Investigation of the Surface Integrity of Q345 Steel After Nd:YAG Laser Cleaning of Oxidized Mining Parts

Abstract

As a common mechanical material for mining machinery, Q345 is prone to oxidation due to the moist working environment. At present, laser cleaning is often used to remove rust oxides from the substrate. The pollutant of mining machinery is comprised of a heavy oxide layer and organic ingredients, which are difficult to remove and require high energy per pulse. However, excessive energy is capable of easily destroying surface integrity, such as increasing surface roughness (Ra), generating ablative pits, oxidizing, decreasing microhardness (HV), and decreasing corrosion resistance. Therefore, this paper focused on investigating the surface integrity of mining parts under different laser powers, repetition rates and overlapping rates of the laser spots. The results showed that the surface integrity of the samples gradually improved as the energy per pulse and overlapping rates increased. However, excessive energy caused a negative effect on surface integrity. Based on the comprehensive analysis, optimal parameters were obtained when the power was 280 W, the repetition rate was 10 kHz (pulse duration 84 ns), and the overlapping rate of the laser spot was 70%. This work can provide theoretical guidance for the laser cleaning of mining machinery.

Effect of Different Laser Parameters on Surface Physical Characteristics and Corrosion Resistance of 20 Steel in Laser Cleaning

“…Zhang et al [12] identified that at low energy densities, the primary mechanism of laser cleaning of metal oxides is ablation, where high-energy pulsed lasers not only cause phase explosion but also facilitate oxide layer removal through pressure-induced shock effects. Ma et al [13] employed a fiber laser to remove rust oxides from Q345 steel commonly used in the mining industry and explored the surface integrity at different laser powers to determine the optimum cleaning parameters and confirm the feasibility of laser cleaning. Xing et al [9] investigated rusty steel using a combination of molten salt pretreatment and laser cleaning, noting an enhanced ease of rust layer removal at lower laser irradiation intensities.…”

Determining the Level of Structural and Mechanical Degradation of Steel in the Supporting Structure of Mining Excavation Machinery

“…At the same time, the authors propose solutions to modernize the mechanical units and structural parts, which can reduce the negative impact of the new operating conditions on the mining machine [11]. There are numerous studies on the behaviour of this mechanical material frequently used in the construction of the component parts of mining equipment [1][2][3], the failure behavior and the degree of wear of the component material of the load-bearing structure of heavy machinery [5], deformation characteristics [9], the stresses applied to some component parts of the excavators [12][13][14].…”

Multi-Objective Optimization of Laser Cleaning Quality of Q390 Steel Rust Layer Based on Response Surface Methodology and NSGA-II Algorithm

“…As industrial demand grows, research on the process parameters, surface quality, and performance of laser cleaning is expanding. For example, Ma et al [10] conducted single-factor experiments to investigate the effects of laser cleaning on the rust layer of Q345 steel used in mining machinery. They specifically examined the influences of laser power and spot overlap rate on the post-cleaning surface integrity, ultimately determining optimal cleaning process parameters.…”