Ukadaulo wakumbuyo:
Ma fasteners apamwamba kwambiriamafuna quenching ndi kutentha mankhwala malinga ndi zofunikira luso.Kutentha mankhwala kuzimitsa ndi kutenthandi kukonza zida zonse zamakina a zomangira kuti zikwaniritse mphamvu yokhazikika komanso kuchuluka kwa zokolola zazinthu. Njira yochizira kutentha imakhudza kwambiri mkati mwa zomangira zolimba kwambiri, makamaka zamkati mwawo. Panthawi yozimitsa ndi kutentha kutentha, mpweya wina wa okosijeni nthawi zambiri umabweretsedwa kuchokera kunja kwa ng'anjo. Mpweya wa okosijeni umakhudzidwa ndi bawuti, zomwe zimapangitsa kuti pakhale decarburization pamwamba pa bawuti. Chifukwa cha mawonekedwe osiyanasiyana amkati ndi amkati, ali ndi ma coefficients okulitsa osiyanasiyana. Panthawi yozimitsa, ming'alu ya pamwamba ikhoza kuchitika, kuchepetsa khalidwe la mankhwala. Njira yachikhalidwe yochizira kutentha imaphatikizapo kuyika mabawuti mwachindunji mung'anjo yozimitsa kuti azimitse kutentha kwambiri. Panthawi yozimitsira ndi kutenthetsa, mavuto monga kuuma kosakwanira mu chikhalidwe chozimitsidwa, kuuma kosagwirizana mu chikhalidwe chozimitsidwa, kuphulika kwakukulu kozimitsira, ndi kuphulika kozimitsa kumachitika. Pazifukwa izi, ndikofunikira kukonza njira zochiritsira zachikhalidwe.
Zinthu zoyendetsera ukadaulo:
Kuti athane ndi zofooka zaukadaulo womwe ulipo, cholinga cha zomwe zidapangidwa pano ndikupereka njira yochizira kutentha kwa mabawuti okhala ndi mphamvu yozimitsa bwino, kukhathamiritsa kwazinthu, komanso moyo wotalikirapo wautumiki wazinthu.
Kuti akwaniritse zolinga zomwe zili pamwambazi, zomwe zidapangidwa pano zimagwiritsa ntchito njira zotsatirazi zaukadaulo:
Njira yochizira ma bolts imaphatikizapo izi:
S1. Dephosphorization;
S2. Chithandizo chisanachitike: Ikani mankhwalawa mu ng'anjo yoyaka moto ndipo mosalekeza mubaya mpweya wa nayitrogeni wotentha kwambiri mu ng'anjo yoyaka moto. Mutatha kutentha kwa maola 2.5 mpaka 3, chotsani ndikuchiyika mu ng'anjo ya carburizing kuti muchiritse carburization;
S3. Kuzimitsa: Ikani mankhwala mu ng'anjo yozimitsa ndipo mosalekeza kubaya nayitrogeni mu ng'anjo yozimitsa. Mukabaya nayitrogeni kwa mphindi 30-40, pang'onopang'ono kwezani kutentha kwa ng'anjo yozimitsa mpaka 460-500 ℃ ndikuyisunga kwa mphindi 15-20 musanayambe gawo loyamba la kuzimitsa; Pang'onopang'ono onjezerani kutentha kwa ng'anjo yozimitsa mpaka 550 ~ 700 ℃ ndikuyisunga kwa mphindi 20 ~ 35 musanayambe siteji yachiwiri ya mankhwala; Pang'onopang'ono kuonjezera kutentha kwa ng'anjo quenching 750-850 ℃ ndi kusunga kwa mphindi 30-45 musanayambe ndi gawo lachitatu quenching mankhwala;
S4. Kuziziritsa mafuta: Chotsani chozimitsidwa ndikuchiyika mu thanki yoyamba yozimitsa mafuta kuti muziziziritsa mafuta, ndikuyambitsa mphindi 15 zilizonse ndikuzisunga kwa mphindi 20-30; Mukachotsa, ikani mu thanki yachiwiri yozimitsa mafuta kuti muziziziritsa mafuta, yambitsani mphindi 15 zilizonse mpaka kutentha kwazinthu kutsika mpaka 100 ℃;
S5. Kuchotsa mafuta: Chotsani choziziritsa ndikuchisiya kuti chiyime kwa mphindi 35-45, ndikuwotcha mafuta oziziritsa pamwamba pa mankhwalawa kudzera mumpweya wozizira;
S6. Kuwotcha: Ikani mankhwala degreased mu ng'anjo kutentha kutentha mankhwala, kusintha kutentha kwa 110 ~ 180 ℃, ndi tempering nthawi 1.5 ~ 3 hours. Kuchita gawo loyamba la tempering mankhwala; Kwezani kutentha kwa 370-410 ℃ ndi kupsya mtima kwa maola 3-6 musanayambe gawo lachiwiri la chithandizo cha kutentha; Pambuyo pa kutentha, mpweya uziziziritsa mankhwalawa mpaka kutentha.
Makamaka, mu sitepe S1 pamwamba, njira yoyeretsera imakhala ndi zigawo zotsatirazi ndi misa: 20-36 mbali butyl acetate, 10-13 mbali polyglycolic asidi, 16-20 mbali aminoacetic asidi, 13-22 mbali ya ethyl acrylate, 5-9 mbali olemine 6 triethano, 3-9 mbali ya olemine 6 triethano, ndi 3-9 chigawo triethano Magawo 18-26 amadzi, omwe amatha kuchotsa madontho amafuta pamwamba pa chinthucho ndikupewa kukhudza kuzimitsa.
Makamaka, thanki ya dephosphorization yomwe tatchulayi ili ndi njira ya dephosphorization, yomwe imasankha njira ya potaziyamu hydroxide yokhala ndi 2.2-6.5g/l kapena sodium hydroxide solution yokhala ndi 2.8-6.9g/l.
Makamaka, mu sitepe s2 yomwe tatchulayi, mpweya wotentha kwambiri wa nayitrogeni womwe umalowetsedwa mu ng'anjo yoyaka moto ndi mpweya wa nayitrogeni mu ng'anjo yozimitsa mu sitepe s3, ndi kuthamanga kwa 2.5-3.5l / h. Powotcha mankhwalawo, njira yoyeretsera pamwamba pake imatha kuuma ndipo kutentha kwadzidzidzi mu ng'anjo yozimitsa kungapewe kukhudza khalidwe la mankhwala.
Kuphatikiza apo, mu gawo s3 pamwambapa, kuchuluka kwa nayitrogeni ndi 4-5l / h, komwe kumatha kuchotsa mpweya mung'anjo yoyaka moto, kupewa makutidwe ndi okosijeni pakati pa okosijeni ndi mankhwalawo, ndikupewa kutulutsa mpweya, komwe kungayambitse kulephera kwa zomangira za ulusi ndikufupikitsa moyo wautumiki wa chinthucho.
Makamaka, mu sitepe S3 pamwambapa, kutentha kwa kutentha kwa ng'anjo yozimitsa nthawi yotentha mpaka 460-500 ℃ ndi 30-40 ℃/mphindi, kutentha kwa kutentha kwa 550-700 ℃ ndi 50-60 ℃/min, ndi kutentha kwa 50 ℃ 5 ℃ pa kutentha kwa 5 ℃ 5 ℃. 70-90 ℃/mphindi. The siteji Kutentha quenching mankhwala akhoza kusintha quenching zotsatira za mankhwala ndi kusintha khalidwe la mankhwala.
Makamaka, mu sitepe s4, kutentha kwa mafuta ozimitsa mu thanki yoyamba yamafuta ndi 250-300 ℃, ndipo kutentha kwa mafuta ozizimitsa mu thanki yachiwiri yozimitsa mafuta ndi 50-70 ℃.
Makamaka, mu sitepe s5 pamwamba, kutentha kwa mpweya wozizira ndi 30-35 ℃, ndi liwiro la mphepo ndi 20-25m/s.
Ubwino wa zomwe zapezedwa pano ndikuti njira yopangira kutentha kwa bolt ndi yosavuta, yosavuta kugwiritsa ntchito, ndipo imakhala ndi zotsatira zabwino zozimitsa. Powotcha mankhwalawo, njira yoyeretsera pamwamba pake imatha kuuma, ndipo kuwonjezeka kwadzidzidzi kwa kutentha kwa ng'anjo yozimitsa kungapewe kukhudza khalidwe la mankhwala; Nayitrogeni yotentha kwambiri yomwe imagwiritsidwa ntchito mu ng'anjo yowotchayo imachokera ku ng'anjo yozimitsa, kuchotsa chipangizo chotenthetsera mu ng'anjo yotentha, yomwe ingapulumutse kugwiritsira ntchito mphamvu ndi kuchepetsa ndalama zopangira; Kulowetsa nayitrogeni mu ng'anjo zotenthetsera ndi kuzimitsa kumatha kutulutsa mpweya mkati, kupewa makutidwe ndi okosijeni pakati pa okosijeni ndi zinthuzo, potero kupewa kutulutsa mpweya ndikupangitsa kulephera kwa zomangira zomata, ndikukulitsa moyo wautumiki wa chinthucho; siteji Kutentha quenching mankhwala akhoza kusintha quenching zotsatira za mankhwala ndi kusintha khalidwe lake; Chithandizo choziziritsa mafuta chokhazikika chimatha kuziziritsa bwino zinthu zotentha kwambiri popanda kuwononga mtundu wawo.
Njira yeniyeni yokhazikitsira
M'munsimu ndi mawu oyamba enieni a kupangidwa panopa molumikizana ndi enieni embodiments.
Chitsanzo 1
Njira yochizira ma bolts imaphatikizapo izi:
S1. Dephosphorization;
The kuyeretsa njira tichipeza zigawo zotsatirazi ndi misa: 20 mbali butyl acetate, 10 mbali polyglycolic acid, 16 mbali aminoacetic asidi, 13 mbali ya ethyl acrylate, 5 mbali oleic asidi triethanolamine mchere, 3 mbali ethanolamine, ndi 18 madzi; Tanki ya dephosphorization imakhala ndi njira ya dephosphorization, yomwe imagwiritsa ntchito njira ya potaziyamu hydroxide yokhala ndi 2.2g / l;
S2. Chithandizo chisanachitike: Ikani mankhwalawa mu ng'anjo yoyaka moto ndipo mosalekeza mubaya mpweya wa nayitrogeni wotentha kwambiri mu ng'anjo yoyaka moto. Pambuyo pa kutentha kwa maola 2.5, itulutseni ndikuyiyika mu ng'anjo ya carburizing kuti muthandizidwe ndi carburization;
S3. Kuzimitsa: Ikani mankhwala mu ng'anjo yozimitsa ndipo mosalekeza kubaya mpweya wa nayitrogeni mu ng'anjo yozimitsa. Kuthamanga kwa mpweya wa nayitrogeni ndi 4l / h, ndipo mutatha jekeseni mpweya wa nayitrogeni kwa mphindi 30, pang'onopang'ono muwonjezere kutentha kwa ng'anjo yozimitsa mpaka 460 ℃, ndi kutentha kwa 30 ℃ / min, ndikuyisunga kwa mphindi 15 musanayambe siteji yoyamba ya mankhwala; Pang'onopang'ono onjezerani kutentha kwa ng'anjo yozimitsa mpaka 550 ℃, ndi kutentha kwa 50 ℃ / min, ndikuyisunga kwa mphindi 20 musanayambe gawo lachiwiri la mankhwala; Pang'onopang'ono onjezerani kutentha kwa ng'anjo yozimitsa mpaka 750 ℃, ndi kutentha kwa 70 ℃/mphindi, ndikuyisunga kwa mphindi 30 musanayambe gawo lachitatu la mankhwala;
S4. Kuziziritsa mafuta: Chotsani zomwe zazimitsidwa ndikuziyika mu thanki yoyamba yamafuta kuti aziziziritsa mafuta. Kutentha kwa mafuta ozimitsa ndi 250 ℃, ndikuyambitsa mphindi 15 zilizonse kwa mphindi 20; Mukachotsa, ikani mu thanki yachiwiri yozimitsa mafuta kuti muziziziritsa mafuta, ndikuzimitsa kutentha kwamafuta pa 50 ℃ ndikuyambitsa mphindi 15 zilizonse mpaka kutentha kwazinthu kutsika mpaka 100 ℃;
S5. Kuchotsa mafuta: Chotsani choziziritsa ndikuchisiya icho chiyimire kwa mphindi 35. Chotsani mafuta oziziritsa pamwamba pa mankhwala ndi mpweya wozizira pa kutentha kwa 30 ℃ ndi liwiro la mphepo 20m / s;
S6. Kutentha: Ikani mankhwala otenthedwa mu ng'anjo yowotchera kuti mutenthetse, sinthani kutentha kwa 110 ℃, ndi nthawi yotentha mpaka maola 1.5. Kuchita gawo loyamba la tempering mankhwala; Kwezani kutentha kwa 370 ℃, kupsya mtima kwa maola atatu, ndikupitiriza ndi gawo lachiwiri la chithandizo cha kutentha; Pambuyo pa kutentha, mpweya uziziziritsa mankhwalawa mpaka kutentha.
Mpweya wotentha kwambiri wa nayitrogeni womwe umalowetsedwa mu ng'anjo yoyaka moto mu sitepe s2 wa mawonekedwe awa ndi mpweya wa nayitrogeni wochokera ku ng'anjo yozimitsa mu sitepe s3, ndipo kuthamanga kwa mpweya wotentha kwambiri wa nayitrogeni ndi 2.5l/h.
Chitsanzo 2
Njira zomwe zili mumchitidwewu ndizofanana ndi zomwe zili mu Chitsanzo 1, kupatula pamikhalidwe yeniyeni, yomwe ili ndi izi:
S1. Dephosphorization: ikani mankhwalawo mu makina otsuka ndikutsanulira mu njira yoyeretsera mpaka mankhwalawo amizidwa kwathunthu mu njira yoyeretsera. Sinthani kutentha kwa 50 ℃ ndikuyambitsa 15min iliyonse. Pambuyo poyeretsa kwa 3h, tulutsani mankhwalawa ndikuyika mu thanki ya dephosphorization kuti muthandizidwe ndi dephosphorization;
The kuyeretsa njira tichipeza zotsatirazi zigawo zikuluzikulu: 36 mbali butyl acetate, 13 mbali polyglycolic acid, 20 mbali aminoacetic asidi, 22 mbali ya ethyl acrylate, 9 mbali oleic asidi triethanolamine mchere, 16 mbali ya ethanolamine ndi 26 madzi; Tanki ya dephosphorization imakhala ndi njira ya dephosphorization, yomwe imasankhidwa ngati njira ya potaziyamu hydroxide yokhala ndi 6.5g / l kapena sodium hydroxide solution ndi ndende ya 6.9g / l;
S2. Chithandizo chisanachitike: Ikani mankhwalawa mu ng'anjo yoyaka moto ndipo mosalekeza mubaya mpweya wa nayitrogeni wotentha kwambiri mu ng'anjo yoyaka moto. Pambuyo pa kutentha kwa maola atatu, itulutseni ndikuyiyika mu ng'anjo ya carburizing kuti muthandizidwe ndi carburization;
S3. Kuzimitsa: Ikani mankhwala mu ng'anjo yozimitsa ndipo mosalekeza kubaya mpweya wa nayitrogeni mu ng'anjo yozimitsa. Kuthamanga kwa mpweya wa nayitrogeni ndi 5l / h, ndipo mutatha jekeseni mpweya wa nayitrogeni kwa 40min, pang'onopang'ono muwonjezere kutentha kwa ng'anjo yozimitsa mpaka 500 ℃, ndi kutentha kwa 40 ℃ / min, ndikuyisunga kwa 20min musanapitirize ndi gawo loyamba la kuzimitsa; Pang'onopang'ono onjezani kutentha kwa ng'anjo yozimitsa mpaka 700 ℃, ndi kutentha kwa 60 ℃/mphindi, ndikugwira kwa mphindi 35 musanayambe gawo lachiwiri la kuzimitsa; Pang'onopang'ono onjezerani kutentha kwa ng'anjo yozimitsa mpaka 850 ℃, ndi kutentha kwa 90 ℃/mphindi, ndikugwirani kwa mphindi 45 musanayambe gawo lachitatu la mankhwala;
S4. Kuziziritsa mafuta: Chotsani zomwe zazimitsidwa ndikuziyika mu thanki yoyamba yamafuta kuti aziziziritsa mafuta. Kutentha kwa mafuta oziziritsa ndi 300 ℃, ndikuyambitsa mphindi 15 zilizonse kwa mphindi 30; Mukachotsa, ikani mu thanki yachiwiri yozimitsa mafuta kuti muziziziritsa mafuta, ndikuzimitsa kutentha kwamafuta pa 70 ℃ ndikuyambitsa mphindi 15 zilizonse mpaka kutentha kwazinthu kutsika mpaka 100 ℃;
S5. Kuchotsa mafuta: Chotsani choziziritsa ndikuchisiya icho chiyimire kwa mphindi 45. Chotsani mafuta oziziritsa pamwamba pa mankhwala ndi mpweya wozizira pa kutentha kwa 35 ℃ ndi liwiro la mphepo 25m / s;
S6. Kutenthetsa: Ikani mankhwala otenthedwa mu ng'anjo yowotchera, sinthani kutentha kwa 180 ℃, ndi nthawi yotentha mpaka maola atatu. Kuchita gawo loyamba la tempering mankhwala; Kwezani kutentha kwa 410 ℃, kupsya mtima kwa maola 6, ndikupitiriza ndi gawo lachiwiri la chithandizo cha kutentha; Pambuyo pa kutentha, mpweya uziziziritsa mankhwalawa mpaka kutentha.
Mpweya wotentha kwambiri wa nayitrogeni womwe umalowetsedwa mu ng'anjo yoyaka moto mu sitepe s2 wa mawonekedwe awa ndi mpweya wa nayitrogeni wochokera ku ng'anjo yozimitsa mu sitepe s3, ndikuyenda kwa 3.5l / h kwa mpweya wotentha kwambiri wa nayitrogeni.
Chitsanzo 3
Njira zomwe zili mumchitidwewu ndizofanana ndi zomwe zili mu Chitsanzo 1, kupatula pamikhalidwe yeniyeni, yomwe ili ndi izi:
S1. Dephosphorization;
The kuyeretsa njira tichipeza zigawo zotsatirazi ndi misa: 28 mbali butyl acetate, 12 mbali polyglycolic acid, 18 mbali aminoacetic asidi, 18 mbali ya ethyl acrylate, 7 mbali oleic asidi triethanolamine mchere, 10 mbali ya ethanolamine, ndi 22 madzi; Tanki ya dephosphorization ili ndi yankho la dephosphorization, lomwe limasankhidwa ngati njira yothetsera sodium hydroxide yokhala ndi 4.5g / l;
S2. Chithandizo chisanachitike: Ikani mankhwalawa mu ng'anjo yoyaka moto ndipo mosalekeza mubaya mpweya wa nayitrogeni wotentha kwambiri mu ng'anjo yoyaka moto. Pambuyo pa kutentha kwa maola 2.7, chotsani ndikuchiyika mu ng'anjo ya carburizing kuti muchiritse carburization;
S3. Kuzimitsa: Ikani mankhwala mu ng'anjo yozimitsa ndipo mosalekeza kubaya mpweya wa nayitrogeni mu ng'anjo yozimitsa. Kuthamanga kwa mpweya wa nayitrogeni ndi 4.5l / h, ndipo mutatha kulowetsa mpweya wa nayitrogeni kwa mphindi 35, pang'onopang'ono muwonjezere kutentha kwa ng'anjo yozimitsa mpaka 480 ℃, ndi kutentha kwa 35 ℃ / min, ndikuyisunga kwa mphindi 18 musanayambe ndi gawo loyamba la kuzimitsa; Pang'onopang'ono onjezerani kutentha kwa ng'anjo yozimitsa mpaka 575 ℃, ndi kutentha kwa 55 ℃ / min, ndikuyisunga kwa mphindi 27 musanayambe gawo lachiwiri la mankhwala; Pang'onopang'ono onjezerani kutentha kwa ng'anjo yozimitsa mpaka 800 ℃, ndi kutentha kwa 80 ℃/mphindi, ndikuyisunga kwa mphindi 38 musanayambe gawo lachitatu la mankhwala;
S4. Kuziziritsa mafuta: Chotsani zomwe zazimitsidwa ndikuziyika mu thanki yoyamba yamafuta kuti aziziziritsa mafuta. Kutentha kwa mafuta ozimitsa ndi 275 ℃, ndikuyambitsa mphindi 15 zilizonse kwa mphindi 25; Mukachotsa, ikani mu thanki yachiwiri yozimitsa mafuta kuti muziziziritsa mafuta, ndikuzimitsa kutentha kwamafuta pa 60 ℃ ndikuyambitsa mphindi 15 zilizonse mpaka kutentha kwazinthu kutsika mpaka 100 ℃;
S5. Kuchotsa mafuta: Chotsani choziziritsa ndikuchisiya icho chiyimire kwa mphindi 40. Chotsani mafuta oziziritsa pamwamba pa mankhwalawa kudzera mu mpweya wozizira, ndi kutentha kwa 33 ℃ ndi liwiro la mphepo 22m / s;
S6. Kutenthetsa: Ikani mankhwala otenthedwa mu ng'anjo yotenthetsera kuti muchepetse kutentha, sinthani kutentha kwa 145 ℃, ndi nthawi yotentha mpaka maola 2.2. Kuchita gawo loyamba la tempering mankhwala; Kwezani kutentha kwa 390 ℃, kupsya mtima kwa maola 4.5, ndikupitiriza ndi gawo lachiwiri la chithandizo cha kutentha; Pambuyo pa kutentha, mpweya uziziziritsa mankhwalawa mpaka kutentha.
Nayitrogeni wotentha kwambiri wolowetsedwa mu ng'anjo yoyaka moto mu sitepe s2 ya mawonekedwe awa ndi nayitrogeni mu ng'anjo yozimitsa mu sitepe s3, ndi kutsika kwa 3l/h.
Kuyesa kwamakina ntchito
Malingana ndi zotsatira zoyesa, zikhoza kuwoneka kuti mlingo wa mphamvu zazitsulo zomwe zimagwiritsidwa ntchito ndi njira yopangira kutentha kwazomwe zikuchitika panopa ndi pamwamba pa 10.5, zomwe zimakwaniritsa zofunikira za khalidwe.
Njira yochizira kutentha kwa bolt yomwe yapangidwa pano ndiyosavuta, yosavuta kugwiritsa ntchito, ndipo imakhala ndi zotsatira zabwino zozimitsa. Powotcha mankhwalawo, njira yoyeretsera pamwamba pake imatha kuuma, ndipo kuwonjezeka kwadzidzidzi kwa kutentha kwa ng'anjo yozimitsa kungapewe kukhudza khalidwe la mankhwala; Nayitrogeni yotentha kwambiri yomwe imagwiritsidwa ntchito mu ng'anjo yowotchayo imachokera ku ng'anjo yozimitsa, kuchotsa chipangizo chotenthetsera mu ng'anjo yotentha, yomwe ingapulumutse kugwiritsira ntchito mphamvu ndi kuchepetsa ndalama zopangira; Kulowetsa nayitrogeni mu ng'anjo zotenthetsera ndi kuzimitsa kumatha kutulutsa mpweya mkati, kupewa makutidwe ndi okosijeni pakati pa okosijeni ndi zinthuzo, potero kupewa kutulutsa mpweya ndikupangitsa kulephera kwa zomangira zomata, ndikukulitsa moyo wautumiki wa chinthucho; siteji Kutentha quenching mankhwala akhoza kusintha quenching zotsatira za mankhwala ndi kusintha khalidwe lake; Chithandizo choziziritsa mafuta chokhazikika chimatha kuziziritsa bwino zinthu zotentha kwambiri popanda kuwononga mtundu wawo.
M'mafotokozedwe a izi, mawu oti "chithunzi chimodzi", "zitsanzo zina", "zitsanzo", "zitsanzo zenizeni", kapena "zitsanzo zina" amatanthauza kuti mawonekedwe, zida, zida, kapena mawonekedwe omwe akufotokozedwa molumikizana ndi zomwe zachitika kapena chitsanzo zikuphatikizidwa ndi chimodzi kapena chitsanzo cha zomwe zidapangidwa pano. M'matchulidwe awa, mafotokozedwe atsatanetsatane a mawu omwe ali pamwambawa sakutanthauza zofananira kapena zitsanzo. Kuphatikiza apo, mawonekedwe, zida, zida, kapena zinthu zomwe zafotokozedwa zitha kuphatikizidwa m'njira yoyenera mwachifanizo chilichonse kapena zingapo.
Zomwe zili pamwambazi zikuwonetsa ndikufotokozera mfundo zazikuluzikulu, mbali zazikulu, ndi ubwino wa zomwe zapezedwa. Akatswiri amakampaniwa akuyenera kumvetsetsa kuti zomwe zili pamwambapa sizichepetsa zomwe zidapangidwa pano, ndipo njira zilizonse zaukadaulo zomwe zimapezeka posinthana ndi zina kapena kusintha kofananako zimagwera m'kati mwachitetezo cha zomwe zidapangidwa pano.
Nthawi yotumiza: Apr-04-2023