Sintered Wear-Resistant and Heat-Resistant Hardfacing Electrode Under High-Speed Abrasive Conditions

Literature Overview

Published in 2008 by Xue Wentao and colleagues from the Beijing Research Institute of Mining and Metallurgy, this study examines the wear resistance of sintered-type hardfacing electrodes under high-speed frictional wear conditions. The research addresses a critical gap in hardfacing technology: the performance of wear-resistant coatings when subjected to elevated sliding velocities that generate significant frictional heat, simulating conditions encountered in mining, material handling, and high-speed grinding applications.

Technical Approach and Results

The investigation focused on the alloy composition of the sintered electrode and its behavior during high-velocity sliding contact. The sintered electrode fabrication method involves compacting alloy powder, followed by vacuum sintering to achieve a homogeneous, defect-free electrode rod. This approach differs fundamentally from traditional cast or forged electrodes, as the sintered microstructure offers superior control over phase distribution and composition uniformity.

The experimental results confirmed that the sintered hardfacing electrode exhibits good wear resistance under high-speed friction conditions. The key advantage lies in the ability to maintain coating integrity even when frictional heating raises surface temperatures significantly during operation.

Application Context and Engineering Relevance

High-speed abrasive wear represents a particularly challenging regime because the combination of elevated sliding velocity and contact pressure generates substantial localized heat, which can soften the hardfacing layer, promote oxidative wear, and accelerate material loss. Industries such as cement production (kiln rollers), mining (crusher hammers), and power generation (grinding mills) all face this challenge.

The sintered electrode approach offers several engineering advantages:

• Powder metallurgy allows precise alloy composition design, enabling optimization of carbide type, size, and distribution
• The absence of casting defects (segregation, shrinkage porosity) provides a more reliable starting material for the weld deposit
• Uniform electrode composition ensures consistent weld layer properties throughout the deposition
• The sintering process can incorporate refractory carbides (WC, TiC, Cr7C3) in controlled quantities and morphologies

Process Considerations

When specifying sintered hardfacing electrodes for high-speed wear applications, engineers should consider the following:

1. Base material compatibility: The coefficient of thermal expansion mismatch between the sintered deposit and the base steel must be evaluated to prevent cracking during thermal cycling
2. Welding procedure: Sintered electrodes may require modified welding parameters compared to cast electrodes due to differences in electrical resistivity and thermal conductivity
3. Interlayer design: For thick deposits, a graded interlayer between the base and the sintered hardfacing layer may be necessary to manage residual stresses
4. Post-weld heat treatment: Stress-relief annealing should be specified to minimize the risk of delayed cracking in the heat-affected zone

Summary

This study validates the sintered powder metallurgy approach as a viable pathway for producing hardfacing electrodes with superior performance under high-speed abrasive conditions. The uniformity and composition control offered by the sintering process translate directly into more predictable wear behavior in service. For engineers selecting hardfacing materials for high-velocity applications, sintered electrodes represent a premium option that warrants consideration despite potentially higher material costs. The work from Beijing Research Institute of Mining and Metallurgy contributes valuable data to the design of wear-resistant surfaces for demanding industrial applications.