Ma protocol osiyanasiyana oyesera (Brinell, Rockwell, Vickers) ali ndi njira zomwe zimagwirizana ndi polojekiti yomwe ikuyesedwa. Mayeso a Rockwell T ndi oyenera kuyang'ana machubu opepuka a khoma mwa kudula chubucho kutalika kwake ndikuyesa khoma kuchokera m'mimba mwake wamkati osati m'mimba mwake wakunja.
Kuyitanitsa chubu cha matailosi kuli ngati kupita ku malo ogulitsa magalimoto ndikuyitanitsa galimoto kapena galimoto yayikulu. Masiku ano, njira zambiri zomwe zilipo zimathandiza ogula kusintha galimotoyo m'njira zosiyanasiyana - mitundu yamkati ndi yakunja, mapaketi okongoletsa mkati, njira zokongoletsa kunja, njira zoyendetsera magetsi, ndi makina amawu omwe amafanana ndi njira yosangalalira kunyumba. Popeza pali njira zonsezi, simungakhutire ndi galimoto yokhazikika, yopanda mavuto.
Mapaipi achitsulo ndi amenewo basi. Ali ndi zosankha zambiri kapena ma specification. Kuphatikiza pa miyeso, ma specification amalemba zinthu za mankhwala ndi ma mechanical monga minimum yield strength (MYS), ultimate tensile strength (UTS), ndi minimum elongation isanagwe. Komabe, ambiri mumakampani—mainjiniya, ogulitsa, ndi opanga—amagwiritsa ntchito ma shorthand ovomerezeka amakampani omwe amafunikira kugwiritsa ntchito chitoliro “chabwinobwino” cholumikizidwa ndipo amatchula khalidwe limodzi lokha: kuuma.
Yesani kuyitanitsa galimoto ndi chizindikiro chimodzi ("Ndikufuna galimoto yokhala ndi automatic transmission") ndipo simudzapita patali ndi wogulitsa. Ayenera kudzaza fomu yoyitanitsa yokhala ndi zosankha zambiri. Chitoliro ndi chimenecho - kuti apeze chitoliro choyenera kugwiritsa ntchito, wopanga chitoliro amafunika zambiri osati kuuma kokha.
Kodi kuuma kumakhala bwanji m'malo mwa zinthu zina zamakina? Mwina kunayamba ndi wopanga mapaipi. Popeza kuyesa kuuma n'kwachangu, kosavuta, ndipo kumafuna zida zotsika mtengo, ogulitsa machubu nthawi zambiri amagwiritsa ntchito kuyesa kuuma poyerekeza machubu awiri. Kuti achite mayeso ouma, chomwe amafunikira ndi kutalika kosalala kwa chitoliro ndi choyimilira choyesera.
Kuuma kwa chubu kumagwirizana bwino ndi UTS, ndipo monga lamulo, kuchuluka kwa maperesenti kapena kuchuluka kwa maperesenti kumathandiza poyesa MYS, kotero n'zosavuta kuona momwe kuyesa kuuma kungakhale koyenera pa zinthu zina.
Komanso, mayeso ena ndi ovuta kwambiri. Ngakhale kuyesa kuuma kumatenga mphindi imodzi yokha kapena kuposerapo pa makina amodzi, MYS, UTS ndi kuyesa kutalika kumafuna kukonzekera zitsanzo ndi kuyika ndalama zambiri mu zida zazikulu za labotale. Poyerekeza, zimatenga masekondi kuti woyendetsa chubu achite mayeso a kuuma ndipo nthawi zina katswiri wa zitsulo amachita mayeso omangika. Sikovuta kuchita mayeso a kuuma.
Izi sizikutanthauza kuti opanga mapaipi opangidwa mwaluso sagwiritsa ntchito mayeso okhwima. Ndikoyenera kunena kuti anthu ambiri amachita, koma chifukwa amachita mayeso obwerezabwereza komanso obwerezabwereza pazida zawo zonse zoyesera, amadziwa bwino zofooka za mayesowo. Ambiri amagwiritsa ntchito mayeso okhwima ngati gawo la njira yopangira, koma sagwiritsa ntchito kuyeza mphamvu ya mapaipi. Imeneyi ndi mayeso ongopambana/olephera.
N’chifukwa chiyani muyenera kudziwa za MYS, UTS ndi kutalika kochepa? Zimasonyeza momwe chubucho chidzakhalire mukamachisonkhanitsa.
MYS ndi mphamvu yochepa kwambiri yomwe imayambitsa kusintha kosatha kwa zinthuzo. Ngati muyesa kupinda waya wowongoka (monga chopachikira malaya) pang'ono ndikutulutsa mphamvu, chimodzi mwa zinthu ziwiri chidzachitika: chidzabwerera momwe chinalili poyamba (chowongoka) kapena chidzapitirirabe kupindika. Ngati chikadali chowongoka, simunadutse MYS. Ngati chikadali chopindika, mwachipitirira.
Tsopano, gwiritsani ntchito zopukutira kuti mutseke malekezero onse a waya. Ngati mungathe kung'amba wayawo m'zigawo ziwiri, ndiye kuti mwapitirira UTS yake. Mumaika mphamvu zambiri pa iyo ndipo muli ndi mawaya awiri osonyeza khama lanu lapamwamba. Ngati kutalika koyambirira kwa wayawo ndi mainchesi 5, ndipo kutalika kuwiri pambuyo pa kulephera kumawonjezeka kufika mainchesi 6, wayawo umatambasulidwa ndi inchi imodzi, kapena 20%. Kuyesa kwenikweni kwa kutalika kumayesedwa mkati mwa mainchesi awiri kuchokera pamene kulephera, koma mulimonse momwe zingakhalire - lingaliro la waya wokoka likuwonetsa UTS.
Zitsanzo za chitsulo chojambulidwa ndi zithunzi ziyenera kudulidwa, kupukutidwa, ndikudulidwa pogwiritsa ntchito yankho la asidi pang'ono (nthawi zambiri nitric acid ndi mowa (nitroethanol)) kuti tinthu tating'onoting'ono tiwonekere. Kukula kwa 100x nthawi zambiri kumagwiritsidwa ntchito poyang'ana tinthu tachitsulo ndikuzindikira kukula kwa tinthu tating'onoting'ono.
Kuuma ndi njira yoyesera momwe chinthu chimayankhira chikakhudzidwa. Tangoganizirani kuyika chitoliro chachifupi mu vinise yokhala ndi nsagwada zopindika ndikutembenuza vinise kuti itseke. Kuwonjezera pa kupyapyala kwa payipi, nsagwada za vinise zimasiyanso mabowo pamwamba pa payipi.
Umu ndi momwe mayeso a kuuma amagwirira ntchito, koma si ovuta kwambiri. Mayesowa ali ndi kukula kolamulidwa kwa kukhudzidwa ndi kupanikizika kolamulidwa. Mphamvu izi zimasokoneza pamwamba, ndikupanga kupindika kapena kupindika. Kukula kapena kuzama kwa kupindika kumatsimikizira kuuma kwa chitsulocho.
Poyesa chitsulo, mayeso odziwika bwino a kuuma ndi Brinell, Vickers, ndi Rockwell. Chilichonse chili ndi sikelo yakeyake, ndipo china chili ndi njira zingapo zoyesera, monga Rockwell A, B, ndi C. Pa mapaipi achitsulo, ASTM Specification A513 imatchula mayeso a Rockwell B (ofupikitsidwa ngati HRB kapena RB). Mayeso a Rockwell B amayesa kusiyana kwa kulowa kwa chitsulo ndi mpira wachitsulo wa mainchesi 1⁄16 pakati pa katundu wocheperako ndi katundu woyamba wa 100 kgf. Zotsatira zodziwika bwino za chitsulo chofatsa chokhazikika ndi HRB 60.
Asayansi a zinthu amadziwa kuti kuuma kumayenderana ndi UTS. Chifukwa chake, kuuma kwina kumatha kulosera UTS. Momwemonso, opanga machubu amadziwa kuti MYS ndi UTS ndi ofanana. Pa chitoliro cholumikizidwa, MYS nthawi zambiri imakhala 70% mpaka 85% ya UTS. Kuchuluka kwenikweni kumadalira njira yopangira chubu. Kuuma kwa HRB 60 kumagwirizana ndi UTS ya mapaundi 60,000 pa inchi imodzi (PSI) ndi MYS ya 80%, kapena 48,000 PSI.
Chida chodziwika bwino cha mapaipi popanga zinthu zambiri ndi kuuma kwakukulu. Kuphatikiza pa kukula, mainjiniya anali ndi nkhawa yosankha chitoliro cholimba chamagetsi cholimba (ERW) chomwe chili mkati mwa malo abwino ogwirira ntchito, zomwe zingapangitse kuti kuuma kwakukulu kwa HRB 60 kupezeke pa chojambula cha zigawo. Kusankha kumeneku kokha kumabweretsa mitundu yosiyanasiyana ya zinthu zamakina, kuphatikizapo kuuma kokha.
Choyamba, kuuma kwa HRB 60 sikutiuza zambiri. Kuwerenga kwa HRB 60 ndi nambala yopanda muyeso. Zinthu zomwe zayesedwa ndi HRB 59 ndi zofewa kuposa zomwe zayesedwa ndi HRB 60, ndipo HRB 61 ndi yovuta kuposa HRB 60, koma ndi kuchuluka kotani? Sizingayesedwe monga voliyumu (yoyesedwa mu ma decibel), torque (yoyesedwa mu mapaundi-feet), liwiro (yoyesedwa mtunda poyerekeza ndi nthawi), kapena UTS (yoyesedwa mu mapaundi pa inchi imodzi). Kuwerenga HRB 60 sikutiuza chilichonse chapadera. Ichi ndi chizindikiro cha chinthucho, koma si chizindikiro chenicheni. Chachiwiri, kuyesa kuuma sikoyenera kubwerezabwereza kapena kubwerezabwereza. Kuyesa malo awiri pa chitsanzo choyesera, ngakhale malo oyesera ali pafupi, nthawi zambiri kumabweretsa kusiyana kwakukulu kwa kuuma. Kuonjezera vutoli ndi mtundu wa mayeso. Malo atayesedwa, sangathe kuyezedwa kachiwiri kuti atsimikizire zotsatira. Kubwerezabwereza kwa mayeso sikungatheke.
Izi sizikutanthauza kuti kuyesa kuuma ndikovuta. Ndipotu, kumapereka chitsogozo chabwino cha UTS ya chinthucho, ndipo ndi mayeso achangu komanso osavuta kuchita. Komabe, aliyense amene akugwira ntchito yosankha, kugula ndi kupanga machubu ayenera kudziwa zofooka zake ngati gawo loyesera.
Popeza chitoliro "chabwinobwino" sichimafotokozedwa bwino, pakafunika kutero, opanga mapaipi nthawi zambiri amachichepetsa mpaka mitundu iwiri ya mapaipi achitsulo ndi mapaipi omwe amagwiritsidwa ntchito kwambiri omwe afotokozedwa mu ASTM A513: 1008 ndi 1010. Ngakhale atachotsa mitundu ina yonse ya machubu, mwayi wokhudzana ndi mphamvu zamakina za mitundu iwiriyi ya machubu ndi wotseguka kwambiri. Ndipotu, mitundu iyi ya machubu ili ndi mphamvu zambiri zamakina zamtundu uliwonse.
Mwachitsanzo, chubu chimafotokozedwa ngati chofewa ngati MYS ili yotsika ndipo kutalika kwake kuli kwakukulu, zomwe zikutanthauza kuti chimagwira ntchito bwino kwambiri pakukoka, kupotoka ndi kukhazikika kuposa chubu chomwe chimafotokozedwa ngati cholimba, chomwe chili ndi MYS yapamwamba komanso kutalika kochepa. Izi zikufanana ndi kusiyana pakati pa waya wofewa ndi wolimba, monga zopachikira ndi zobowolera.
Kutalikirana kokha ndi chinthu china chomwe chimakhudza kwambiri ntchito zofunika kwambiri za mapaipi. Machubu okhala ndi kutalika kwakukulu amatha kupirira mphamvu zomangika; zipangizo zokhala ndi kutalika kochepa zimakhala zofooka kwambiri motero zimakhala zosavuta kulephera kutopa kwambiri. Komabe, kutalika sikukhudzana mwachindunji ndi UTS, yomwe ndi mphamvu yokhayo yamakina yokhudzana mwachindunji ndi kuuma.
Chifukwa chiyani mawonekedwe a makina a machubu amasiyana kwambiri? Choyamba, kapangidwe ka mankhwala ndi kosiyana. Chitsulo ndi yankho lolimba la chitsulo ndi kaboni ndi zinthu zina zofunika. Kuti tipeze mosavuta, tidzangoyang'ana kuchuluka kwa kaboni pano. Maatomu a kaboni amalowa m'malo mwa maatomu ena achitsulo, ndikupanga kapangidwe ka kristalo ka chitsulo. ASTM 1008 ndi mtundu woyambira wokhala ndi kuchuluka kwa kaboni kuyambira 0% mpaka 0.10%. Zero ndi nambala yapadera kwambiri yomwe imapanga mawonekedwe apadera pamene kuchuluka kwa kaboni muchitsulo kuli kotsika kwambiri. ASTM 1010 imatchula kuchuluka kwa kaboni pakati pa 0.08% ndi 0.13%. Kusiyana kumeneku sikukuwoneka kwakukulu, koma ndi kwakukulu mokwanira kuti kupange kusiyana kwakukulu kwina.
Chachiwiri, chitoliro chachitsulo chikhoza kupangidwa kapena kupangidwa kenako nkukonzedwa m'njira zisanu ndi ziwiri zosiyana zopangira. ASTM A513 yokhudzana ndi kupanga chitoliro cha ERW imatchula mitundu isanu ndi iwiri:
Ngati kapangidwe ka mankhwala a chitsulo ndi njira zopangira chubu sizikhudza kuuma kwa chitsulocho, kodi ndi chiyani? Kuyankha funsoli kumatanthauza kufufuza tsatanetsatane. Funsoli likubweretsa mafunso ena awiri: Ndi tsatanetsatane wanji, ndipo ndi pafupi bwanji?
Tsatanetsatane wa tinthu tating'onoting'ono tomwe timapanga chitsulo ndi yankho loyamba. Chitsulo chikapangidwa pa mphero yayikulu yachitsulo, sichimazizira kukhala chipika chachikulu chokhala ndi mawonekedwe amodzi. Chitsulo chikazizira, mamolekyu a chitsulocho amakonzedwa m'mawonekedwe obwerezabwereza (makristalo), mofanana ndi momwe chipale chofewa chimapangikira. Makristalo akapangidwa, amasonkhana m'magulu otchedwa tinthu tating'onoting'ono. Pamene kuzizira kukupita patsogolo, tinthu tating'onoting'ono timakula ndikupanga pepala lonse kapena mbale. Tinthu tating'onoting'ono timasiya kukula pamene mamolekyu otsiriza achitsulo amatengedwa ndi tinthu tating'onoting'ono. Zonsezi zimachitika pamlingo wa microscopic chifukwa tinthu tating'onoting'ono ta chitsulo ndi pafupifupi mainchesi 64 kapena 0.0025 mulifupi. Ngakhale kuti tinthu tating'onoting'ono tating'onoting'ono tomwe timakhala tofanana ndi timeneti, sitifanana. Zimasiyana pang'ono kukula, malo ozungulira komanso kuchuluka kwa kaboni. Kulumikizana pakati pa tinthu tating'onoting'ono kumatchedwa malire a tinthu tating'onoting'ono. Tinthu tating'onoting'ono timeneti tikalephera, mwachitsanzo chifukwa cha ming'alu yotopa, timakonda kulephera m'malire a tinthu tating'onoting'ono.
Kodi muyenera kuyang'ana kutali bwanji kuti muwone tinthu tooneka? Kukulitsa ka 100, kapena ka 100 ka masomphenya a munthu, ndikokwanira. Komabe, kungoyang'ana chitsulo chosakonzedwa ka 100 mphamvu sikuwonetsa zambiri. Chitsanzocho chimakonzedwa mwa kupukuta chitsanzocho ndikudula pamwamba ndi asidi (nthawi zambiri nitric acid ndi mowa) yotchedwa nitroethanol etchant.
Ndi tinthu tating'onoting'ono ndi lattice yamkati mwawo zomwe zimatsimikiza mphamvu ya kugwedezeka, MYS, UTS ndi kutalika komwe chitsulo chingathe kupirira chisanagwe.
Masitepe opangira zitsulo, monga kupukuta ndi kupukuta chitsulo chotentha ndi chozizira, amaika mphamvu mu kapangidwe ka tirigu; ngati asintha mawonekedwe ake kwamuyaya, izi zikutanthauza kuti kupsinjikako kumawononga tirigu. Masitepe ena opangira, monga kukulunga chitsulocho kukhala ma coil, kuchitsegula, ndikuwononga tirigu wachitsulo kudzera mu chubu chopangira machubu (kuti apange ndikukulitsa chubucho). Kuzizira kokoka chubu pa mandrel kumayikanso mphamvu pa chinthucho, monganso masitepe opangira monga kupanga ndi kupindika kumapeto. Kusintha kwa kapangidwe ka tirigu kumatchedwa dislocations.
Masitepe omwe ali pamwambawa amachepetsa mphamvu ya chitsulo, yomwe ndi mphamvu yake yopirira kupsinjika kwa kukoka (kukoka-kutsegula). Chitsulo chimakhala chofooka, zomwe zikutanthauza kuti chingathe kusweka ngati mupitiliza kuchigwira ntchito. Kutalikirana ndi gawo limodzi la mphamvu ya chitsulo (kupanikizika ndi china). Ndikofunikira kumvetsetsa kuti kulephera nthawi zambiri kumachitika panthawi ya kupsinjika kwa chitsulo, osati kupsinjika. Chitsulo chimalimbana kwambiri ndi mphamvu ya chitsulo chifukwa cha mphamvu yake yayikulu yotalikirana. Komabe, chitsulo chimasokonekera mosavuta chikapanikizika - chimakhala chopindika - chomwe ndi mwayi.
Konkriti imakhala ndi mphamvu yopondereza kwambiri koma yolimba pang'ono poyerekeza ndi konkriti. Zinthu izi ndi zosiyana ndi zachitsulo. Ichi ndichifukwa chake konkriti yomwe imagwiritsidwa ntchito pamisewu, nyumba ndi misewu nthawi zambiri imayikidwa mipiringidzo. Zotsatira zake zimakhala chinthu chokhala ndi mphamvu ngati zipangizo ziwiri: chitsulo chikakhala cholimba, chimakhala cholimba, ndipo chikakhala chopanikizika, chimakhala cholimba.
Pa nthawi yogwira ntchito yozizira, pamene mphamvu ya chitsulo ikuchepa, kuuma kwake kumawonjezeka. Mwanjira ina, chimalimba. Kutengera ndi momwe zinthu zilili, izi zitha kukhala zabwino; komabe, zitha kukhala zovuta chifukwa kuuma kumafanana ndi kusweka. Izi zikutanthauza kuti, pamene chitsulo chikulimba, chimakhala chocheperako; chifukwa chake, chimakhala cholephera.
Mwa kuyankhula kwina, gawo lililonse la ndondomeko limagwiritsa ntchito mphamvu zina za chitoliro. Chimakula pamene chitolirocho chikugwira ntchito, ndipo ngati chili cholimba kwambiri sichigwira ntchito kwenikweni. Kulimba ndi kusweka, ndipo chubu chosweka chingalephereke chikagwiritsidwa ntchito.
Kodi wopanga ali ndi zosankha zilizonse pankhaniyi? Mwachidule, inde. Njira imeneyo ndi yonyowa, ndipo ngakhale si yamatsenga kwenikweni, ili pafupi kwambiri ndi yamatsenga momwe mungathere.
Mwachidule, kupopera chitsulo kumachotsa zotsatira zonse za kupsinjika kwa thupi pa chitsulocho. Njirayi imatenthetsa chitsulocho mpaka kutentha komwe kumachepa kapena kutentha komwe kumapangidwanso, motero imachotsa kusokonekera. Kutengera kutentha ndi nthawi yomwe imagwiritsidwa ntchito popopera, njirayi imabwezeretsa mphamvu zake zina kapena zonse.
Kuzimitsa ndi kuziziritsa kolamulidwa kumathandiza kukula kwa tirigu. Izi ndi zothandiza ngati cholinga chake ndi kuchepetsa kufooka kwa zinthuzo, koma kukula kosalamulirika kwa tirigu kumatha kufewetsa chitsulocho kwambiri, zomwe zimapangitsa kuti chisagwiritsidwe ntchito moyenera. Kuletsa njira yozimitsira ndi chinthu china chofanana ndi chamatsenga. Kuzimitsa kutentha koyenera ndi chozimitsira choyenera panthawi yoyenera kumapangitsa kuti ntchitoyi iyime mwachangu kuti chitsulocho chipeze mphamvu zobwezeretsa.
Kodi tiyenera kusiya mfundo yofunikira pa kuuma? Ayi. Makhalidwe a kuuma ndi ofunika makamaka ngati mfundo yofotokozera pofotokoza mapaipi achitsulo. Muyeso wothandiza, kuuma ndi chimodzi mwa makhalidwe angapo omwe ayenera kufotokozedwa poyitanitsa zinthu zozungulira ndikuyang'aniridwa akalandira (ndipo ayenera kulembedwa ndi kutumiza kulikonse). Pamene kuyang'anira kuuma ndiye muyezo wowunikira, uyenera kukhala ndi miyeso yoyenera komanso magawo owongolera.
Komabe, si mayeso enieni a zinthu zoyenera (kuvomereza kapena kukana). Kuwonjezera pa kuuma, opanga nthawi zina ayenera kuyesa kutumiza kuti adziwe zinthu zina zofunika, monga MYS, UTS, kapena kutalika kochepa, kutengera momwe chubucho chimagwiritsidwira ntchito.
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.
Magazini ya Tube & Pipe Journal inakhala magazini yoyamba yodzipereka kutumikira makampani opanga mapaipi achitsulo mu 1990. Masiku ano, ikadali magazini yokhayo ku North America yodzipereka ku makampani opanga mapaipi ndipo yakhala gwero lodalirika kwambiri la chidziwitso kwa akatswiri opanga mapaipi.
Tsopano popeza tili ndi mwayi wopeza kope la digito la The FABRICATOR, titha kupeza mosavuta zinthu zofunika kwambiri m'makampani.
Magazini ya digito ya The Tube & Pipe Journal tsopano ikupezeka mosavuta, zomwe zimapangitsa kuti zinthu zofunika kwambiri m'makampani zipezeke mosavuta.
Sangalalani ndi mwayi wonse wopeza kope la digito la STAMPING Journal, lomwe limapereka kupita patsogolo kwaposachedwa kwaukadaulo, njira zabwino kwambiri komanso nkhani zamakampani pamsika woponda zitsulo.
Sangalalani ndi mwayi wonse wopeza kope la digito la The Additive Report kuti mudziwe momwe kupanga zowonjezera kungagwiritsidwire ntchito kuti kuwonjezere magwiridwe antchito ndikuwonjezera phindu.
Tsopano ndi mwayi wonse wopeza kope la digito la The Fabricator en Español, mwayi wopeza zinthu zofunika kwambiri m'makampani.