激光淬火工艺参数对层深及硬度影响敏感性研究

为了了解激光功率和扫描速度变化对淬火层深和表面硬度影响的敏感性,从实验和理论模拟两方面开展了相关研究.在满足激光输入能量相等的条件下,采用按相同倍率提高激光功率或降低扫描速度的方法,研究淬火层深和表面硬度的相应变化.研究结果表明,按相同倍率改变激光功率或扫描速度均会对层深产生明显影响,而激光功率变化的影响更大;但仅改变激光功率或扫描速度不会对表面硬度产生很大影响,相对而言,扫描速度变化对表面硬度的影响略大一些.进一步通过对激光扫描温度场及加热、冷却速度的理论模拟,对上述研究结果做出了合理的理论解释.

Influence of laser processing parameters on the case-depth and the hardness

Both from experiments and theoretical analysis, the influenceof laser processing parameters on the case-depth and the hardness in laser quenching was studied. Under the condition of equal input laser energyand different laser power and scanning velocity, the variation of the case-depth and the hardness was measured. Measurement results show that the change of both the laser power and the scanning velocity can affect the case-depth and the hardness obviously and the change of laser power affects the case-depth more significantly. On the other hand, the change of either the laser power or the scanning velocity has a little influence on the hardness. Correspondingly, the change of the scanning velocity has a little more influence on the hardness. By means of analytical simulation of the temperature distribution and the heating/cooling rates under the laser scanning, reasonable explanation for the results was put forward.