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 (R_a), 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.

中文翻译：

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N345：YAG激光清洗氧化采矿部件后Q345钢的表面完整性研究

作为采矿机械的常见机械材料，Q345由于潮湿的工作环境而易于氧化。目前，经常使用激光清洁从基材上去除锈蚀氧化物。采矿机械的污染物由重的氧化物层和有机成分组成，这些成分很难去除，每脉冲需要​​高能量。但是，过多的能量会轻易破坏表面完整性，例如增加表面粗糙度（R _a），产生烧蚀坑，氧化，降低显微硬度（HV）和降低耐蚀性。因此，本文着重研究在不同激光功率，重复率和激光点重叠率下采矿零件的表面完整性。结果表明，随着每脉冲能量和重叠率的增加，样品的表面完整性逐渐提高。但是，过多的能量会对表面完整性产生负面影响。在综合分析的基础上，获得功率为280 W，重复率为10 kHz（脉冲持续时间为84 ns），激光光斑的重叠率为70％时的最佳参数。这项工作可以为矿山机械的激光清洗提供理论指导。