Excessive heating of the metal sheet during laser oxygen cutting can cause quality deterioration and even lead to cut loss and possible machine idle time, especially for cutting of thick plates, where the cutting speed is slower. There are at least three different strategies to handle quality deterioration by heat accumulation in flame laser cutting of thick plates: to optimize the process parameters for preheated zones, to generate tool paths that avoid such regions, or to use active cooling to remove the excessive heat. For any of these strategies to work, it is crucial to correctly identify when and where heat accumulations occur. This can be done by real-time temperature measurements, by simulating heat propagation on the metal plate, or by defining empirical criteria based on experimental data. This paper takes a close look at these methods of heat accumulation detection, their advantages and disadvantages, and how they can be integrated into different approaches to tackle unwanted heat accumulations in laser cutting. Furthermore, three case studies are provided, one for each above-mentioned method, where the detection of quality degradation due to heat accumulation is demonstrated with a series of experiments. For all case studies, at least one action is proposed to improve the cut quality. All experiments were conducted for 15 mm mild steel plates using a 4 kW industrial fiber laser cutting machine.

中文翻译：

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预测厚金属板激光氧气切割中的热量积聚

激光氧气切割过程中金属板过热会导致质量下降，甚至导致切割损失和可能的机器闲置时间，尤其是切割厚板时，切割速度较慢。至少有三种不同的策略来处理厚板火焰激光切割过程中因热量积累而导致的质量下降：优化预热区的工艺参数，生成避开这些区域的刀具路径，或使用主动冷却去除过多的热量. 对于这些策略中的任何一种，正确识别热量积累发生的时间和地点至关重要。这可以通过实时温度测量、模拟金属板上的热传播或根据实验数据定义经验标准来完成。本文仔细研究了这些热量积聚检测方法、它们的优缺点，以及如何将它们集成到不同的方法中以解决激光切割中不需要的热量积聚问题。此外，还提供了三个案例研究，一个针对上述每种方法，其中通过一系列实验证明了由于热量积累导致的质量下降的检测。对于所有案例研究，建议至少采取一项措施来提高切割质量。所有实验均使用 4 kW 工业光纤激光切割机对 15 mm 低碳钢板进行。上述每种方法都有一个，其中通过一系列实验证明了由于热量积累导致的质量下降的检测。对于所有案例研究，建议至少采取一项措施来提高切割质量。所有实验均使用 4 kW 工业光纤激光切割机对 15 mm 低碳钢板进行。上述每种方法都有一个，其中通过一系列实验证明了由于热量积累导致的质量下降的检测。对于所有案例研究，建议至少采取一项措施来提高切割质量。所有实验均使用 4 kW 工业光纤激光切割机对 15 mm 低碳钢板进行。