材料成型及控制工程專業(yè)英語Mechanicalproperty機械性能austenitic奧氏體的martensite馬氏體Plasticdeformation塑性變形stressconcentrator應力集中點bar棒材beam線材sheet板材ductile可延展的stressrelief應力松弛austenitie奧氏體martensite馬氏體normalize正火temper回火anneal正火harden淬火close-dieforging模鍛deformationrate變形速度diffusion擴散overheat過熱Workhardening加工硬化dislocationdensity位錯密度die模具residualstrain殘留應變as-forged鍛造的injectionmold注射模moldingshop成型車間clampingforce合模力grind磨削dropstamping錘上模鍛nickel-basesuperalloy鎳基合金insulation隔熱burr毛刺injectioncapacity注射容量deterioration變化、退化discrete不連續(xù)的abrasive磨損welding焊接metallurgical冶金的Formationofaustenite奧氏體轉變Thetransformationofpearlite（珠光體）intoaustenitecanonlytakeplaceattheequilibriumcriticalpoint（臨界溫度）averyslowheatingasfollowsfromtheFe-Cconstitutionaldiagram（狀態(tài)圖）?undercommonconditions,thetransformationisretardedandresultsinoverheating,i.e.occursattemperaturesslightlyhigherthanthoseindicatedintheFe-Cdiagram.TheendofthetransformationiScharacterizedbytheformationofausteniteandthedis—appearanceofpearlite（ferrite+cementite）?ThisausteniteishoweverinhomogeneouseveninthevolumeofasinglegrainInplacesearlieroccupiedbylamellae（層片）（orgrains）ofapearliticcementite,thecontentofcarbonisgreaterthaninplacesofferriticlamellae?Thisiswhytheaustenitejustformedisinhomogeneous?Inordertoobtainhomogeneous（均勻的）austenite,itisessentialonheatingnotonlytopassthroughthepointoftheendofpearlitetoaustenitetransformation,butalsotooverheatthesteelabovethatpointandtoallowaholdingtimetocompletethediffusion（擴散）processesinaus-tenitiegrains?為了獲得均勻的奧氏體，在加熱過程中通過珠光體的結束點向奧氏體轉變是必要的，而且對過熱剛以上的點，允許持續(xù)一定時間來完成奧氏體晶粒的擴撒過程。Forging鍛造Technically,forgingmaybedefinedastheprocessofgivingmetalincreasedutilitybyshapingit,refiningit,andimprovingitsmechanicalpropertiesthroughcontrolledplasticdeformationunderimpactandpressure?從技術上說，鍛造可以定義為一種通過在沖擊力或壓力作用下產生可控的塑性變形使金屬成型、細化及改善金屬機械性能來賦予其增加的功效的一種工藝。Withoutforgingsandtheperformancechar-acteristicstheyprovide—autos,airplanes，trucks,farmimplements,earthmovingmachines，missiles，industrialenginesandmachines，andtheimplementsofnationaldefense，asweknowthem，wouldnotbefeasible?正如我們所知，沒有鍛件以及他們優(yōu)良性能，汽車、飛機、卡車、農具、挖土機、導彈、工業(yè)發(fā)動機、機器和國防工具都不可能得到。Closed-Dieforging閉式模鍛Themainfactorsneedingcarefulcontrolinachievingan‘as-forged'structurewhichisbothpredictableandreproducibleintermsofresidualstrain/grainstructuresare:dieperformgeometry；diepreheatingtemperature；lubrication/insulation；kineticenergyinput；continu-almonitoringofworkpiecesurfacetemperature為了得到鍛后組織（這種組織可通過殘余應變/晶粒組織進行預測和復制）需嚴格控制的因素包括：模具成型形狀、模具前處理、潤滑/隔熱、動能輸入、工件表面溫度的持續(xù)監(jiān)控.選擇填空：1、TheyarejustiffedonlybyessentialimproVementsinpropertiessuchashigherstrengthorimprovedcorrosionresistance（耐腐蝕）2、Castironshaverelativelylowmeltingtemperatureandliquidphaseviscosities（粘度），donotformundesirablesurfacefilmswhenpoured，andundergomoderateshrinkage（收縮）duringsolidify-cationandcooling.3、Diesmayhavetobereplacedforanumberofreasonssuchaschangesindimensionsduetowearorplasticdeformation（退化），deteriorationOfthesurfacefinish，breakdownoflubrication，andcrackingorbreakage?因為下面許多原因，模具可能必須更換，例如，由于磨損或塑性變形而引起的尺寸改變、光潔度降低、潤滑故障和裂紋或破損。4、Inhotimpressiondieforgingtheprincipalmodesofdiefailureareerosion,thermalfatigue（熱疲勞）,mechanicalfa-tigueandpermanent（plastic）deformation.在熱壓模鍛中，模具失效的主要形式是腐蝕、熱疲勞、機械疲勞和永久性變形。5、Thiscontactcausethesurfacelayerstoexpand,and,becauseoftheverysteeptemperaturegradients,thesurfacelayersaresubjecttocompressivestres