Iprothokholi nganye yovavanyo (uBrinell, uRockwell, uVickers) uneenkqubo ezithe ngqo kwinto ephantsi kovavanyo.I-Rockwell t-test iluncedo ekuvavanyeni imibhobho enodonga olucekethekileyo ngokusika umbhobho ngobude kwaye ujonge udonga lombhobho ngedayamitha yangaphakathi kunobubanzi obungaphandle.
Ukuodola imibhobho kufana nokuya kumthengisi weemoto kunye noku-odola imoto okanye ilori.Ngoku kukho intaphane yokhetho olukhoyo oluvumela abathengi ukuba balungise imoto ngeendlela ezahlukeneyo – imibala yangaphakathi nangaphandle, iipakethe zokulungisa, iinketho zesitayile sangaphandle, ukhetho lwe-powertrain, kunye nenkqubo yeaudio ephantse yalunga njengenkqubo yokonwabisa ekhaya.Ngazo zonke ezi zikhetho, mhlawumbi awusayi kwaneliseka ngemoto esemgangathweni engekho-frills.
Oku kusebenza kwimibhobho yentsimbi.Inamawaka eenketho okanye iinkcukacha.Ukongeza kwimilinganiselo, inkcazo ikhankanya iipropathi zekhemikhali kunye neepropathi ezininzi zoomatshini ezinje ngamandla esivuno esincinci (MYS), amandla okuqina okugqibela (UTS), kunye nobude obuncinci bokusilela.Noko ke, abaninzi kolu shishino—iinjineli, abathengisi nabenzi—basebenzisa isishunqulelo seshishini baze babize imibhobho “elula” edityanisiweyo baze badwelise uphawu olunye kuphela: ukuqina.
Zama uku-odola imoto ngokwempawu enye ("Ndifuna imoto ene-automatic transmission"), kwaye kunye nomthengisi awuyi kude.Kufuneka agcwalise ifom enokhetho oluninzi.Oku kunjalo ngeepayipi zensimbi: ukuze ufumane umbhobho ofanelekileyo kwisicelo, umenzi wombhobho udinga ulwazi oluninzi kunobunzima.
Kwenzeka njani ukuba ubulukhuni bube yinto eyamkelekileyo endaweni yezinye iimpawu zomatshini?Mhlawumbi yaqala ngabavelisi bemibhobho.Ngenxa yokuba uvavanyo lobulukhuni lukhawuleza, lulula, kwaye lufuna izixhobo ezingabizi kangako, abathengisi bemibhobho bahlala besebenzisa uvavanyo lobulukhuni ukuthelekisa iindidi ezimbini zemibhobho.Ekuphela kwento abayidingayo ukwenza uvavanyo lobulukhuni sisiqhekeza esigudileyo sombhobho kunye nesixhobo sovavanyo.
Ukuqina kombhobho kunxulumene ngokusondeleyo ne-UTS kunye nomgaqo wesithupha (ipesenti okanye uluhlu lwepesenti) luluncedo ekuqikeleleni i-MYS, ngoko kulula ukubona ukuba uvavanyo lobunzima lunokuba ngummeleli ofanelekileyo kwezinye iipropati.
Ukongezelela, ezinye iimvavanyo zinzima ngokwentelekiso.Ngelixa uvavanyo lobulukhuni luthatha kuphela malunga nomzuzu kumatshini omnye, i-MYS, i-UTS kunye novavanyo lolwandiso lufuna ukulungiswa kwesampulu kunye notyalo-mali olubalulekileyo kwisixhobo esikhulu sebhubhoratri.Xa kuthelekiswa, umsebenzi wokusila umbhobho ugqiba uvavanyo lobulukhuni ngemizuzwana, ngelixa ingcali ye-metallurgist yenza uvavanyo lwe-tensile kwiiyure ezimbalwa.Ukwenza uvavanyo lobunzima akunzima.
Oku akuthethi ukuba abavelisi bemibhobho yobunjineli abasebenzisi iimvavanyo zobulukhuni.Kukhuselekile ukuthi uninzi luyakwenza oku, kodwa njengoko bevavanya ukuphindaphindwa kwesixhobo kunye nokuveliswa kwakhona kuzo zonke izixhobo zovavanyo, bayazi kakuhle imida yovavanyo.Uninzi lwabo luyisebenzisela ukuvavanya ubunzima bombhobho njengenxalenye yenkqubo yokuvelisa, kodwa ungayisebenzisi ukulinganisa iipropati zombhobho.Luvavanyo nje lokupasa/ukungaphumeleli.
Kutheni kufuneka ndazi i-MYS, i-UTS kunye nobude obuncinci?Babonisa ukusebenza kwendibano yetyhubhu.
I-MYS ngamandla amancinci abangela ukuguqulwa okusisigxina kwezinto.Ukuba uzama ukugoba kancinane isiqwenga socingo (njenge-hanger) kwaye ukhulule uxinzelelo, enye yezinto ezimbini iya kwenzeka: iya kubuyela kwimeko yayo yangaphambili (ithe tye) okanye ihlale igobile.Ukuba isathe tye, awukagqibi ngaphaya kwe-MYS okwangoku.Ukuba isagobile, uphosile.
Ngoku bamba zombini iziphelo zocingo ngeepliers.Ukuba unokwaphula ucingo phakathi, wenze ukuba udlule kwi-UTS.Uyitsala nzima kwaye unamaqhekeza amabini ocingo ukubonisa imizamo yakho yamandla angaphezu kwawomntu.Ukuba ubude bokuqala bocingo lwaluyi-intshi ezi-5, kwaye ubude obubini emva kokungaphumeleli bongeza ukuya kwi-intshi ezi-6, ucingo luya kunweba i-intshi eyi-1, okanye i-20%.Iimvavanyo ze-tensile zangempela zilinganiswa ngaphakathi kwee-intshi ezi-2 zendawo yokuphumla, kodwa kungakhathaliseki ukuba yintoni - ingcamango yoxinzelelo lomgca ibonisa i-UTS.
Iisampuli ze-Steel micrograph kufuneka zisikwe, zikhazimliswe, kwaye zifakwe ngesisombululo esibuthathaka esincinci (ngokuqhelekileyo i-nitric acid kunye notywala) ukwenza iinkozo zibonakale.Ukwandiswa kwe-100x ngokuqhelekileyo kusetyenziselwa ukuhlola iinkozo zensimbi kunye nokumisela ubungakanani bazo.
Ukuqina luvavanyo lwendlela izinto ezisabela ngayo kwimpembelelo.Khawucinge ukuba ubude obufutshane betyhubhu bubekwe kwi-vise enemihlathi edibeneyo kwaye ishukunyiswe ukuvala i-vise.Ukongeza ukulungelelanisa umbhobho, i-vise jaws ishiya i-imprint ebusweni bombhobho.
Le yindlela olusebenza ngayo uvavanyo lobunzima, kodwa alukho rhabaxa.Uvavanyo lunobungakanani bempembelelo elawulwayo kunye noxinzelelo olulawulwayo.La mandla aguqula umphezulu, enze i-indent okanye i-indentation.Ubungakanani okanye ubunzulu be-dent bumisela ukuqina kwesinyithi.
Xa kuvavanywa intsimbi, iBrinell, iVickers kunye novavanyo lobulukhuni beRockwell ziqhele ukusetyenziswa.Ngamnye unomlinganiselo wakhe, kwaye ezinye zazo zineendlela ezininzi zokuvavanya ezifana ne-Rockwell A, B, C, njl. Kwimibhobho yentsimbi, i-ASTM A513 inkcazo ibhekisela kuvavanyo lwe-Rockwell B (efinyeziweyo njenge-HRB okanye i-RB).Uvavanyo lwe-Rockwell B lulinganisa umahluko kumandla okungena we-1⁄16 intshi ubukhulu bebhola yentsimbi ibe yintsimbi phakathi kokulayishwa kwangaphambili okukhanyayo kunye nomthwalo osisiseko we-100 kgf.Iziphumo eziqhelekileyo zentsimbi eqhelekileyo ethambileyo yiHRB 60.
Izazinzulu zeMathiriyeli ziyazi ukuba ubulukhuni bunobudlelwane bomgca kunye ne-UTS.Ke ngoko, ubunzima obunikiweyo buqikelela i-UTS.Ngokufanayo, umenzi wombhobho uyazi ukuba i-MYS kunye ne-UTS zihlobene.Kwimibhobho edityanisiweyo, i-MYS ikholisa ukuba ngama-70% ukuya kuma-85% e-UTS.Isixa esichanekileyo sixhomekeke kwinkqubo yokuvelisa ityhubhu.Ukuqina kwe-HRB 60 ihambelana ne-UTS 60,000 pounds per square intshi (PSI) kwaye malunga ne-80% MYS, eyi-48,000 PSI.
Ukuchazwa kombhobho oqhelekileyo kwimveliso jikelele bubunzima obukhulu.Ukongeza kubukhulu, iinjineli zikwanomdla ekuchazeni imibhobho yokumelana ne-welded (ERW) ngaphakathi koluhlu olufanelekileyo lokusebenza, olunokubangela ukuba inxalenye yemizobo ibe nobunzima obukhulu obunokwenzeka be-HRB 60. Esi sigqibo sodwa siphumela kwinani leempawu zokuphela komatshini, kuquka nobulukhuni ngokwayo.
Okokuqala, ukuqina kwe-HRB 60 ayisixeleli kakhulu.Ukufundwa kwe-HRB 60 linani elingenamlinganiselo.Izinto ezilinganiswe kwi-HRB 59 zithambile kunezo zivavanywe kwi-HRB 60, kwaye i-HRB 61 inzima kune-HRB 60, kodwa kangakanani?Ayinakubalwa njengomthamo (ulinganiswa ngeedecibels), itorque (elinganiswa ngeepandi-zinyawo), isantya (silinganiswa ngomgama xa kuthelekiswa nexesha), okanye i-UTS (ilinganiselwa ngeeponti nge-intshi yesikwere).Ukufunda iHRB 60 akusixeleli nto ithile.Yimpahla ebonakalayo, kungekhona into ebonakalayo.Okwesibini, ukuzimisela kobulukhuni ngokwako akufanelanga kakuhle ukuqinisekisa ukuphinda-phinda okanye ukuveliswa kwakhona.Uvavanyo lweendawo ezimbini kwisampulu, nokuba iindawo zovavanyo zisondelelene, zihlala zikhokelela ekufundweni kobunzima okwahluke kakhulu.Ubume beemvavanyo buyenza mandundu le ngxaki.Emva komlinganiselo wesikhundla esinye, umlinganiselo wesibini awunakuthatyathwa ukujonga umphumo.Uvavanyo oluphindayo alunakwenzeka.
Oku akuthethi ukuba ukuqina kobunzima akuncedi.Ngokwenyani, esi sisikhokelo esilungileyo kwizinto ze-UTS, kwaye luvavanyo olukhawulezayo nolulula.Nangona kunjalo, nabani na obandakanyekayo kwinkcazo, ekuthengeni, nasekuvelisweni kweetyhubhu kufuneka aqonde imida yabo njengeparamitha yovavanyo.
Ngenxa yokuba umbhobho "oqhelekileyo" awuchazwanga ngokucacileyo, abavelisi bemibhobho ngokuqhelekileyo bayayinciphisa kwiintlobo ezimbini eziqhelekileyo zentsimbi kunye nombhobho njengoko kuchazwe kwi-ASTM A513: 1008 kunye ne-1010 xa kufanelekile.Nangona emva kokungabandakanyi zonke ezinye iintlobo zemibhobho, amathuba okuba neempawu zomatshini ezi ntlobo zimbini zemibhobho zihlala zivulekile.Enyanisweni, ezi ntlobo zemibhobho zinoluhlu olubanzi kakhulu lweempawu zemishini yazo zonke iintlobo zemibhobho.
Ngokomzekelo, ityhubhu ithathwa njengento ethambileyo ukuba i-MYS iphantsi kwaye i-elongation iphezulu, oku kuthetha ukuba yenza ngcono ngokubhekiselele kwi-stretch, deformation, kunye ne-deformation esisigxina kunetyhubhu echazwe njenge-rigid, ene-MYS ephezulu kunye ne-elongation ephantsi. ..Oku kuyafana nomahluko phakathi kocingo oluthambileyo kunye nocingo oluqinileyo olufana nezixhobo zokuxhoma iimpahla kunye needrili.
Ukwandiswa ngokwako yenye into enempembelelo ebalulekileyo kwizicelo zemibhobho ebalulekileyo.Imibhobho yobude obuphakamileyo inokumelana nokuzolula;Izixhobo zobude obuphantsi ziba brittle kwaye ke ngoko zisengozini yokungaphumeleli kokudinwa.Nangona kunjalo, ulwandiso alunxulumananga ngokuthe ngqo ne-UTS, eyipropathi yomatshini kuphela enxulumene ngqo nobunzima.
Kutheni le nto imibhobho ihluka kakhulu kwiimpawu zabo zomatshini?Okokuqala, ukubunjwa kweekhemikhali kuyahluka.Isinyithi sisisombululo esiqinileyo sentsimbi kunye nekhabhoni, kunye nezinye i-alloys ezibalulekileyo.Ukwenza lula, siya kujongana kuphela nepesenti yekhabhoni.Iiathom zekhabhoni zithatha indawo yeeathom zentsimbi, zenza ubume bekristale bentsimbi.I-ASTM 1008 libakala eliphambili elibanzi elinomxholo wekhabhoni ukusuka kwi-0% ukuya kwi-0.10%.I-Zero yinani elikhethekileyo elibonelela ngeempawu ezizodwa kwi-ultra-low carbon content kwintsimbi.I-ASTM 1010 ichaza umxholo wekhabhoni ukusuka kwi-0.08% ukuya kwi-0.13%.Lo mahluko awubonakali mkhulu, kodwa wanele ukwenza umahluko omkhulu kwenye indawo.
Okwesibini, imibhobho yentsimbi inokwenziwa okanye iveliswe kwaye emva koko iqhutywe kwiinkqubo ezisixhenxe ezahlukeneyo zokuvelisa.I-ASTM A513 malunga nokuveliswa kwemibhobho ye-ERW idwelisa iindidi ezisixhenxe:
Ukuba ukubunjwa kweekhemikhali zetsimbi kunye nezigaba zokwenziwa kombhobho akuchaphazeli ubunzima bensimbi, ngoko yintoni?Impendulo yalo mbuzo ithetha ukufundisisa ngenyameko iinkcukacha.Lo mbuzo ukhokelela kweminye imibuzo emibini: zeziphi iinkcukacha kwaye zisondele kangakanani?
Ulwazi oluneenkcukacha malunga neenkozo ezenza intsimbi yimpendulo yokuqala.Xa intsimbi iveliswa kwindawo yokusila yokuqala, ayipholi ibe bubunzima obukhulu ngepropathi enye.Njengoko intsimbi iphola, iimolekyuli zayo zenza iipateni eziphinda-phindayo (iikristale), ezifana nendlela amahlwantsi ekhephu enza ngayo.Emva kokubunjwa kweekristale, zidibene zibe ngamaqela abizwa ngokuba ziinkozo.Njengoko iinkozo zipholile, ziyakhula, zenze iphepha okanye ipleyiti yonke.Ukukhula okuziinkozo kuyeka xa imolekyuli yokugqibela yentsimbi ifunxwa lukhozo.Konke oku kwenzeka kwinqanaba le-microscopic, kunye nengqolowa yentsimbi ephakathi malunga ne-64 microns okanye i-intshi ye-0.0025 ububanzi.Ngelixa ingqolowa nganye ifana nelandelayo, ayifani.Bahluke kancinane omnye komnye ngobukhulu, ukuqhelaniswa, kunye nomxholo wekhabhoni.Unxulumano phakathi kweenkozo kuthiwa yimida yeenkozo.Xa intsimbi ingaphumeleli, umzekelo ngenxa yokudinwa kukuqhekeka, idla ngokungaphumeleli kwimida yengqolowa.
Kufuneka ujonge kufutshane kangakanani ukuze ubone amasuntswana ahlukileyo?Ukwandiswa kwamaxesha e-100 okanye amaxesha angama-100 ukubonwa kweliso lomntu kwanele.Nangona kunjalo, ukujonga nje intsimbi ekrwada kumandla we-100 ayenzi nto ingako.Iisampulu zilungiswa ngokupolisha isampuli kunye etching umphezulu nge-asidi, ngokuqhelekileyo asidi nitric kunye notywala, nto leyo ebizwa nitric acid etching.
Ziziinkozo kunye ne-lattice yazo yangaphakathi emisela amandla empembelelo, i-MYS, i-UTS, kunye nobude obunokuthi intsimbi ikwazi ukumelana ngaphambi kokungaphumeleli.
Amanyathelo okwenza isinyithi afana noxinzelelo olushushu kunye nolubandayo lokuqengqeleka kwisakhiwo seenkozo;ukuba bahlala betshintsha imilo, oku kuthetha ukuba uxinzelelo luye lwakhubaza iinkozo.Amanye amanyathelo okucubungula afana nokujija intsimbi kwiikhoyili, ukukhulula kunye nokudlula kwi-tube yokusila (ukwenza ityhubhu kunye nobukhulu) kuguqula iinkozo zetsimbi.Umzobo obandayo wombhobho kwi-mandrel uphinde ugxininise izinto, njengoko kwenza amanyathelo okuvelisa afana nesiphelo sokubumba kunye nokugoba.Utshintsho kwisakhiwo sengqolowa kuthiwa yi-dislocations.
La manyathelo angasentla achitha i-ductility yensimbi, ukukwazi ukumelana noxinzelelo (ukukrazula) uxinzelelo.Intsimbi iba brittle, nto leyo ethetha ukuba kunokwenzeka ukuba ukuphuka xa uqhubeka ukusebenza ngentsimbi.I-elongation yinto enye yeplastiki (i-compressibility enye).Kubalulekile ukuqonda apha ukuba ukungaphumeleli kaninzi kwenzeka kwingcinezelo, kwaye kungekhona kuxinzelelo.Intsimbi iyakwazi ukumelana noxinzelelo ngenxa yobude bayo obuphezulu.Nangona kunjalo, intsimbi iguquka ngokulula phantsi koxinzelelo olucinezelayo-iyathambile-nto leyo iluncedo.
Thelekisa oku kunye nekhonkrithi, enamandla acinezelayo aphezulu kakhulu kodwa i-ductility ephantsi.Ezi mpawu zichasene nentsimbi.Yiyo loo nto ikhonkrithi esetyenziselwa iindlela, izakhiwo kunye neepavumente zihlala ziqiniswa.Isiphumo sisiphumo esinamandla kuzo zombini izixhobo: intsimbi yomelele kuxinzelelo kwaye ikhonkrithi yomelele ekucinezeleni.
Ngexesha lokuqina, i-ductility yensimbi iyancipha, kwaye ubunzima bayo buyanda.Ngamanye amazwi, iyaqina.Ngokuxhomekeke kwimeko, oku kunokuba luncedo, kodwa kunokuba yinto engathandekiyo, njengoko ubunzima bulingana ne-brittleness.Oko kukuthi, ukuqina kwentsimbi, i-elastic encinci kwaye ngoko ke kunokwenzeka ukuba ingaphumeleli.
Ngamanye amazwi, inyathelo ngalinye lenkqubo lifuna i-ductility yombhobho.Njengoko inxalenye icutshungulwa, iba nzima, kwaye ukuba inzima kakhulu, ngoko ke ngokomgaqo ayinamsebenzi.Ubunzima bububhetyebhetye, kwaye iityhubhu ezibhityileyo ziqhele ukusilela ngexesha lokusetyenziswa.
Ngaba umenzi unazo iinketho kulo mzekelo?Ngamafutshane, ewe.Olu khetho luyi-annealing, kwaye ngelixa ingengomlingo ncam, imalunga nomlingo njengoko kunokubakho.
Ngamagama alula, i-annealing isusa yonke impembelelo yempembelelo yomzimba kwiintsimbi.Kwinkqubo, isinyithi sifudunyezwa ekunciphiseni uxinzelelo okanye ukushisa kwe-recrystallization, okubangela ukukhutshwa kokutshatyalaliswa.Ngaloo ndlela, inkqubo ngokuyinxenye okanye ngokupheleleyo ibuyisela i-ductility, kuxhomekeke kwiqondo lobushushu elithile kunye nexesha elisetyenziswe kwinkqubo yokufunxa.
Ukupholisa i-aneal kunye nokulawulwayo kukhuthaza ukukhula kweenkozo.Oku kunenzuzo ukuba injongo kukunciphisa i-brittleness yezinto eziphathekayo, kodwa ukukhula okuziinkozo okungalawulekiyo kunokuthambisa isinyithi kakhulu, kusenze singasebenziseki ekusetyenzisweni kwayo.Ukumisa inkqubo yokufunxa yenye into ephantse ibe ngumlingo.Ukucima kwiqondo lokushisa elifanelekileyo kunye ne-ejenti yokuqina echanekileyo ngexesha elifanelekileyo liyeka ngokukhawuleza inkqubo kwaye libuyisele iimpawu zentsimbi.
Ngaba kufuneka siyilahle imilinganiselo yobunzima?Hayi.Iimpawu zobunzima zibalulekile, okokuqala, njengesikhokelo ekunqumeni iimpawu zemibhobho yensimbi.Ukuqina ngumlinganiselo oluncedo kunye nenye yeepropathi ezininzi ekufuneka zichazwe xa uodola imathiriyeli ye-tubula kwaye ikhangelwe xa ifunyenwe (ibhalwe ngokuthunyelwa ngakunye).Xa uvavanyo lobulukhuni lusetyenziswa njengomgangatho wovavanyo, kufuneka lube nemilinganiselo efanelekileyo yesikali kunye nemida yolawulo.
Nangona kunjalo, olu alulo uvavanyo lokwenyani lokupasa (ukwamkelwa okanye ukwaliwa) kwezinto.Ukongeza kubulukhuni, abavelisi kufuneka bajonge ukuthunyelwa kumaxesha ngamaxesha ukujonga ezinye iipropati ezifanelekileyo ezifana ne-MYS, i-UTS, okanye ubude obuncinci, ngokuxhomekeke kwisicelo sombhobho.
Wynn H. Kearns is responsible for regional sales for Indiana Tube Corp., 2100 Lexington Road, Evansville, IN 47720, 812-424-9028, wkearns@indianatube.com, www.indianatube.com.
I-Tube & Pipe Journal yasungulwa ngo-1990 njengemagazini yokuqala enikezelwe kushishino lwemibhobho yesinyithi.Namhlanje, isele ikuphela kwempapasho yoshishino kuMntla Melika kwaye iye yaba ngowona mthombo uthembekileyo wolwazi lwabasebenzi betyhubhu.
Ufikelelo olupheleleyo lwedijithali kwi-FABRICATOR ngoku iyafumaneka, inika ufikelelo olulula kwimithombo yoshishino oluxabisekileyo.
Ufikelelo olupheleleyo lwedijithali kwi-Tube & Pipe Journal iyafumaneka ngoku, ibonelela ngokufikelela ngokulula kwizixhobo ezixabisekileyo zeshishini.
Yonwabela ufikelelo olupheleleyo lwedijithali kwi-STAMPING Journal, ijenali yemarike yestamping yesinyithi enenkqubela phambili yetekhnoloji yamva nje, ezona zenzo zibalaseleyo kunye neendaba zeshishini.
Ukufikelela ngokupheleleyo kwi-Fabricator en Español edition yedijithali ngoku iyafumaneka, inika ufikelelo olulula kwimithombo yoshishino oluxabisekileyo.
Kwinxalenye yesibini yomboniso wethu onamacandelo amabini noAdam Heffner, umnini wevenkile yaseNashville kunye nomseki…
Ixesha lokuposa: Jan-27-2023