模具材料激光表面强化技术研究

【作者】 况敏；

【导师】 苏玉长； 周克崧；

【作者基本信息】 中南大学 ， 材料物理与化学， 2011， 硕士

【摘要】 激光表面相变硬化淬火是一种新兴的表面改性技术,该技术有利于淬火层晶粒细化、金属表层强化及金属表面耐磨性提高。论文采用DL-HL-10000B二氧化碳激光器对3Cr2W8V热作模具钢和Cr12MoV冷作模具钢进行激光表面淬火处理。研究了淬火工艺如激光功率、扫描速度、光斑尺寸以及搭接率等参数对淬火层显微组织结构、硬化层深度和硬度的影响,得到如下结论：1.对3Cr2W8V模具钢,激光相变硬化淬火优化工艺参数是：3500W激光功率,30mm×1mm激光光斑,0.8mm-0.85m/min激光扫描速度,1mm－2mm激光光斑搭接尺寸；经激光相变硬化淬火处理后表面处理层组织为均匀的超细晶高位错密度淬火马氏体和含过饱和碳的残余奥氏体。2.对Cr12MoV模具钢,激光相变硬化淬火优化工艺参数是：3500W激光功率,30mm×1mm激光光斑,激光扫描速度0.8mm－0.85m/min,lmm－2mm激光光斑搭接尺寸；经激光相变硬化淬火处理后表面处理层组织为均匀的超细晶高位错密度淬火马氏体和含过饱和碳的残余奥氏体。3.3Cr2W8V模具钢表面激光相变硬化淬火后,表面处理层硬度较基体提高超过1.5倍。摩擦磨损实验表明,表面处理层发生轻微的磨粒磨损；未处理表面磨损严重,磨损表面发生粘着磨损,观察到了粘着脱落坑。激光相变硬化淬火处理表面磨损失重较未处理表面减少50.12%。4.Cr12MoV模具钢表面激光相变硬化淬火后,处理层硬度较基体提高1.5倍,耐磨性能较基体提高1倍；摩擦磨损实验表明,表面处理层轻微磨损,磨损表面仅为犁沟；未处理表面磨损严重,未激光处理的磨损样犁沟较深,发生磨损疲劳并出现了疲劳台阶。更多还原

【Abstract】 Laser hardening is a new surface modification technology, which is conducive to grain refinement hardening layer, to the strengthening and improvement of the wear resistance for the metal materials.Papers with DL-HL-10000B carbon dioxide laser on 3Cr2W8V hot die steel and die steel Cr12MoV cold laser surface hardening treatment. Of quenching processes such as laser power, scanning speed, beam parameters such as size and overlap of the quenching rate of layer microstructure, case depth and hardness, the following conclusions:1. On 3Cr2W8V die steel, laser transformation hardening quenching optimal parameters are:3500W laser power,30mm×lmm laser spot, 0.8mm-0.85m/min laser scanning speed, 1mm-2mm overlap the laser spot size; by laser Transformation hardening quenching surface layer for the uniform quenching of ultrafine grained high dislocation density saturated with carbon martensite and residual austenite.2. On Cr12MoV die steel, laser transformation hardening quenching optimal parameters are:3500W laser power,30mm×lmm laser spot, laser scanning speed 0.8mm-0.85m/min, lmm-2mm overlap the laser spot size; by laser Transformation hardening quenching surface layer for the uniform quenching of ultrafine grained high dislocation density saturated with carbon martensite and residual austenite.3.3Cr2W8V die steel after quenching laser transformation hardening, surface hardness than the matrix by more than 1.5 times. Friction and wear experiments show that the surface layer of mild wear, the wear of abrasive wear only the furrows; untreated severe surface wear, the wear surface of adhesive wear, adhesive off pit there. Laser surface transformation hardening quenching wear weight loss decreased 50.12% compared with untreated surface4. Cr12MoV die steel after quenching laser transformation hardening, hardness treatment 1.5 times higher than the substrate, the wear resistance increased by 1 times higher than the matrix; friction and wear experiments show that the surface layer of minor wear, worn surface furrows only; not Handling severe surface wear, no wear and tear like laser treatment deep furrows, the occurrence of fatigue wear and the emergence of fatigue level.更多还原