资源描述:
《美国机械工程师手册_26663_yd5.pdf》由会员上传分享,免费在线阅读,更多相关内容在行业资料-天天文库。
1、HEATTREATMENTOFSTEEL479HARDENING,TEMPERING,ANDANNEALINGHeatTreatmentOfStandardSteelsHeat-TreatingDefinitions.—Thisglossaryofheat-treatingtermshasbeenadoptedbytheAmericanFoundrymen'sAssociation,theAmericanSocietyforMetals,theAmericanSocietyforTestingandMaterials,andtheSocietyofAutomotiveEngineers.S
2、inceitisnotintendedtobeaspecificationbutisstrictlyasetofdefinitions,temperatureshavepur-poselybeenomitted.Aging:Describesatime–temperature-dependentchangeinthepropertiesofcertainalloys.Exceptforstrainagingandagesoftening,itistheresultofprecipitationfromasolidsolutionofoneormorecompoundswhosesolubi
3、litydecreaseswithdecreasingtempera-ture.Foreachalloysusceptibletoaging,thereisauniquerangeoftime–temperaturecom-binationstowhichitwillrespond.Annealing:Atermdenotingatreatment,consistingofheatingtoandholdingatasuit-abletemperaturefollowedbycoolingatasuitablerate,usedprimarilytosoftenbutalsotosimul
4、taneouslyproducedesiredchangesinotherpropertiesorinmicrostructure.Thepur-poseofsuchchangesmaybe,butisnotconfinedto,improvementofmachinability;facili-tationofcoldworking;improvementofmechanicalorelectricalproperties;orincreaseinstabilityofdimensions.Thetime–temperaturecyclesusedvarywidelybothinmaxi
5、mumtemperatureattainedandincoolingrateemployed,dependingonthecompositionofthematerial,itscondition,andtheresultsdesired.Whenapplicable,thefollowingmorespe-cificprocessnamesshouldbeused:BlackAnnealing,BlueAnnealing,BoxAnnealing,BrightAnnealing,CycleAnnealing,FlameAnnealing,FullAnnealing,Graphitizin
6、g,IntermediateAnnealing,IsothermalAnnealing,ProcessAnnealing,QuenchAnnealing,andSpheroidizing.Whenthetermisusedwithoutqualification,fullannealingisimplied.Whenappliedonlyforthereliefofstress,theprocessisproperlycalledstressrelieving.BlackAnnealing:Boxannealingorpotannealing,usedmainlyforsheet,stri
7、p,orwire.BlueAnnealing:Heatinghot-rolledsheetinanopenfurnacetoatemperaturewithinthetransformationrangeandthencoolinginair,tosoftenthemetal.Theformationofabluishoxideonthesurfaceisincidental.BoxAnnealing:Annealing