资源描述：
《机械设计制造专业数控外语文献翻译》由会员上传分享，免费在线阅读，更多相关内容在工程资料-天天文库。
1、实用标准文案本科毕业设计（论文）英语译文院（系）：河北理工大学轻工学院专业：机械设计制造及其自动化姓名：刘卫学号200515160212指导教师评语：签名：年月日精彩文档实用标准文案外语文献翻译摘自:《制造工程与技术（机加工）》（英文版）《ManufacturingEngineeringandTechnology—Machining》机械工业出版社2004年3月第1版美s.卡尔帕基安(Seropekalpakjian)s.r施密德(StevenR.Schmid)著原文：20.9MACHINABILITYThemachinabili
2、tyofamaterialusuallydefinedintermsoffourfactors:1、Surfacefinishandintegrityofthemachinedpart;2、Toollifeobtained;3、Forceandpowerrequirements;4、Chipcontrol.Thus,goodmachinabilitygoodsurfacefinishandintegrity,longtoollife,andlowforceAndpowerrequirements.Asforchipcontrol,
3、longandthin(stringy)curedchips,ifnotbrokenup,canseverelyinterferewiththecuttingoperationbybecomingentangledinthecuttingzone.Becauseofthecomplexnatureofcuttingoperations,itisdifficulttoestablishrelationshipsthatquantitativelydefinethemachinabilityofamaterial.Inmanufact
4、uringplants,toollifeandsurfaceroughnessaregenerallyconsideredtobethemostimportantfactorsinmachinability.Althoughnotusedmuchanymore,approximatemachinabilityratingsareavailableintheexamplebelow.20.9.1MachinabilityOfSteelsBecausesteelsareamongthemostimportantengineeringm
5、aterials(asnotedinChapter5),theirmachinabilityhasbeenstudiedextensively.Themachinabilityofsteelshasbeenmainlyimprovedbyaddingleadandsulfurtoobtainso-calledfree-machiningsteels.ResulfurizedandRephosphorizedsteels.Sulfurinsteelsformsmanganesesulfideinclusions(second-pha
6、separticles),whichactasstressraisersintheprimary精彩文档实用标准文案shearzone.Asaresult,thechipsproducedbreakupeasilyandaresmall;thisimprovesmachinability.Thesize,shape,distribution,andconcentrationoftheseinclusionssignificantlyinfluencemachinability.Elementssuchastelluriumands
7、elenium,whicharebothchemicallysimilartosulfur,actasinclusionmodifiersinresulfurizedsteels.Phosphorusinsteelshastwomajoreffects.Itstrengthenstheferrite,causingincreasedhardness.Hardersteelsresultinbetterchipformationandsurfacefinish.Notethatsoftsteelscanbedifficulttoma
8、chine,withbuilt-upedgeformationandpoorsurfacefinish.Thesecondeffectisthatincreasedhardnesscausestheformationofshortchipsinst
