
TS1285