CLADDING TECHNOLOGY SHANXI CO., LTDManufacturing of Wear-Resistant Composite Steel Plates Using Powder-Filled Weld Overlay Method
Literature Overview
This 2001 publication from Beijing University of Technology, in collaboration with the Chinese Academy of Agricultural Mechanization Sciences and Tangshan Cement Machinery Factory, describes the development of wear-resistant composite steel plates manufactured using a powder-filled weld overlay technique. Published in "Mechanical Engineering Materials," this work represents an early Chinese contribution to the field of engineered wear plates and demonstrates the practical application of advanced overlay technology in heavy equipment manufacturing.
Core Technical Content and Analysis
The powder-filled weld overlay method combines the advantages of arc welding (good penetration, high deposition rate) with the compositional control of powder metallurgy. Unlike conventional solid wire overlay, the powder-filled process introduces additional alloying elements through a powdered flux core, enabling the creation of complex multi-phase microstructures in the overlay deposit.
Process Configuration and Parameters
| Process Element | Specification | Purpose |
|---|---|---|
| Base plate | Q235/Q345 carbon steel, 16–40 mm thick | Structural support |
| Overlay wire | Flux-cored or solid wire with powder addition | Wear layer deposition |
| Powder composition | Cr-C-B-Ni system or Fe-Cr-C-Ni system | Hard phase formation |
| Shielding gas | Ar or Ar+CO2 (80/20) | Atmosphere protection |
| Welding current | 250–400 A (SAW) | Adequate heat input |
| Travel speed | 100–200 mm/min | Bead overlap control |
| Bead overlap | 50–70% | Uniform thickness |
| Overlay thickness | 3–6 mm | Wear life optimization |
| Number of passes | 2–4 | Dilution reduction |
Microstructural Design Philosophy
The composite plate design follows a layered approach where the base steel provides structural strength and the overlay layer provides surface wear resistance. The powder-filled method enables the creation of a gradient microstructure in the overlay layer:
- Surface layer: Rich in hard carbide phases (Cr7C3, Cr3C2, Fe3C) with hardness of 60–80 HRC
- Transition layer: Mixed carbide and martensitic matrix with hardness of 45–60 HRC
- Bond layer: Diluted overlay with good metallurgical bonding to base steel, hardness of 25–40 HRC
This gradient structure provides excellent crack arrest capability, as any crack initiating at the hard surface must traverse progressively tougher material before reaching the base plate.
Manufacturing Process Flow
- Base plate preparation: Flattening, cleaning, and preheating to 200°C
- Bond layer deposition: Low-alloy consumable with controlled dilution
- Transition layer deposition: Medium-alloy powder-filled wire
- Surface layer deposition: High-alloy powder-filled consumable
- Surface finishing: Grinding to specified thickness and flatness
- Post-weld heat treatment: Stress relief at 550–650°C for 2–4 hours
- Quality inspection: Hardness mapping, thickness measurement, NDT
Quality Control and Defect Prevention
The manufacturing of composite wear plates using powder-filled overlay presents several quality challenges that require systematic control:
| Defect Type | Root Cause | Prevention Measure |
|---|---|---|
| Cracking at bond line | High carbon content, rapid cooling | Preheat to 200°C, low interpass temperature |
| Porosity | Powder moisture, inadequate shielding | Powder drying at 200°C for 2h, adequate gas flow |
| Uneven thickness | Travel speed variation, bead overlap inconsistency | Automated welding, consistent overlap |
| Excessive dilution | High heat input, first pass on steel | Multi-pass strategy, controlled first pass parameters |
| Surface segregation | Powder distribution non-uniformity | Powder mixing verification, feeder calibration |
Performance Characteristics
Typical performance data for powder-filled overlay composite plates include:
- Overlay hardness: 58–75 HRC (depending on powder composition)
- Bond strength: >300 MPa (tensile test per ASTM A263)
- Impact resistance: 20–50 J at -40°C (Charpy V-notch)
- Abrasive wear life: 3–5 times that of hardened steel (ASTM G65 test)
- Service temperature: Up to 400°C without significant property degradation
Engineering Applications and Case Studies
The composite plates developed in this research found application in:
- Cement industry: Mill liners, chutes, and wear plates in grinding circuits where abrasive wear from clinker particles is severe
- Agricultural machinery: Plow shares, augers, and conveyor components subject to soil abrasion
- Mining equipment: Bucket teeth, crusher liners, and conveyor chutes
The collaboration with Tangshan Cement Machinery Factory provided real-world validation of the technology, with reported service life improvements of 3–5 times compared to conventional hardened steel components in cement grinding applications.
Study Insights and Reference Value
This publication is historically significant as one of the earlier Chinese contributions to powder-filled overlay technology for composite wear plate manufacturing. The systematic approach to process development — from laboratory qualification through pilot production to industrial validation — provides a model for technology transfer in the Chinese heavy industry sector. For contemporary engineers, the study's emphasis on multi-pass gradient overlay design remains relevant, as it addresses the fundamental challenge of combining hardness with toughness in surface engineering applications. The methodology described can be adapted to modern automated welding systems with improved powder feeding control and real-time parameter monitoring, offering enhanced consistency and reduced manufacturing variability.