激光淬火工艺对小麦磨粉机磨辊表面硬度及磨损性能的影响

Effect of laser quenching process on surface hardness and wear performance of wheat grinder roller

【目的】研究激光淬火后小麦磨粉机磨辊表面材料性能变化,解决磨辊磨损严重、使用寿命较短等问题。【方法】采用响应曲面的旋转二次组合设计原理,按照3因素5水平试验方法建立激光功率、光斑直径、扫描速度与磨辊材料表面硬度的数学模型,分析激光功率、光斑直径与扫描速度3因素及各因素间的交互作用对磨辊金属材料表面硬度的影响规律,找出最优的参数组合,探讨淬火后磨辊表面材料的磨损机理。【结果】激光功率、光斑直径与扫描速度对磨辊材料表面硬度影响显著;激光功率、光斑直径和扫描速度对磨辊材料表面硬度的影响依次由强到弱;最优工艺参数组合为激光功率190 W、光斑直径0.70 mm、扫描速度220 mm/s,该参数组合下得到的试样表面硬度为688.67 HV,比原始硬度提升了35%;经激光淬火最优参数组合处理的试样磨损质量损失约为未处理试样的7%;经激光淬火后的磨辊表面材料与小麦粉料间的摩擦磨损作用减弱,小麦粉料在试样表面产生的划痕较轻较短,沟槽更加浅窄。【结论】磨辊表面材料经激光淬火处理后其抗小麦粉料磨损性能明显增强。

【Objective】To study properties of surface material of wheat grinder roller after laser quenching,and solve the problems of grinding roller such as serious wear and short service life.【Method】Using the principle of rotating combination design of response surface,a mathematical model of laser power,spot diameter and scanning speed with surface hardness of grinding roller material was established according to three-factor and five-level test method.The effects of laser power,scanning speed,spot diameter and reciprocal action among three factors on grinding roller surface hardness were analyzed.The optimal parameter combination was obtained.The wear mechanism of surface material of the grinding roller after quenching was investigated.【Result】Laser power,spot diameter and scanning speed significantly affected surface hardness of grinding roller material.The effects of laser power,spot diameter and scanning speed on surface hardness of grinding roller material weakened successively.The optimal technological parameter combination was laser power 190 W,spot diameter 0.70 mm and scanning speed 220 mm/s and the sample surface hardness obtained was 688.67 HV, which was 35% higher than originalhardness. The mass loss of sample treated by optimal laser quenching parameter combination in wear process wasabout 7% of the untreated sample. The friction between grinding roller surface material and wheat powder materialafter laser quenching weakened. The scratches of wheat powder material on sample surface were lighter andshorter. The grooves were shallower and narrower. 【Conclusion】The wear resistance against wheat powdermaterial of grinding roller surface material is obviously enhanced after laser quenching treatment.