Cutting Rework and Rejection at a Tractor-OEM Captive Foundry with Lustron HPL

Goal

Bring Sand Fusion and Metal Penetration Under Control Across a 72,000 MTPA Facility

The foundry, which supplies castings to ITL( the third-largest tractor manufacturer in India and a leading exporter) operates Rhino and KW molding lines producing GB housings, front axle brackets, trumpet housings, crank cases (3-bore and 4-bore), and differential housings. Capacity had been revised upward from 28,800 to 72,000 MTPA. The goal was to reduce sand fusion, metal penetration, and shot-blasting time without disturbing this expanded production base.

Challenge

• Sand fusion and metal penetration affecting up to 50% of castings
• Sand peel-off and collapsibility issues
• Excessive shot blasting time
• Increased overall cycle times and operational costs

Outcome

Lustron HPL was introduced in phases — 50% Lustron HPL with 50% existing Lustrous Carbon Additive (LCA) on days 1–2, 75% Lustron HPL on days 3–4, and 100% Lustron HPL from day 5 onward. Specified to VM 50±5%, Ash ≤6%, and 80% minimum passing at 0.212mm.

Improvements were evident within 18–24 hours, with no changes made to bentonite source, carbonaceous additive quality, sand source, water source, or inert fines levels (max 3.50%):

• Foundry-stage rejection reduced from the 8.2% range to 5–6%, a 32.92% reduction
• Shot blasting time reduced from 15 minutes to 9 minutes, a 40% reduction
• Casting rework reduced from 50% to 5%, a 90% reduction
• Significant improvement in casting surface finish
• Faster casting turnaround and improved productivity
• Lower shot consumption, reducing electricity usage and improving energy efficiency
• ₹18 lakh in savings generated across 529 MT of output