激光强化灰铸铁导轨的微观组织及磨损性能.pdf

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1、第41卷第4期中国激光Vo1．41，NO．42014年4月CHINESEJOURNALOFLASERSApril，2014激光强化灰铸铁导轨的微观组织及磨损性能邓猛王义强谷岩袁修华闫国琛／太原科技大学机械工程学院，山西太原030024、＼浙江大学宁波理工学院机电与能源工程学院，浙江宁波315100／摘要采用正交实验优化了激光加工导轨试样的工艺参数，用光学显微镜、扫描电镜和显微硬度计对试样进行了显微组织分析和硬度测试，并在油润滑下与常规处理试样进行了磨损性能对比试验。结果显示，电流对硬化深度影响最显著，然后依次为扫描速度、脉宽和频率，优化后的

2、激光加工参数：扫描速度为0．25mm／s，电流为150A，脉宽为10ms，频率为7Hz。激光加工试样熔凝区分布有球状石墨，相变区晶粒尺寸较熔凝区更细小，分布更均匀；硬度较常规处理有显著提高，其分布无变化梯度。当循环次数达38000时，激光加工试样较常规处理试样耐磨性提高约1倍。关键词激光技术；激光强化；导轨；参数优化；显微组织；显微硬度；耐磨性中图分类号TG143．2；TG163文献标识码Adoi：10．3788／CJL201441．0403009MicrostructureandWearBehaviorofLaserHardenedGra

3、yCastIronGuidewayDengMeng'WangYiqiang。GuYan。YuanXiuhua。YanGuochen'。CollegeofMechanicalEngineering，TaiyuanUniversityofScienceandTechnology，Taiyuan，Shanxi030024，ChinaCollegeofMechanicalandEnergyEngineering，NingboInstituteofTechnology，Zh~iangUniversity，Ningbo，Zhejiang315100，C

4、hinaAbstractThelaserprocessingparametersofthesampleguidewayareoptimizedthroughorthogonalexperiment．Themicr0structureanalysisandhardnesstestofthelaser—treatedsamplearecarriedoutbyopticalmicroscopy，scanningelectronmicroscope(SEM)andmicrohardnesstester，andacontrasttestofwear—

5、resistancebetweenthelaser．treatedandnormallytreatedsamplesiSconductedinoil．1ubricatedconditions．Theresultsshowthathardeningdepthisinfluencedmoststronglybycurrent，followedsuccessivelybyscanningspeed，pulsewidthandfrequency．Theoptimizedlaserprocessingparametersareasfollows：0．

6、25mm／sforscanningspeed，15OAforcurrent，10msforpulsewidth，and7Hzforfrequency．Thespheroidalgraphiteisobservedinthemeltedregionofthelaser—treatedsample．Thegrainsizeinthephasetransformationregionismuchsmallerthanthatinthemeltedregionandthegrainismoreevenlydistributed．Comparedwi

7、ththenormaltreatment，laserprocessingproducesadramaticimprovementinhardnesswithoutvariationofgradientindistribution．Whenthecyclenumberreaches38000，thewear—resistanceofthelaser+treatedsampleisalmostonetimehigherthanthatofthenormallytreatedone．Keywordslasertechnique；laserhard

8、ening；guideway；parameteroptimization；microstructure；micrOhardness；wear．resistanceOCIScode