📋 Case Study

Loader Arm Fracture Repair in Sub-Zero Conditions

No shop access; extreme cold causing hydrogen cracking risk and brittle behavior

🏗️ Project Overview

Hydraulic loader arm fracture on New Holland TL80 at -28°C northern Canada site

🎯 Challenge

No shop access; extreme cold causing hydrogen cracking risk and brittle behavior

🔧 Design Approach

Induction preheat to 120°C + low-hydrogen SMAW (E7018-H4R); portable tent enclosure with forced-air heating; real-time IR thermography monitoring

📐 Design Diagram

120°CIR Thermography
Real-timeTent Enclosure
Forced-air heatingHydrogen Diffusion
t = (d²×10⁴)/D = 18.4 hToughness ≥47 J @ -40°C
(ASTM A6/A6M → 52 J)

AI-generated project design illustration

📐 Key Calculations

Hydrogen Diffusion Time

t = (d² × 10⁴) / D

Result: 18.4 hrs

Dictates mandatory post-heating duration to prevent delayed cracking

Minimum Toughness Requirement

≥47 J @ -40°C per ASTM A6/A6M

Result: 52 J

Validated via Charpy sub-size specimens

📊 Results

Successful field repair completed in <48 hrs; zero failures over 2 seasons; became OEM’s standard Arctic repair protocol

💡 Lessons Learned

• •IR thermography is non-negotiable for field preheat verification
• •Hydrogen diffusion time overrides schedule-driven PWHT

✅ Key Takeaways

• 1IR thermography is non-negotiable for field preheat verification
• 2Hydrogen diffusion time overrides schedule-driven PWHT