📋 Case Study

Boom Section Replacement on Large-Capacity Self-Propelled Sprayer

Hybrid material interface (HSLA-100 + CFRP adhesive bond); no existing WPS for dissimilar joining

🏗️ Project Overview

Structural failure of carbon-fiber reinforced steel boom section on Case IH 4000 Series sprayer

🎯 Challenge

Hybrid material interface (HSLA-100 + CFRP adhesive bond); no existing WPS for dissimilar joining

🔧 Design Approach

Mechanical fastening + localized GMAW overlay with Ni-based filler (ERNiCrMo-4); PQR developed using ASTM E2921 test coupons simulating thermal gradient

📐 Design Diagram

AI-generated project design illustration

📐 Key Calculations

Thermal Gradient Ratio

ΔT / thickness

Result: 125°C/mm

Guides filler selection to avoid liquation cracking

Adhesive Bond Temperature Limit

Tg − 20°C

Result: 130°C

Dictates maximum interpass temperature

📊 Results

100% UT acceptance; 92% fatigue life retention vs. original; approved for fleet-wide deployment

💡 Lessons Learned

• •Adhesive thermal limits govern interpass control more than base metal
• •Ni-based fillers reduce residual stress at hybrid interfaces

✅ Key Takeaways

• 1Adhesive thermal limits govern interpass control more than base metal
• 2Ni-based fillers reduce residual stress at hybrid interfaces