ToolFusion
📋 Case Study

Case Study: Electrochemical Corrosion in Case IH Axial-Flow Combine Header Wiring

Rapid aluminum wiring harness degradation at steel frame attachment points after 3 seasons

🏗️ Project Overview

Fleet-wide header retrofit program integrating yield mapping sensors and hydraulic auto-adjust systems

🎯 Challenge

Rapid aluminum wiring harness degradation at steel frame attachment points after 3 seasons

🔧 Design Approach

Replaced direct aluminum-to-steel lugs with bimetallic transition washers (copper-plated stainless), applied dielectric grease to all ground interfaces, introduced insulated ground bus bar with dedicated 6 AWG copper jumpers

📐 Design Diagram

Al WiringΔE = 0.72 VSteel FrameJ = 0.04 A/cm²Cu-SS Washer(bimetallic)Dielectric GreaseInsulated Bus Bar6 AWG Cu JumperCorrosion Mitigation DesignCase IH Axial-Flow Header • Electrochemical Corrosion Control

AI-generated project design illustration

📐 Key Calculations

Galvanic Series Potential Difference

ΔE = |E°(Al) − E°(Fe)|
Result: 0.72 V
High corrosion risk threshold exceeded

Current Density Limit

J ≤ 0.1 A/cm² for Al-steel junctions
Result: 0.04 A/cm² achieved
Safe long-term operation

📊 Results

Zero corrosion failures over 5-year warranty period; 100% retention of sensor calibration accuracy; elimination of seasonal harness replacement cycle

💡 Lessons Learned

  • •Material pairing dominates corrosion rate more than environmental exposure
  • •Dielectric barrier integrity is as critical as electrical continuity
  • •Ground bus bars reduce localized current crowding at junctions

✅ Key Takeaways

  • 1Material pairing dominates corrosion rate more than environmental exposure
  • 2Dielectric barrier integrity is as critical as electrical continuity
  • 3Ground bus bars reduce localized current crowding at junctions