Large-Area Wear-Resistant Alloy Overlay Plate Cladding Technology: Domestic and International Developments

Literature Overview

This 1990 publication by Qian Qiang, Bao Xiaobing, Cui Rong, and Huang Wenzhe from the Harbin Welding Research Institute provides a comprehensive review of large-area wear-resistant alloy overlay plate cladding technologies, both domestic (Chinese) and international, along with their applications. This work represents an early systematic assessment of the state of the art in overlay cladding for wear-resistant applications at the time. The Harbin Welding Research Institute (HWRI) has long been recognized as a leading institution in Chinese welding research, and this publication reflects the accumulated expertise of decades of industrial application.

Classification of Overlay Cladding Technologies

The document categorizes the major technologies available for large-area overlay plate production:

Technology	Typical Overlay Thickness	Production Scale	Wear Resistance	Dilution Control
Submerged Arc Welding (SAW)	3-15 mm	Large plates (up to 6 m × 3 m)	Medium-High	Moderate
Electroslag Welding (ESW)	5-30 mm	Very large plates	High	Good
Strip Cladding (roll bonding)	1-5 mm	Very large plates	Depends on strip	Minimal
Flame Spraying (oxy-fuel)	0.5-3 mm	Large plates	Medium	Low
Powder Spray Cladding (FCAW)	2-10 mm	Large plates	High	Good
Laser Cladding	1-5 mm	Limited by beam size	Very High	Excellent

Key Process Technologies Reviewed

Submerged Arc Welding (SAW) Overlay

SAW remains the workhorse technology for large-area overlay plate production due to its high deposition rate (5-10 kg/h), good flux protection, and proven reliability. The key challenges include:

Dilution control: Multi-pass strategies with gradually decreasing dilution ratios (first pass 40-60%, subsequent passes 10-20%)
Surface quality: Achieving a smooth, defect-free surface requires careful flux management and travel speed optimization
Hardness uniformity: Large plates often exhibit hardness variations due to cooling rate differences between edge and center zones

Typical SAW overlay consumables include:

Cast iron type (Fe₃C, Fe₅C₂) for high hardness applications
Carbide-containing alloys (Cr₇C₃, WC, Cr₃C₂) for abrasive wear
High-chromium white iron (HCWI) for combined abrasive and impact wear

Electroslag Welding (ESW) Overlay

ESW provides superior dilution control and can achieve overlay thicknesses exceeding 20 mm in a single operation. The process is particularly suitable for:

Thick overlay requirements (reducing the number of passes)
Nickel-based and cobalt-based alloy overlays where dilution is critical
Very large plate dimensions where SAW would require excessive time

The ESW overlay process parameters typically include:

Current: 600-1200 A (DC)
Voltage: 30-45 V
Travel speed: 200-400 mm/min
Flux composition: Customized for each overlay material

Strip Cladding (Roll Bonding)

Roll-bonded cladding plates represent a distinct technology category where a wear-resistant strip is metallurgically bonded to a structural steel substrate through hot or cold rolling. This method offers:

Virtually zero dilution (maintaining full alloy chemistry of the wear-resistant layer)
Excellent bonding quality when properly executed
Consistent overlay thickness and composition
Cost-effectiveness for standardized plate dimensions

The bonding quality is verified through bend tests, peel tests, or bond strength tests per ASTM A263/A264 or EN 10028-7 requirements.

Application Areas

The document reviews major industrial applications for wear-resistant overlay plates:

Mining equipment: Crusher liners, conveyor chutes, bucket teeth, and pump impellers
Cement industry: Kiln linings, mill liners, slide ways, and chutes
Power generation: Boiler furnace walls, cyclone separators, and fly ash handling
Mining and processing: Ball mill liners, grinding media, and slurry pumps
Agricultural machinery: Plowshares, cultivator shoes, and grain handling equipment

Quality Control and Testing

The study emphasizes the importance of comprehensive quality control for overlay plates:

Hardness testing: Vickers hardness mapping across the overlay thickness and plate surface
Metallographic examination: Interface examination for cracks, unmelted particles, and intermetallic formation
Bond strength testing: Peel tests, bend tests, or tensile shear tests
Wear testing: ASTM G65 (pin-on-disk), ASTM G98 (block-on-ring), or industry-specific wear simulators
Chemical analysis: Verification of overlay composition within specification limits

Domestic Development Progress

By 1990, Chinese research institutions including HWRI had made significant progress in developing indigenous overlay technologies:

Development of proprietary flux compositions for specific overlay materials
Optimization of multi-pass SAW procedures for Chinese industrial consumables
Standardization efforts leading to what would become GB/T 150 and NB/T 47014 requirements
Industrial application demonstration in cement, mining, and power generation sectors

Study Reflections

This 1990 publication serves as a valuable historical document that captures the state of overlay cladding technology at a critical juncture in China's industrial development. The systematic comparison of different technologies provides a framework that remains relevant today, even as new technologies (laser cladding, cold spray, plasma arc cladding) have emerged. The emphasis on dilution control, hardness uniformity, and bond strength as key quality indicators remains fundamental to overlay plate engineering. For contemporary engineers, this work provides useful context for understanding the evolution of Chinese welding technology and the foundational research that enabled subsequent advances. The document also highlights the importance of technology selection based on application requirements — there is no single "best" overlay technology, only the most appropriate choice for specific service conditions, production volumes, and cost constraints.