材料成型及控制工程專業(yè)英語

材料成型及控制工程專業(yè)英語Mechanicalproperty機(jī)械性能austenitic奧氏體的martensite馬氏體Plasticdeformation塑性變形stressconcentrator應(yīng)力集中點(diǎn)bar棒材beam線材sheet板材ductile可延展的stressrelief應(yīng)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(kuò)散overheat過熱Workhardening加工硬化dislocationdensity位錯密度die模具residualstrain殘留應(yīng)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(zhuǎn)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(kuò)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(jié)束點(diǎn)向奧氏體轉(zhuǎn)變是必要的，而且對過熱剛以上的點(diǎn)，允許持續(xù)一定時間來完成奧氏體晶粒的擴(kuò)撒過程。Forging鍛造Technically,forgingmaybedefinedastheprocessofgivingmetalincreasedutilitybyshapingit,refiningit,andimprovingitsmechanicalpropertiesthroughcontrolledplasticdeformationunderimpactandpressure?從技術(shù)上說，鍛造可以定義為一種通過在沖擊力或壓力作用下產(chǎn)生可控的塑性變形使金屬成型、細(xì)化及改善金屬機(jī)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(jī)、卡車、農(nóng)具、挖土機(jī)、導(dǎo)彈、工業(yè)發(fā)動機(jī)、機(jī)器和國防工具都不可能得到。Closed-Dieforging閉式模鍛Themainfactorsneedingcarefulcontrolinachievingan‘a(chǎn)s-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(yīng)變/晶粒組織進(jìn)行預(yù)測和復(fù)制）需嚴(yán)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?yàn)橄旅嬖S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(jī)械疲勞和永久性變形。5、Thiscontactcausethesurfacelayerstoexpand,and,becauseoftheverysteeptemperaturegradients,thesurfacelayersaresubjecttocompressivestres