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采用Fe基合金粉末在Q235D钢表面进行多层激光熔覆实验,得到的熔覆层表面比较光滑平整、粗糙程度较小,没有宏观裂纹和气孔出现,通过金相组织观察发现熔覆层组织晶粒的尺寸比较细小,熔覆层组织较好,无裂纹,基本无气孔出现,熔覆层与基体冶金结合较好。实验分别采用不同的层间停光时间进行多层激光熔覆,结果发现:多层熔覆时当停光时间较短时,熔覆层整体的显微硬度值会随着熔覆层数的增加而有所下降,并且熔覆层硬度的变化规律为:与基体结合的第一熔覆层硬度最高,往上层依次逐级降低,最后一层的硬度最低;当停光时间较长时,熔覆层的整体显微硬度值同样也会随着熔覆层数的增加而降低,而各熔覆层变化规律有所不同的是与基体结合的第一熔覆层硬度最低,往上层依次逐级升高,最后一层的硬度最高。实验结果对实际生产有重要的研究和应用价值。
Multi-layer laser cladding experiments were carried out on the surface of Q235D steel with Fe-based alloy powder. The surface of the cladding layer was smoother and smoother, with less roughness and no macroscopic cracks and pores. The microstructure of cladding layer The grain size is relatively small, the cladding structure is better, no cracks, no porosity, the cladding layer and the substrate metallurgical bonding is better. The experiments were carried out using different layers of light-off time for multi-layer laser cladding, the results showed that: when the multi-layer cladding time is shorter, the overall micro-hardness of the coating layer with the number of cladding The hardness of the coating changes with the following rules: the hardness of the first cladding layer combined with the matrix is the highest, and the hardness of the final layer is the lowest in the upper layer, while the hardness of the last layer is the lowest; when the stop time is longer, The overall microhardness value of the cladding layer also decreases with the increase of the cladding layer number. The variation of each cladding layer is different from the lowest hardness of the first cladding layer combined with the substrate. Step by step, the last layer of the highest hardness. Experimental results on the actual production of important research and application value.