Keystone Steel & Wire Co. |
Cleaner Steel Practices and Benefits
The completion of an $80 million investment in our steel making facility has enabled Keystone to implement practices that produce dramatically cleaner steel and significantly improved wire rod quality for our customers.
These improvements include:
- An Eccentric Bottom Tapping (EBT) furnace for melting and refining ferrous scrap. As the molten steel is tapped into the ladle, it drains from the furnace through a bottom tap hole. This avoids slag carryover present in other furnace designs, reducing contamination from melting furnace slag.
- A Ladle Metallurgy Furnace (LMF) for accurate temperature, chemistry and cleanliness control. A "white slag" refining practice at the LMF deoxidizes, desulfurizes and absorbs non-metallic inclusions from the steel. Temperature, chemistry and oxygen levels are checked and adjusted to meet strict specifications. During this process the steel is "bottom stirred" with argon gas through a porous plug to improve the homogeneity of the steel before the ladle is moved to the continuous caster.
- A Six-Strand Continuous Billet Caster for production of excellent quality billets. At the caster the ladle is placed above the tundish, which receives the molten steel. As the steel moves from ladle to tundish it is shrouded from atmospheric contamination. The large tundish (30-ton capacity) and special dams allow non-metallic inclusions to float out of the steel and into the slag layer. Nitrogen-purged shrouds completely enclose the steel stream from the tundish to mold to prevent oxygen in the atmosphere from forming new non-metallic inclusions.
The cleaner steelmaking practices described in this bulletin provide a number of quality and productivity benefits for Keystone's wire rod customers:
- Improved drawability of the rod, meaning faster drawing speeds, greater draft reduction without breakage, and improved die life. Keystone's own wire drawing facilities have documented significant productivity gains using the new cleaner steel rods.
- Improved surface quality, leading to better cosmetic surfaces in plating applications, fewer and shallower seams, and a reduction in slivers in the rod.
- Improved internal quality, providing better heading or cold forming, better cross wire and butt welding performance, and improved bending and forming performance.
Hot rolled carbon steel wire rod. Chemistries from C1005B to C1038. Size range from .219" (5.5mm) to .500" (12.7mm). Coil size: 4,100 pounds (1,860 kg), compacted and wire tied.