从内到外看德国豹式坦克_部分5.docx

PANTHER© Osprey Publishing 3忘ThroughoutthePanthertank'sproductionrun,itsgunshieldandflamehardenedarmouronthesuperstructuresides,hullsidesandlowernoseplate.AllofthemainplatesofthemodelD,AandGtanksexaminedinthiscountrywere,commander'scupolaweremadeofcasthomogenousarmor(CHA),despitethefactthatCHAdoesnothowever,machineablequalityRHA.offerihe same ballisticprotection levels as rolledhomogenous armor (RHA)plates of similar thickness.The big advantage of CHAis the ability to mold itinto almost any shape.Pictured is a knockedoutPanther Ausf. A tank.(Patton Museum)GGAmodel DtankIPantherexamined inRussiaAnotherbigadvantageofRHAisthatitprovidedsuperiorprotectionwhenstruckbyAPprojectilesduetoitsductility,whichisthepropertyofamaterialthatallowsittowithstandlargeamountsofdeformationbeforefracturing,afeaturelackinginface-hardenedarmor.RHAalsodidwellinprotectingagainsttheshockwavesgeneratedbylarge-caliberAPprojectilesstrikingtheexteriorofatank'sarmor,aswellastheblastfromHEprojectiles.ThebigdisadvantageofRHAisitsinabilitytoformeasilyinotherthanaflatstate.Throughoutitsservicelife,thePanthertankscriesemployedcasthomogenousarmor(CHA)forthegun-shieldandcupola.CHAwasgivenitsshapebycastingandprovidedoptimuinballisticprotectionpropertiesbysubsequentheattreatment.ThebiggestadvantageofCHAwasthatitcanbemoldedintoalmostanyshape,furnishingcurvedsurfacesofanydesiredthickness,henceitsuseinmakinggunshieldsandcupolasonthePanthertank.had132AdisadvantageofCHAisthefactthatitsballisticperformanceispoorerthanthatofRHA.employedonShermantanks.AlthoughallversionsoftheShermantankfeaturedCHAturretsandwereintendedtohaveCHAhulls,alackoffoundriesmeantthatnotallhullswereconstructedofCHA.ManywereconstructedofRHA.TheRedArmyT-34tankshadCHAandRHAturrets,withhullsconstructedsolelyofRHA.ARMORHARDNESSDespitethefactthatAnimportantfactorindeterminingtheabilityofsteelarmorplatetoresistpenetrationbyAPprojectilesisnotjustitsthicknessoritsductility,butitsCHAhashardness.Steel armor plate is heat treated to make it harder. As hardnesspoorerincreases,there is a proportional increase in its resistance to penetration.Picturedis an early model Panther Ausf. D tank, captured by the Red Army during the Battle of Kursk, which hasa complete penetration through the left side superstructure plate. Once inside an armored vehicle, the APprojectile will ricochet within it and become a casualty producer or detonate onboard ammunition. ( PattonMuseum)ballisticperfbrmanccthanRHA,itwasextensivelyThedamage that can hedone to armor plate canvary for numerousreasons, including the sizeand composition of the APprojectile compared to thearmor plate struck and thestriking angle and velocityof the AP projectile.Projectile strikes havegouged out the armor onthe glacis plate of aPanther Ausf. A tank.(Patton Museum)However,there is atradeoff,because asarmoritsductility,whichmeansthatitbecomesmorebrittle.Thisdecreaseinductilityweakensannor'sresistancetopenetration.Torestoretheductilityofsteelarmorplate,itisplacedthroughanadditionalheatingprocessreferredtoastempering,whichreducesbrittlenessandrestoresductility.Thedifficultpartfbrthearmordesignersistodetenninetheannorhardnesslevelthatprovidestheoptimumresistancetopenetration.ThehardnessoftankarmortypicallyisdescribedbyitsBrinellHardnessNumber(BHN).ABrinellhardnesstestdeterminestheBHNandisdescribedinaMarch1950U.S.ArmyreporttitledVulnerabilityofArmoredVehiclestoBallisticAttackastakingahardenedsteelballofspecificphysicaldimensionsandforcingitintoasampleofarmorsteelfbrthirtysecondsundera3,000-kg(6,600-lb)load.BHNisthequotientobtainedbydividingtheappliedload,measuredinkilograms,bytheareaoftheimpression,measuredinsquaremillimeters.hardnessInhisbookTechnologyofTanks,authorRichardM.Ogorkiewiczdescribedtheincreases,evolutionoftheBHNintanks:thereisadecreasein134PROTECTIONSometimesanAPprojectilewillnotpenetrateanarmorplate,butwillpush,ordish,theplateinward,aconditioncalled“bulging."Whilecrackingorcleavingoftheannorplatemayoccur,thereisnoprojectilepenetrationasisseeninthispictureofaPanthertankturretstruckatleastthreetimesbylarge-caliberrounds.(PattonMuseum)Therelativelythin,8to14-mmplatesofsteelarmorusedinthetanksoftheFirstWorldWarwereheattreatedtoaBrinellHardnessNumber(BHN)rangingfrom420toasmuchas650.But,asplatesbecamethickerandwerejoinedbyweldinginsteadofbeingrivetedontoanangleironframework,armorhadtobelesshard.Thus,fromthe1930sonwards,armorplatebecamegenerallyofmachineablequalitysteelwithahardnessrangingfromabout390BH