In industrial production lines for conveying, mixing, crushing, and extruding, the screw flight (Screw Flight / Screw Blade) is one of the most wear-prone and performance-critical components. It directly engages in material conveying and shearing and is constantly exposed to sand, fibers, chemical granules, or corrosive media. After long-term operation, wear, deformation, or even breakage becomes inevitable.
Directly replacing worn screw flights is expensive and often leads to extended downtime. Therefore, using PTA (Plasma Transferred Arc) welding for screw flight restoration and surface hardening has become a cost-effective and high-performance solution.
Common Problems of Screw Flights
Different working conditions lead to different wear modes, but most problems fall into four categories:
1. Abrasive Wear – Thinning Blades & Reduced Efficiency
Hard particles such as sand, mineral powder, glass fiber, and metal fragments continuously grind the flight surface, causing:
- Progressive thinning
- Reduced conveying capacity
- Increased energy consumption
This is one of the most frequently reported issues.
2. Impact Wear – Chipping, Cracks, Damaged Edges
Blocky materials or metal impurities may repeatedly strike the flight edges, leading to:
- Local spalling
- Edge deterioration
- Surface cracking
- Severe cases can affect downstream equipment.
3. Corrosion & High-Temperature Wear – Particularly in Chemical and Sludge Applications
Acidic or alkaline materials corrode the flight surface, and high temperatures accelerate annealing, resulting in:
- Reduced hardness
- Particle detachment
- Shortened service life in harsh environments
4. Blade Deformation – Poor Precision & Process Instability
Uneven loads or overloading may cause the screw flight to:
- Twist or warp
- Become eccentric
- Develop uneven clearances
- This directly affects conveying performance and increases vibration.
Why Choose PTA Welding for Screw Flight Restoration?
PTA welding is not only a repair method—it is a performance upgrade. Compared with conventional welding or coating, PTA offers substantial advantages.
Metallurgical Bonding — Stronger Than Surface Coatings
Molten alloy powder fuses directly with the base metal, delivering superior bonding strength and excellent resistance to impact and peeling.
Multiple High-Wear-Resistant Alloy Options
Suitable alloy powders include:
• Ni-based alloys – Tough, all-purpose wear resistance
• Co-based alloys – Best for high-temperature, high-impact environments
• WC/Ni composite powders – Extend lifespan by 3–10× under severe abrasion
• Powders can be customized for your process materials.
Uniform Weld Layers with Minimal Distortion
PTA produces clean, consistent weld beads with minimal deformation—ideal for maintaining flight geometry accuracy.
Repair + Reinforcement = Longer Life Than New
Besides restoring dimensions, PTA adds a superior wear-resistant layer, exceeding the durability of many new flights.
Complete PTA Restoration Process for Screw Flights
1. Failure Inspection & Evaluation
Thickness checks, geometric measurements, and metallographic analysis determine wear severity and define the repair plan.
2. Cleaning & Pre-Treatment
- Rust removal
- Grinding of corrosion pits
- Straightening of deformed areas
- Surface preparation for optimal bonding
Robotic systems follow the helical path while precisely controlling:
- Current
- Powder feeding
- Overlap rate
- Shielding gas
Depending on wear depth, each helix typically receives 1–3 layers.
4. Final Machining & Finishing
- Precision machining to restore original dimensions
- Edge grinding
- Polishing for smoother material flow
The final accuracy meets or exceeds new-part standards.
Industries That Benefit from PTA Screw Flight Restoration
PTA restoration is ideal for high-wear screw-driven equipment, including:
- Plastic extrusion and compounding machinery
- Rubber and chemical conveying screws
- Biomass processing flights
- Mining, crushing, and powder transport systems
- Feed mixing and processing equipment
- Sludge dewatering and environmental equipment
Wherever abrasion, impact, or corrosion is present, PTA significantly extends service life.
Cost Advantages: Restoration vs. Replacement
Users who adopt PTA repair typically report:
• Only 1/3 to 1/2 the cost of new screw flights
• Short turnaround—often within a few days
• Greatly extended lifespan
• Reduced downtime
• Lower total operating costs
This is why PTA has become a preferred solution for screw flight maintenance.
Customized PTA Restoration & Hardening Solutions
As a professional PTA surface engineering service provider, Shanghai Duomu Industrial offers:
Complete PTA restoration for screw flights
- Custom alloy powder formulations optimized for different working conditions
- Precision, stable automated PTA welding processes
- Wear analysis and lifecycle improvement consulting
- Mass-production capability for long-term industrial maintenance needs
We understand your requirements for stability, durability, cost efficiency, and fast delivery.
Our goal is to provide not just repairs, but a comprehensive solution that enhances equipment efficiency, minimizes downtime, and extends operational life.
Post time: Nov-27-2025