Composite Boron Nitride Ceramic Lance Tip for Molten Steel Immersion

Boron Nitride Ceramic Lance Tip

What Is a Lance Tip?

In steelmaking, a lance tip is the terminal component installed at the end of an immersion tube. It delivers gases, injects powders, or performs sampling and measurement while being directly exposed to molten steel or molten slag. The assembly further comprises a shroud that longitudinally encases the composite tube and is injectable with an inert gas to mitigate fluid contamination of the composite tube and the immersed melt surface.

Depending on the process, a lance tip may be used for:

Molten steel temperature measurement
Oxygen or inert gas injection
Alloy powder injection
Steel refining
Degassing processes
Continuous casting operations

Because the tip is the only part directly immersed in molten metal, it experiences one of the harshest environments found in steel plants.
Typical operating conditions include:

Temperatures above 1,600°C
Thermal shock during repeated immersion
Chemical attack from molten steel and slag
Mechanical erosion caused by metal flow
Oxidizing or reducing atmospheres

These extreme conditions make material selection one of the most important design considerations. Therefore, Innovacera recommends Composite Boron Nitride for this application, which has been validated by customers and has received excellent feedback.

Why Choose Composite Boron Nitride (BMZ) Ceramics for Lance Tips?

Composite Boron Nitride (BMZ) ceramics have become the material of choice for components in immersion tubes. Their superior performance stems from the combination of boron nitride’s excellent non-wetting properties and the enhanced mechanical strength provided by zirconia.

Key advantages include:

1. Excellent Resistance to Molten Steel Wetting

BMZ exhibits extremely low wettability regarding molten steel and slag. This minimizes metal adhesion, helping to maintain precise gas flow rates and reducing the need for cleaning.

2. Outstanding Thermal Shock Resistance

Lance tips are frequently subjected to rapid temperature fluctuations between room temperature and the temperature of molten steel. BMZ can withstand repeated thermal cycling with a very low risk of cracking.

3. High-Temperature Stability

BMZ maintains dimensional stability even when continuously exposed to steelmaking temperatures. This ensures consistent performance across multiple immersion cycles.

4. Ease of Precision Machining

BMZ can be machined into complex geometries with high precision.

5. Long Service Life
By resisting thermal shock, chemical erosion, and molten metal adhesion, BMZ lance tips typically offer a longer service life than traditional ceramic materials. A longer service life translates to:

Less frequent replacement
Reduced maintenance requirements
Lower operating costs
Higher production efficiency