Furnace Mouth Castable

Description

JH-CAST 70 is a low‑cement mullite‑corundum castable developed for use as both the refractory lining of coreless induction furnace covers and as pouring rings for the furnace mouth, furnace bottom and bottom push‑out blocks. The castable combines a high‑alumina matrix with controlled SiO2 and low CaO to deliver good thermal insulation, high strength and a long service life under the severe thermal cycling typical of induction melting.

The product supports three installation techniques—vibration, pouring and self‑flow—each with defined water addition to achieve optimal flow and set times. Vibration casting uses 4.75 % water with a working time of about 40 min and initial set in 2–6 h, while pouring requires 5.5 % water, a 50 min working window and set times of 12–24 h. Self‑flow mixing adds 6.3 % water, extends working time beyond 60 min and reaches final set between 16–24 h. Optional addition of 4 % stainless‑steel fibre enhances low‑temperature strength and improves resistance to thermal shock, making JH‑CAST 70 a versatile choice for prefabricated furnace components and on‑site repairs of vacuum and medium‑frequency induction furnaces.

Key Features

1. Low-cement mullite-corundum matrix provides high strength and thermal stability for demanding induction furnace environments.
2. Three installation methods—vibration, pouring, and self‑flow—allow flexible application with water addition ranging from 4.75% to 6.3%.
3. Wide water‑addition tolerance preserves physical properties across all mixing ratios, simplifying on‑site adjustments.
4. Excellent abrasion resistance extends service life under high‑speed molten metal flow and mechanical stress.
5. Optional 4% stainless‑steel fibre addition enhances low‑temperature strength and thermal shock resistance.

Application

• Prefabricated furnace‑cover components for coreless induction furnace linings, providing reliable high‑temperature protection.
• Furnace‑mouth and collar pouring rings formed by vibration, pouring, or self‑flow methods to seal the hearth area.
• Furnace‑bottom pouring rings and bottom push‑out blocks cast on‑site to reinforce structural integrity at the base.
• On‑site pouring and repair of vacuum induction furnace linings, accommodating medium‑frequency units with consistent performance.
• Suitable for maintenance of both coreless and medium‑frequency induction furnaces, extending campaign life and reducing downtime.

Technical Specifications

JH-CAST 70 supports three installation methods (vibration, pouring and self-flow) with distinct water addition and setting time; the tables below list chemistry, physical properties and operating parameters.

Operating Parameters by Installation Method