采用2kW光纤激光器对16mm以下Q235-A碳钢进行切割，以3mm及10mm为例进行工艺分析。在工艺优化后，对各样件进行分析。分析了焦点距离、激光功率、离焦量、气压各参数对切缝形貌、粗糙度、条纹的影响。结果表明，与传统的激光器不同，光纤激光切割3mm的碳钢一般为正离焦，切割10mm碳钢一般选择负离焦。切割薄板时，为了提高速度，一般选择高功率、高气压切割。切割厚板时，确保切面质量，一般选择高功率、低气压。

Experiments of high power laser cutting Q235-A mild steel under 16mm have been performed with 2kW fiber laser. This paper takes cutting 3mm and 10mm Q235-A mild steel for examples. After optimizing the process, the samples are analysed. The influence of the different cutting parameter to cutting quality such as laser power, focus position, foucusing distance, assistant gas pressure has been analysed. The result show that fiber taser always use postive focus to cutting 3ram mild steel, while negative focus always be used in cutting 10mm mild steel. High power and high pressure of assist gas are chosed to improve speed when cutting thin plate. However,high power and low assist gas are chosed when cutting thick plate to satisfy quality.