Q235D激光熔覆实验研究

The Study of Laser Cladding on Q235D

在Q235D钢表面激光熔覆Fe基合金粉末,通过对熔覆层外观形貌、表面硬度、金相组织和显微硬度的对比分析得出了双层熔覆时的最优工艺参数,当两层工艺参数相同且均为:激光功率600W、扫描速度2mm/s、搭接率24.2%、送粉电压10V时,所得熔覆层的表面较为平整均匀,通过金相组织分析发现,基体与熔覆层的冶金结合性较好,无裂纹,并且基本无气孔出现,熔覆层的显微硬度显著高于基体且从熔覆层→过渡区→基体呈梯度降低。在两熔覆层交界处,显微硬度从界面处往第一熔覆层方向先减小后增加直到最高值,从界面处往第二熔覆层方向显微硬度呈阶梯状上升逐渐增加到熔覆层硬度的最高值,尽管两熔覆层交界处显微硬度有所降低,但是仍然大大高于基体的显微硬度,对熔覆层性能基本无影响,在工业生产中有着较好的发展前景。

It coates the Q235D steel with Fe-based alloy powder by laser cladding. Through comparing the cladding layer appearance, hardness, metallographic structure and microhardness, it concludes that the cladding layer is more smooth, and cladding metallurgical bonding layer is better, and no crack and almost no hole appears when the two cladding layer process parameters（laser power：600W, scan speed：2mm/s, overlap rate ：24.2%, the feedingvoltage：10V）are same. Microhardness of the cladding layer is higher than the base and decreases fiom the cladding layer to the base gradient. At the junction of the two cladding layers, the microhardness decreases firstly fiom interface to the direction of the first cladding layer then increases to the peak, and gradually increases from interface to the direction of the second cladding layer to the peak. Even though the microhardness at the junction of the two cladding layer decreases slightly, it is still much higher than the hardness of the base and almost has no effect on the Cladding layer performance. It has good prospects for development in the industrial production.