Kudzidza nezveMhedzisiro yeKabhoni paSimbi
Simbi ndeimwe yezvinhu zvakakosha zveinjiniya muindasitiri yemazuva ano, inoshandiswa mune zvese kubva pakuvaka zvivakwa kusvika kumabhiriji, mota, michina, uye kunyange midziyo yemumba. Pakati pezvinhu zvakasiyana-siyana zvekubatanidza zvinogona kuwedzerwa kusimbi, kabhoni ndiyo inonyanya kusarudza hunhu hwayo hwekutanga. Kunyangwe zviri mukati mayo zviri zvishoma kana zvichienzaniswa nechinhu chikuru, simbi, shanduko muhuwandu hwekabhoni mukati mechikamu chakamanikana zvinogona kuburitsa mutsauko mukuru musimba, kuomarara, kuomarara, kuchinjika, uye maitiro ekurapa kupisa. Chinyorwa chino chinokurukura kuti huwandu hwekabhoni hunokanganisa sei magadzirirwo esimbi uye hunhu hwemakanika, uye zvazvinoreva pakusarudzwa kwezvinhu zvemashandisirwo emaindasitiri.
1. Simbi nebasa rekabhoni
Kazhinji, simbi isimbi ine kabhoni (Fe) ine kabhoni (C) sechinhu chikuru chinobatanidza, chinowanzova pakati pe0,02% kusvika pa2,0% (muzana nehukuru). Pamusoro pemhando iyi, simbi dzine kabhoni dzinowanzo rongwa sesimbi yakakandwa. Kabhoni inogona kuvapo mumhinduro yakasimba mukati mesimbi, kana kuumba ma carbide compounds (kunyanya cementite, Fe₃C). Kuvapo kwekabhoni kunokanganisa marongero nekuchinja kwemaatomu esimbi pakupisa nekutonhodza.
Pakupisa kwemumba, simbi yakachena inowanzova nechimiro cheferrite (α-Fe) chakapfava uye chinopfava. Kana kabhoni ikawedzerwa, imwe kabhoni inonyunguduka kana kuita chikamu chakaoma. Saka, kabhoni inoshanda se "kusimbisa," inowedzera simba nekuoma, asi kazhinji nekuda kwekusagadzikana nekusimba.
2. Magadzirirwo emukati memuviri: ferrite, pearlite, uye cementite
Simba guru rekabhoni rinoonekwa muchimiro chesimbi. Musimbi isina kabhoni yakawanda, chimiro chesimbi chinowanzo shandiswa neferrite ine huwandu hushoma hwepearlite. Ferrite yakapfava, inochinjika, uye yakasimba zvikuru. Pearlite musanganiswa weferrite necementite unoumbwa panguva yekutonhodza pane zvimwe zvinhu; pearlite yakaoma uye yakasimba kupfuura ferrite.
Sezvo huwandu hwekabhoni huchiwedzera, huwandu hwepearlite necementite hunowedzera. Pamazinga epakati nepakati ekabhoni, chimiro che microstructure chinova musanganiswa weferrite nepearlite, ine huwandu hwakawanda hwepearlite, zvichikonzera kuwedzera kwesimba nekuomarara. Musimbi dzine kabhoni yakawanda, pearlite inonyanya kupararira, uye proeutectoid cementite (cementite yakagadzirwa eutectoid reaction isati yasvika) inogona kuoneka, zvichikonzera zvinhu zvakaoma asi zvinoputsika.
Muchidimbu:
– Kabhoni yakaderera → ferrite inotonga → yakapfava uye inopinza
– Kabhoni iri pakati nepakati → kuwedzera kwepearlite → kusimba uye kuoma
– Kabhoni yakawanda → pearlite + cementite inowedzera → yakaoma zvikuru, inopfava zvikuru
3. Kukanganiswa kwehunhu hwemakanika
a. Simba rekusimba uye kuomarara
Kuwanda kwekabhoni kunowedzera simba rekusimba uye kuomarara. Izvi zvinoitika nekuti maatomu ekabhoni anodzivirira kufamba kwekubuda kwechinhu mu crystal lattice, zvichiita kuti kushanduka kwepurasitiki kuve kwakaoma. Uyezve, kuwedzera kwezvikamu zve pearlite ne cementite kunowedzera kuramba kupinda nekupfekwa.
Muchokwadi, simbi ine kabhoni shoma yakakodzera zvikamu zvinoda kuchinjika kukuru pasina kutyoka (semuenzaniso maplate, mapaipi, miviri yemotokari), nepo simbi ine kabhoni yakawanda yakakodzera zvikamu zvinoda kuomarara uye kuramba kupfeka (semuenzaniso masipiringi, waya yakasimba, mapanga, nezvimwe zvishandiso).
b. Kusimba uye kusimba
Kusimba uye kusimba kwesimbi zvinowanzodzikira kana kabhoni ichiwedzera. Simbi dzine kabhoni yakawanda dzinogona kutsemuka nekuti magadzirirwo adzo ane zvikamu zvakaoma zvisingakwanise kupinza simba rekukanganisa. Mukushandiswa kwadzo pasi pemitoro inochinja-chinja kana njodzi yekukanganisa, simbi dzine kabhoni shoma kana simbi dzakagadzirwa nealloy dzinowanzo shandiswa nekuda kwekusimba kwadzo.
c. Kusapfeka zvakanaka
Kusapfeka kunowedzera kana simbi dzakanyanya kupiswa nekabhoni, kunyanya kana zvikashandiswa pakurapa kupisa kwakakodzera. Izvi zvakakosha kune zvinhu zvinokweshana zvakaita semagiya, mamwe mashaft, njanji, uye nzvimbo dzinoshanda nemidziyo.
4. Mhedzisiro pakuwirirana uye kugadzirwa
Kuwanda kwekabhoni kunokanganisa zvakanyanya kuchinjika kwesimbi. Simbi dzine kabhoni shoma dzinowanzo kuve nyore kuchinjika nekuti dzine njodzi shoma yekuumba zvivakwa zvisina kusimba munzvimbo ine kupisa (HAZ). Kusiyana neizvi, kuwanda kwekabhoni kunowedzera mukana wekuti martensite inoputika iumbwe panguva yekutonhorera mushure mekuchinjika, izvo zvinogona kukonzera kupwanyika kwechando, kunyanya kana paine hydrogen.
Muindasitiri, simbi ine kabhoni yakawanda inowanzoda nzira dzakakosha dzekubatanidza dzakadai se:
- kupisa,
- kudzora tembiricha pakati pema "interpass",
- kutonhora kunodzorwa,
– uye kurapwa kwekupisa mushure mekuweld (PWHT) kana zvichidikanwa.
Kunze kwekunamira, maitiro ekugadzira akadai sekukombama, kutsika, uye kudhirowa zviri nyorewo nesimbi isina kabhoni yakawanda nekuti chinhu chacho chakanyanya kupfava.
5. Mhinduro yekurapwa nekupisa
Chimwe chikonzero chinoita kuti kabhoni ive yakakosha ndechekuti ine simba pamhedzisiro yekurapa kupisa. Mukuita senge kudzimisa nekudziya, huwandu hwekabhoni hunosarudza kuti martensite yakawanda sei inogona kuumbwa. Martensite chimiro chakaoma kwazvo chinoumbwa nekutonhora nekukurumidza kweaustenite, asi inopwanyika kana isina kudzikiswa.
– Simbi isina kabhoni yakawanda: zvakaoma kuwana kuomarara kwakanyanya nekudzima chete nekuti hakuna kabhoni yakakwana yekuumba martensite yakaoma zvakanyanya.
– Simbi yekabhoni iri pakati nepakati: inogona kuomeswa zvakanaka; inoshandiswa zvakanyanya pazvikamu zvemuchina zvakaita semagiya nemacrankshafts (nekupisa kwakakodzera).
– Simbi ine kabhoni yakawanda: inonyatso shanda kana yaoma; yakakodzera maturusi ekucheka, masipiringi, uye zvinhu zvisingapfeki, asi inoda kuomeswa zvakanaka kudzivirira kuputsika.
Kuwanda kwekabhoni kune chekuitawo nekuomarara, kunyangwe zvimwe zvinhu zvakaita se alloying elements (Cr, Mn, Mo, Ni) uye saizi yetsanga zvine basawo.
6. Kupatsanura simbi zvichibva pane zviri mukati mekabhoni
Muchidimbu, simbi inowanzo kurongwa seizvi:
1. Simbi ine kabhoni shoma (± 0,05–0,25% C)
Mienzaniso yekushandiswa: mapurati ekuvaka, mapaipi, mafuremu, miviri yemotokari, zvikamu zvakasungirirwa.
2. Simbi yekabhoni iri pakati nepakati (± 0,25–0,60% C)
Mienzaniso yekushandiswa: shafts, magiya, mabhaudhi ane simba rakawanda, zvikamu zvemuchina zvakajairika.
3. Simbi ine kabhoni yakawanda (± 0,60–1,0% C kana kupfuura)
Mienzaniso yekushandiswa: masipiringi, tambo dzesimbi, maturusi ekucheka ari nyore, zvinhu zvisingapfeki.
Rudzi rwacho runogona kusiyana zvichienderana nechiyero, asi pfungwa yacho yakafanana: kana kabhoni yakakwira, simba nekuoma kwayo zvinowedzera, asi kana yaoma zvakanyanya panyaya yekusimba uye kugadzirwa kwayo.
7. Zvinorehwa nekusarudza zvinhu muindasitiri
Muinjiniya, kusarudzwa kwesimbi hakusi nyaya yekuti "ndeipi yakasimba," asi pane kuenzana kwehunhu: simba, kuomarara, maitiro ekugadzira, mutengo, uye njodzi yekukundikana. Kune zvivakwa zvikuru zvinoda kuchinjika, simbi ine kabhoni shoma ndiyo inowanzo sarudzwa. Kune zvikamu zvekutumira zvinoda simba uye kuramba kupfeka, simbi ine kabhoni yepakati ine kurapwa kwakakodzera kwekupisa ndiyo yakakodzera. Kune zvishandiso kana mashandisirwo echitubu anoda kuomarara kwakanyanya, simbi ine kabhoni yakawanda ndiyo inonyanya kukosha, kunyangwe njodzi yekutyoka nekutsemuka inofanira kudzorwa.
Mhedziso
Kuwanda kwekabhoni chinhu chikuru chinodzora hunhu hwesimbi. Kuwedzera kabhoni kunowanzo kuwedzera kuomarara, simba rekudhonza, uye kuramba kupfeka, asi kunoderedza kusimba, kuomarara, uye kuchinjika. Kabhoni inosarudzawo mhinduro yesimbi pakupisa, kunyanya kugona kwayo kugadzira martensite, iyo inogona kuwana kuomarara kwakanyanya. Saka, kunzwisisa simba rehuwandu hwekabhoni kwakakosha mukusarudza zvinhu, dhizaini yezvikamu, uye dhizaini yekugadzira maitiro ekuona kuti simbi inosangana nezvinodiwa zvekushanda uye kuvimbika mumunda.
Kana muchida, ndinogona kugadzirisa chinyorwa ichi kuti chienderane nesainzi yakazara (ine matafura emhando yecarbon range, madhayagiramu mapfupi eFe–C, uye bibliography), kana kusanganisira zvidzidzo zvemashandisirwo chaiwo emaindasitiri.
