Izinqubo zokuhlola ezahlukahlukene (uBrinell, uRockwell, uVickers) zinezinqubo ezithile zephrojekthi evivinywayo. Ukuhlolwa kweRockwell T kufanelekile ukuhlola amashubhu odonga olukhanyayo ngokusika ithubhu ngobude nokuhlola udonga kusukela kububanzi bangaphakathi kunobubanzi bangaphandle.
Uku-oda ipayipi kufana nokuya egaraji lezimoto bese u-oda imoto noma iloli. Namuhla, izinketho eziningi ezitholakalayo zivumela abathengi ukuthi benze ngokwezifiso imoto ngezindlela ezahlukahlukene - imibala yangaphakathi nengaphandle, amaphakheji okuhlobisa angaphakathi, izinketho zesitayela sangaphandle, izinketho ze-powertrain, kanye nesistimu yomsindo ecishe incintisane nesistimu yokuzijabulisa yasekhaya. Uma unikezwe zonke lezi zinketho, ungase unganeliseki ngemoto ejwayelekile, engenazo izinto eziningi.
Amapayipi ensimbi ayilokho kanye. Inezinketho eziningi noma imininingwane. Ngaphezu kobukhulu, imininingwane ibala izakhiwo zamakhemikhali kanye nezindlela eziningana zokwenza izinto njenge-minimum yield strength (MYS), i-ultimate tensile strength (UTS), kanye ne-minimum elongation ngaphambi kokwehluleka. Kodwa-ke, abaningi embonini—onjiniyela, ama-ejenti okuthenga, kanye nabakhiqizi—basebenzisa izindlela ezimfushane zemboni ezamukelekayo ezidinga ukusetshenziswa kwepayipi “elijwayelekile” elihlanganisiwe futhi bachaza isici esisodwa kuphela: ubulukhuni.
Zama uku-oda imoto ngesici esisodwa (“Ngidinga imoto enokudluliselwa okuzenzakalelayo”) futhi ngeke ufike kude kakhulu nomthengisi. Kufanele agcwalise ifomu loku-oda elinezinketho eziningi. Ipayipi linjalo nje – ukuze athole ipayipi elifanele isicelo, umenzi wamapayipi udinga ulwazi olwengeziwe kunokuqina nje.
Ubulukhuni buba kanjani indawo eyaziwayo yezinye izakhiwo zemishini? Cishe kwaqala ngomkhiqizi wamapayipi. Ngenxa yokuthi ukuhlolwa kobulukhuni kuyashesha, kulula, futhi kudinga imishini engabizi kakhulu, abathengisi bamapayipi bavame ukusebenzisa ukuhlolwa kobulukhuni ukuqhathanisa amapayipi amabili. Ukuze benze ukuhlolwa kobulukhuni, abakudingayo nje ubude obubushelelezi bepayipi kanye nesitendi sokuhlola.
Ubulukhuni beshubhu buhambisana kahle ne-UTS, futhi njengomthetho wesithupha, amaphesenti noma ububanzi bephesenti buyasiza ekulinganiseni i-MYS, ngakho-ke kulula ukubona ukuthi ukuhlolwa kobulukhuni kungaba kanjani i-proxy efanelekile kwezinye izakhiwo.
Futhi, ezinye izivivinyo ziyinkimbinkimbi kakhulu. Ngenkathi ukuhlolwa kobulukhuni kuthatha umzuzu owodwa noma ngaphezulu emshinini owodwa, i-MYS, i-UTS kanye nokuhlolwa kobude kudinga ukulungiswa kwesampula kanye nokutshalwa kwezimali okukhulu emishinini emikhulu yelabhorethri. Njengokuqhathanisa, kuthatha imizuzwana embalwa ukuthi umqhubi we-tube mill enze ukuhlolwa kobulukhuni kanye namahora ukuthi uchwepheshe we-metallurgical ochwepheshe enze ukuhlolwa kokubopha. Akunzima ukwenza ukuhlolwa kobulukhuni.
Lokhu akusho ukuthi abakhiqizi bamapayipi anjiniyela abasebenzisi ukuhlolwa kobulukhuni. Kuphephile ukusho ukuthi iningi labantu liyakwenza lokho, kodwa ngenxa yokuthi benza ukuhlolwa kokuphindaphinda kanye nokuphindaphinda kuzo zonke imishini yabo yokuhlola, bayazi kahle imikhawulo yokuhlolwa. Iningi lisebenzisa ukuhlola ubulukhuni bepayipi njengengxenye yenqubo yokukhiqiza, kodwa abalisebenzisi ukulinganisa izakhiwo zepayipi. Lokhu kumane kuwukuhlolwa kokupasa/ukwehluleka.
Kungani udinga ukwazi nge-MYS, i-UTS kanye nobude obuncane? Zibonisa ukuthi ithubhu lizoziphatha kanjani lapho lihlanganiswa.
I-MYS ingamandla amancane abangela ukuguquka okungapheli kwezinto. Uma uzama ukugoba ucingo oluqondile (njenge-hanger yejazi) kancane bese ukhulula ingcindezi, kuzokwenzeka enye yezinto ezimbili: izobuyela esimweni sayo sokuqala (iqonde) noma izohlala igobile. Uma isaqondile, awukadluli i-MYS. Uma isagobile, usuyidlulile.
Manje, sebenzisa ama-pliers ukubopha izinhlangothi zombili zentambo. Uma ungayidabula intambo ibe yizicucu ezimbili, usuyidlulile i-UTS yayo. Ubeka ukucindezeleka okukhulu kuyo futhi unezintambo ezimbili zokubonisa umzamo wakho ongaphezu kwamandla omuntu. Uma ubude bokuqala bentambo bungamasentimitha angu-5, futhi ubude obubili ngemva kokwehluleka bufika kumasentimitha angu-6, intambo yelulwa nge-intshi eli-1, noma u-20%. Ukuhlolwa kobude bangempela kulinganiswa ngaphakathi kwamasentimitha amabili ukusuka endaweni yokwehluleka, kodwa noma ngabe yini - umqondo wentambo yokudonsa ubonisa i-UTS.
Amasampula e-photomicrograph ensimbi adinga ukunqunywa, ukupholishwa, nokuqoshwa kusetshenziswa isisombululo esino-asidi omncane (ngokuvamile i-nitric acid kanye notshwala (i-nitroethanol)) ukuze kubonakale okusanhlamvu. Ukukhulisa okungu-100x kuvame ukusetshenziswa ukuhlola okusanhlamvu kwensimbi nokunquma usayizi wokusanhlamvu.
Ukuqina kuyisilingo sokuthi into ethile isabela kanjani ekushayweni. Cabanga ngokufaka ipayipi elifushane ku-vise enemihlathi egobile bese uphendula i-vise ukuze ivale. Ngaphezu kokwenza ipayipi libe yithambe, imihlathi ye-vise ishiya nezimbobo ebusweni bepayipi.
Yileyo ndlela ukuhlolwa kobulukhuni okusebenza ngayo, kodwa akukubi kangako. Lokhu kuhlolwa kunosayizi womthelela olawulwayo kanye nokucindezela okulawulwayo. Lawa mandla aguqula ubuso, adale ukugoba noma ukugoba. Ubukhulu noma ukujula kokugoba kunquma ubulukhuni bensimbi.
Ukuhlola insimbi, izivivinyo zokuqina ezivamile yiBrinell, Vickers, kanye neRockwell. Ngayinye inesilinganiso sayo, kanti ezinye zinezindlela eziningi zokuhlola, njengeRockwell A, B, kanye ne-C. Kumapayipi ensimbi, i-ASTM Specification A513 ibhekisela ekuhlolweni kweRockwell B (okufingqiwe njenge-HRB noma i-RB). Ukuhlolwa kweRockwell B kulinganisa umehluko ekungeneni kwensimbi ngebhola lensimbi elinobubanzi obuyi-1⁄16-intshi phakathi komthwalo omncane wangaphambi kokulayisha kanye nomthwalo oyinhloko ongu-100 kgf. Umphumela ojwayelekile wensimbi ejwayelekile ethambile yi-HRB 60.
Ososayensi bezinto zokwakha bayazi ukuthi ubulukhuni buhlobene ngokuqondile ne-UTS. Ngakho-ke, ubulukhuni obuthile bungabikezela i-UTS. Ngokufanayo, abakhiqizi bamashubhu bayazi ukuthi i-MYS ne-UTS zihlobene. Kumapayipi ahlanganisiwe, i-MYS ngokuvamile ingu-70% kuya ku-85% we-UTS. Inani eliqondile lincike enkambisweni yokwenza ishubhu. Ubulukhuni be-HRB 60 buhlobene ne-UTS yamaphawundi angu-60,000 nge-intshi yesikwele (i-PSI) kanye ne-MYS engu-80%, noma i-48,000 PSI.
Incazelo yamapayipi evame kakhulu ekukhiqizweni okuvamile ubulukhuni obukhulu. Ngaphezu kobukhulu, unjiniyela wayekhathazekile ngokucacisa ipayipi elihlanganisiwe lokumelana nogesi elihlanganisiwe (i-ERW) ngaphakathi kwebanga elihle lokusebenza, okungaholela ekubeni ubulukhuni obukhulu obungaba yi-HRB 60 butholakale emdwebweni wezingxenye. Lesi sinqumo sodwa siholela ezicini eziningi zokugcina zemishini, okuhlanganisa nobulukhuni uqobo.
Okokuqala, ubulukhuni be-HRB 60 abusitsheli okuningi. Ukufundwa kwe-HRB 60 kuyinombolo engenakulinganiswa. Izinto ezihlolwe nge-HRB 59 zithambile kunezinto ezihlolwe nge-HRB 60, kanti i-HRB 61 inzima kune-HRB 60, kodwa zingaki? Ayikwazi ukulinganiswa njengevolumu (elinganiswa ngama-decibel), i-torque (elinganiswa ngamakhilogremu-izinyawo), ijubane (elilinganiswa ngebanga uma kuqhathaniswa nesikhathi), noma i-UTS (elinganiswa ngamakhilogremu nge-intshi yesikwele). Ukufunda i-HRB 60 akusitsheli lutho oluqondile. Lokhu kuyimpahla yezinto, kodwa akuyona impahla ebonakalayo. Okwesibili, ukuhlolwa kobulukhuni akufaneleki ukuphindaphinda noma ukuphindaphinda. Ukuhlola izindawo ezimbili kusampula yokuhlola, noma ngabe izindawo zokuhlola ziseduze, kuvame ukuholela ekuhlukeni okukhulu kokufundwa kobulukhuni. Ukuhlanganisa le nkinga uhlobo lokuhlolwa. Ngemva kokuba indawo isilinganisiwe, ayikwazi ukulinganiswa okwesibili ukuqinisekisa imiphumela. Ukuphindaphinda kokuhlolwa akunakwenzeka.
Lokhu akusho ukuthi ukuhlolwa kobulukhuni akulungile. Eqinisweni, kunikeza umhlahlandlela omuhle we-UTS yento, futhi kuyindlela esheshayo nelula yokuyenza. Kodwa-ke, wonke umuntu ohilelekile ekuchazeni, ekuthengeni nasekukhiqizeni amashubhu kufanele aqaphele ukulinganiselwa kwawo njengepharamitha yokuhlola.
Ngenxa yokuthi ipayipi "elivamile" alichazwanga kahle, uma kudingeka, abakhiqizi bamapayipi bavame ukulinciphisa libe izinhlobo ezimbili zamapayipi ensimbi asetshenziswa kakhulu kanye namapayipi achazwe ku-ASTM A513: 1008 kanye no-1010. Ngisho nangemva kokuqeda zonke ezinye izinhlobo zamapayipi, amathuba ngokwezakhiwo zemishini zalezi zinhlobo ezimbili zamapayipi avulekile kakhulu. Eqinisweni, lezi zinhlobo zamapayipi zinobubanzi obukhulu bezakhiwo zemishini zanoma yiluphi uhlobo.
Isibonelo, ithubhu ichazwa njengethambile uma i-MYS iphansi futhi ukunwebeka kuphakeme, okusho ukuthi isebenza kangcono ekucindezelweni, ekuphambukeni nasekusethweni kunethubhu echazwe njengeqinile, ene-MYS ephezulu kanye nokunwebeka okuphansi. Lokhu kufana nomehluko phakathi kwentambo ethambile neqinile, njengeziphanyeko zejazi kanye nama-drill.
Ukwelulwa ngokwako kungenye into enomthelela omkhulu ekusetshenzisweni kwamapayipi abalulekile. Amashubhu anokwelulwa okuphezulu angamelana namandla okudonswa; izinto ezinokwelulwa okuphansi ziyaphuka kalula futhi ngenxa yalokho zithambekele kakhulu ekuhlulekeni okuyingozi kohlobo lokukhathala. Kodwa-ke, ukwelulwa akuhlobene ngqo ne-UTS, okuwukuphela kwento yomshini ehlobene ngqo nokuqina.
Kungani izakhiwo zemishini zamashubhu zihluka kangaka? Okokuqala, ukwakheka kwamakhemikhali kuhlukile. Insimbi iyisisombululo esiqinile sensimbi nekhabhoni nezinye izinto ezibalulekile. Ukuze kube lula, sizobhekana namaphesenti ekhabhoni kuphela lapha. Ama-athomu ekhabhoni athatha indawo yama-athomu ensimbi athile, akha isakhiwo sekristalu sensimbi. I-ASTM 1008 iyibanga eliyinhloko elihlanganisa konke elinokuqukethwe kwekhabhoni okungu-0% kuya ku-0.10%. I-Zero iyinombolo ekhethekile kakhulu ekhiqiza izakhiwo ezihlukile lapho okuqukethwe kwekhabhoni ensimbini kuphansi kakhulu. I-ASTM 1010 icacisa okuqukethwe kwekhabhoni phakathi kuka-0.08% no-0.13%. Lo mehluko awubonakali mkhulu ngokwanele ukwenza umehluko omkhulu kwenye indawo.
Okwesibili, ipayipi lensimbi lingakhiwa noma lenziwe bese licutshungulwa ngezinqubo eziyisikhombisa ezahlukene zokukhiqiza. I-ASTM A513 ehlobene nokukhiqizwa kwamapayipi e-ERW ibala izinhlobo eziyisikhombisa:
Uma ukwakheka kwamakhemikhali kwezinyathelo zokukhiqiza insimbi kanye neshubhu kungenawo umthelela ebulukhunini bensimbi, kuyini? Ukuphendula lo mbuzo kusho ukubhekabheka imininingwane. Lo mbuzo ubuza eminye imibuzo emibili: Yimiphi imininingwane, futhi iseduze kangakanani?
Imininingwane mayelana nezinhlamvu ezakha insimbi iyimpendulo yokuqala. Uma insimbi yenziwa emshinini wensimbi oyinhloko, ayipholi ibe yibhulokhi elikhulu elinesici esisodwa. Njengoba insimbi iphola, ama-molecule ensimbi ahlela ngamaphethini aphindaphindayo (amakristalu), afana nendlela ama-snowflake akha ngayo. Ngemva kokwakheka kwamakristalu, ahlangana abe amaqembu abizwa ngokuthi ama-grain. Njengoba ukupholisa kuqhubeka, izinhlamvu ziyakhula futhi zakheke kulo lonke ishidi noma ipuleti. Izinhlamvu ziyayeka ukukhula njengoba ama-molecule ensimbi okugcina emuncwa yizinhlamvu. Konke lokhu kwenzeka ezingeni elincane kakhulu ngoba usayizi ojwayelekile wezinhlamvu zensimbi ungamasentimitha angu-64 noma angu-0.0025 ububanzi. Ngenkathi uhlamvu ngalunye lufana nolulandelayo, alufani. Luyahlukahluka kancane ngobukhulu, ukuma kanye nokuqukethwe kwekhabhoni. Ukuxhumana phakathi kwezinhlamvu kubizwa ngokuthi umngcele wezinhlamvu. Uma insimbi ihluleka, isibonelo ngenxa yokuqhekeka kokukhathala, ivame ukwehluleka eceleni kwemingcele yezinhlamvu.
Kungakanani okufanele ubheke ukuze ubone izinhlamvu ezibonakalayo? Ukukhulisa okuphindwe kayi-100, noma ukubona komuntu okuphindwe kayi-100, kwanele. Kodwa-ke, ukubheka nje insimbi engakaphathwa izikhathi eziyi-100 amandla akuvezi okuningi. Isampula ilungiswa ngokupholisha isampula bese iqopha ubuso nge-asidi (ngokuvamile i-nitric acid kanye notshwala) ebizwa ngokuthi i-nitroethanol etchant.
Yizinhlayiya kanye ne-lattice yazo yangaphakathi enquma amandla omthelela, i-MYS, i-UTS kanye nobude insimbi engabumelana nabo ngaphambi kokuba yehluleke.
Izinyathelo zokwenza insimbi, njengokugoqa okushisayo nokubandayo kwe-strip, zifaka ukucindezeleka esakhiweni sokusanhlamvu; uma zishintsha unomphela isimo, lokhu kusho ukuthi ukucindezeleka kuyawushintsha uhlamvu. Ezinye izinyathelo zokucubungula, njengokugoqa insimbi ibe yizikhoyili, ukuyivula, kanye nokuguqula uhlamvu lwensimbi nge-tube mill (ukwakha nokulinganisa i-tube). Ukudonsa i-tube e-mandrel kubanda kubeka ingcindezi ezintweni, njengoba kwenza nezinyathelo zokwenza ezifana nokugcina ukwakheka nokugoba. Izinguquko esakhiweni sokusanhlamvu zibizwa ngokuthi ama-dislocations.
Izinyathelo ezingenhla zinciphisa ukuqina kwensimbi, okuyikhono layo lokubekezelela ukucindezeleka kokudonsa (ukudonsa-ukuvula). Insimbi iba buthakathaka, okusho ukuthi kungenzeka ukuthi iphuke uma uqhubeka nokusebenza kuyo. Ukuqina kungenye yezingxenye zokuqina (ukuqina kungenye). Kubalulekile ukuqonda ukuthi ukwehluleka kuvame ukwenzeka ngesikhathi sokucindezeleka kokudonsa, hhayi ukucindezela. Insimbi imelana kakhulu nokucindezeleka kokudonsa ngenxa yamandla ayo aphezulu okuphakama. Kodwa-ke, insimbi iguquguquka kalula ngaphansi kokucindezeleka kokucindezela - iyi-ductile - okuyinzuzo.
Ikhonkrithi inamandla okucindezela aphezulu kodwa i-ductility iphansi uma iqhathaniswa nekhonkrithi. Lezi zakhiwo ziphambene nezensimbi. Yingakho ikhonkrithi esetshenziselwa imigwaqo, izakhiwo kanye nezindlela zokuhamba ngezinyawo ivame ukufakwa i-rebar. Umphumela uba umkhiqizo onamandla ezinto ezimbili: ngaphansi kokucindezeleka, insimbi inamandla, kanti ngaphansi kokucindezeleka, ikhonkrithi.
Ngesikhathi sokusebenza ngokubandayo, njengoba ukuqina kwensimbi kuncipha, ubulukhuni bayo buyanda. Ngamanye amazwi, izoqina. Kuye ngesimo, lokhu kungaba yinzuzo; nokho, kungaba yiphutha ngoba ubulukhuni bulinganiswa nokuqhekeka. Okusho ukuthi, njengoba insimbi iba nzima, iba nokunwebeka okuncane; ngakho-ke, kungenzeka kakhulu ukuthi yehluleke.
Ngamanye amazwi, isinyathelo ngasinye senqubo sidla ukuqina kwepayipi. Kuba nzima njengoba ingxenye isebenza, futhi uma ilukhuni kakhulu ayisebenzi. Ukuqina kuwukuphuka, futhi ipayipi eliqhekekile cishe lizohluleka uma lisetshenziswa.
Ingabe umenzi unezinketho kulokhu? Ngamafuphi, yebo. Leyo nketho iyashisa, futhi yize ingeyona imilingo impela, isondele kakhulu kumlingo ngangokunokwenzeka.
Ngokwesimo sabantu abavamile, uku-annealing kususa yonke imiphumela yokucindezeleka ngokomzimba ensimbini. Le nqubo ifudumeza insimbi ibe yi-reliever-stress noma izinga lokushisa lokuphinda i-crystallization, ngaleyo ndlela isuse ukuhlukana. Kuye ngokushisa okuthile nesikhathi esisetshenziswe enkambisweni yoku-annealing, inqubo ngaleyo ndlela ibuyisela ingxenye noma yonke i-ductility yayo.
Ukupholisa okuncibilikisiwe nokulawulwayo kukhuthaza ukukhula kokusanhlamvu. Lokhu kuyazuzisa uma umgomo uwukunciphisa ubuthakathaka bezinto, kodwa ukukhula kokusanhlamvu okungalawulwa kungathambisa insimbi kakhulu, okwenza ingasetshenziswa ngendlela ehlosiwe. Ukumisa inqubo yokuncibilikisa kungenye into ecishe ibe yimilingo. Ukucima ekushiseni okulungile nge-ejenti yokucima efanele ngesikhathi esifanele kuletha inqubo ekumisweni okusheshayo ukuze kutholakale izakhiwo zokubuyisa insimbi.
Ingabe kufanele silahle incazelo yobulukhuni? cha. Izici zobulukhuni zibalulekile ikakhulukazi njengendawo yokubhekisela lapho kucaciswa amapayipi ensimbi. Isilinganiso esiwusizo, ubulukhuni bungenye yezici eziningana okufanele zicaciswe lapho ku-odwa izinto ezishubhu futhi zihlolwe lapho zitholwa (futhi kufanele ziqoshwe ngokuthunyelwa ngakunye). Lapho ukuhlolwa kobulukhuni kuyindinganiso yokuhlola, kufanele kube namanani esikali afanele kanye namabanga okulawula.
Kodwa-ke, akulona ukuhlolwa kwangempela kwezinto ezifanele (ukwamukela noma ukwenqaba). Ngaphezu kobulukhuni, abakhiqizi kufanele bahlole ngezikhathi ezithile ukuthunyelwa ukuze bathole ezinye izakhiwo ezifanele, njenge-MYS, i-UTS, noma ukunwetshwa okuncane, kuye ngokusetshenziswa kwepayipi.
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 yaba umagazini wokuqala ozinikele ekukhonzeni imboni yamapayipi ensimbi ngo-1990. Namuhla, isalokhu iyincwadi kuphela eNyakatho Melika ezinikele embonini futhi isibe umthombo wolwazi othembekile kakhulu kochwepheshe bamapayipi.
Manje ngokufinyelela okugcwele kuhlelo lwedijithali lwe-FABRICATOR, ukufinyelela okulula ezinsizeni ezibalulekile zemboni.
Uhlelo lwedijithali lwe-The Tube & Pipe Journal seluyatholakala ngokugcwele manje, lunikeza ukufinyelela okulula ezinsizeni ezibalulekile zemboni.
Jabulela ukufinyelela okugcwele kuhlelo lwedijithali lwe-STAMPING Journal, oluhlinzeka ngentuthuko yakamuva kwezobuchwepheshe, imikhuba emihle kanye nezindaba zemboni zemakethe yokunyathela insimbi.
Jabulela ukufinyelela okugcwele kuhlelo lwedijithali lwe-Additive Report ukuze ufunde ukuthi ukukhiqiza okwengeziwe kungasetshenziswa kanjani ukuthuthukisa ukusebenza kahle nokwandisa inzuzo.
Manje ngokufinyelela okugcwele kuhlelo lwedijithali lwe-The Fabricator ngesi-Español, ukufinyelela okulula ezinsizeni ezibalulekile zemboni.