共查询到20条相似文献,搜索用时 31 毫秒
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目的与传统激光淬火(CLQ)进行对比研究,获得使用飞行光路的振镜扫描式激光淬火(GLQ)的温度变化特性和规律。方法使用两种淬火方式对45钢进行表面处理,将组织形貌和硬度分布进行比较,并结合数值模拟,研究两种激光淬火方式的温度变化特性和规律。结果在相同的总能量输入、扫描区域和扫描时间下,两种淬火方式硬化层横截面形貌呈现巨大差异:CLQ试样硬化层深度为753.66μm,宽度为3787.21μm,横截面形貌为"月牙形";GLQ试样硬化层深度为256.61μm,宽度为5808.77μm,形貌为"均匀性更好的近似月牙形"。截面硬度分布相似:均为中间主体区域高(GLQ试样硬度810~900HV,CLQ试样硬度790~830HV),两侧边缘区域低(均约为760HV)。模拟结果表明,CLQ试样特征点激光辐照时长共1.25 s,温度从508℃变为1063℃,奥氏体相变时间为1.17 s;GLQ试样特征点激光辐照时长共0.628 s,温度从500℃变成718℃,其波峰温度奥氏体相变时间为0.38 s,波谷温度均保持在马氏体转变温度以上。沿激光扫描方向,GLQ的温度变化率比CLQ大1个数量级;垂直激光扫描方向,GLQ温度变化率比CLQ大2个数量级。结论GLQ具有温度变化率更大、升降温多次循环、热处理相变时间更短、热积累更小等特点,有望在薄层大面积淬火上获得应用。 相似文献
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Laser surface hardening of gray cast iron used for piston ring 总被引:2,自引:0,他引:2
Jong-Hyun Hwang Dae-Young Kim Joong-Geun Youn Yun-Sig Lee 《Journal of Materials Engineering and Performance》2002,11(3):294-300
The process parameters for laser surface-hardening has been experimentally established for improving the wear life of piston
rings used for marine diesel engines by the formation of a proper hardened layer on it. The parameters of interest were the
laser power and travel speed. Various hardened layers of gray cast iron were analyzed with respect to microstructure, hardness
value, hardening depth, surface roughness, and wear resistance. The hardness of the laser-hardened layer was in a range between
840 and 950 Hv0.1, regardless of the laser power and travel speed range studied. Both the surface roughness and hardening
depth increased in an almost linear manner with the increase in the heat input applied. Thus, the hardened layers formed with
heat input ranges between 30 and 45 J/mm satisfied the piston ring application requirements for surface roughness (<6.3 μm
in Ra) and the minimum effective hardening depth of 0.3 mm (>450 in Vickers number). Wear-test results obtained using a pin-on-disk-type
wear-test machine showed that the wear life of the laser-hardened layer was almost twice that of the untreated one. This was
directly attributed to the formation of the martensitic microstructure. 相似文献
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为了提升凸轮表面耐磨性,采用YLS-4000型光纤激光器通过不同的激光功率对基体材料45钢表面进行激光淬火。通过SEM观察激光淬火前后材料表面和界面形貌,金相显微镜观察组织形貌,通过HVS-1000A型显微硬度仪测试了试样表面硬度,并测试了试样的摩擦因数和磨损形貌。结果表明:淬火层界面显微组织为淬火马氏体及少量残余奥氏体,在激光功率1 000~1 800 W时分别获得淬硬层深度为0.3~0.8mm的单道热影响区;淬硬层硬度分布基本均匀,平均硬度约为547~765HV,比基体硬度提高了2~3倍,激光淬火后组织细化和形成大量马氏体是硬度提高的主要原因;在一定激光功率范围内(1 200~1 800 W),激光淬硬层的抗磨损性能比基体有较大的提升,且当激光功率为1 600 W时能获得最佳的磨损性能。 相似文献
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30CrNi2MoVA钢激光相变硬化技术 总被引:1,自引:0,他引:1
研究了30CrNi2MoVA钢激光淬火后淬硬层微观结构特征及工艺参数对硬化层深度和硬度的影响。结果表明,激光淬火硬化层依其组织特征,分为完全淬硬层、过渡层和热影响层;硬化层深度随着激光功率的升高和扫描速度的减小而逐渐增加,表面硬度则存在一个极大值。 相似文献
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J.A. Picas A. Forn M.T. Baile E. Mart n 《International Journal of Refractory Metals and Hard Materials》2005,23(4-6):330-334
The present study describes and compares the mechanical and tribological properties of CrN coatings deposited by PVD/CAPD (Cathodic Arc Plasma Deposition) on three different substrates: steel, aluminium alloy and reinforced aluminium alloy. The coating-substrate interfaces were analysed by scanning electron microscopy (SEM). The ultra-microindentation technique was applied to measure coating hardness. Experiments using a tribometer (pin on disc configuration) under lubricated conditions have been performed in order to evaluate the friction and wear properties of the different systems.
The measured coating hardness depends on the indentation depth reached in the ultra-microindentation tests. In this study the coating-substrate system has been characterized, analyzing the hardness variation from the coating to the substrate by different indentation depths, and modelling the experimental curve with a universally approved mathematical model. The CrN–steel system exhibits the best performance, in which the system hardness is close to the CrN coating hardness. The CrN–AMC system performs better than CrN–aluminium but worse than CrN–steel system. 相似文献
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GCr15钢表面激光淬火的组织与性能 总被引:10,自引:1,他引:9
利用HL-1500无氦横流CO2激光加工机对GCr15钢表面进行激光淬火处理。采用SSX-550型扫描电子显微镜(SEM)、XJL-02A立式金相显微镜(OM)、DMH-2LS努氏显微硬度计、ML-10滑动摩擦磨损试验机和ZF-3恒电位仪等设备对不同功率下相变硬化层的显微组织及性能进行研究。结果表明:相变硬化区的组织为细小针状马氏体和少量球状碳化物,过渡区的组织为马氏体、残留奥氏体、铁素体和碳化物;试样的硬化层硬度比基体提高了2.2~3.5倍,当激光功率为1050W时,硬化层深度最大,可达0.7mm,耐磨性比基体提高3倍,耐蚀性也显著提高。 相似文献
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Jong-Do KIM Myeong-Hoon LEE Su-Jin LEE Woon-Ju KANG 《中国有色金属学会会刊》2009,19(4):941-945
Laser transformation hardening(LTH) is one of the laser surface modification processes. The surface hardening of rod-shaped carbon steel (SM45C) was performed by lathe-based laser composite processor with Gaussian-beam optical head. The LTH characteristics by dominant processes, longitudinal and depth directional hardness distributions and behaviors of phase transformation in hardened zones were examined. Especially, two concepts of circumferential speed and theoretical overlap rate were applied. When laser power increased or circumferential speed decreased, the surface hardening depth gradually increases due to the increased heat input. Moreover, the longitudinal hardness distribution particularly shows periodicity of repetitive increase and decrease, which results from tempering effect by overlap. Finally, the feasibility of laser transformation hardening is verified by using the beam with Gaussian intensity distribution. 相似文献
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分别用激光淬火-表面氮化和表面氮化-激光淬火复合处理工艺方案对4Cr13钢试样进行表面强化处理,然后由实验数据绘制硬度分布曲线和硬化层深度比较表,分析激光淬火与表面氮化的不同组合对材料表面硬化层硬度分布和硬化层深度的影响。结果表明,采用表面氮化-激光淬火复合处理可满足试样表面强化处理的要求。 相似文献
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激光冲击处理对304不锈钢力学性能的影响 总被引:1,自引:0,他引:1
选用不同涂层对304不锈钢板材激光冲击处理,研究了自主研制的硅酸乙脂涂层与几种常用吸收涂层对304不锈钢的硬度和表面残余应力等冲击力学性能的影响.结果表明,在激光冲击过程中,黑漆涂层、铝箔涂层和硅酸乙脂黑漆涂层都能有效提高激光冲击试样的表面硬度,激光连续冲击后,在304不锈钢试件表面能形成1mm厚的硬化层,其表面硬度最大到240HV;随着激光功率密度的增强,其表面硬度逐渐增强;其表面残余应力也随着激光功率密度的增加而逐渐增大. 相似文献