Qaphela ukuba ayilulo lonke unyango lwe-post weld heat oluluncedo

01 Ukhetho lwendlela yonyango lobushushu

Isiphumo sonyango lobushushu be-post-weld kumandla obunzima kunye nomda wokukhasa wesinyithi unxulumene nobushushu kunye nexesha lokubamba lonyango lobushushu. Umphumo we-post-weld yonyango lokushisa kwimpembelelo yokuqina kwentsimbi ye-weld iyahluka ngeentlobo zetsimbi ezahlukeneyo. Unyango lobushushu lwasemva kweweld lusebenzisa ubushushu obuthile obuphezulu okanye ubushushu obuqhelekileyo kunye nobushushu obuphezulu. Ukulungiswa kobushushu obuphezulu kunye nobushushu obuphezulu kusetyenziswa ukuwelda igesi. Oku kungenxa yokuba iinkozo zegesi welding welds kunye neendawo ezichatshazelwe bubushushu zirhabaxa kwaye zifuna ukucokiswa, ngoko ke kusetyenziswa unyango oluqhelekileyo. Nangona kunjalo, ukulinganisa okukodwa akukwazi ukuphelisa uxinzelelo olushiyekileyo, ngoko ke ukushisa okuphezulu kuyafuneka ukuphelisa uxinzelelo. I-single medium-temperature tempering ifaneleka kuphela kwi-welding yendibano yezikhongozeli zentsimbi ezisezantsi zekhabhoni ezidityaniswe kwisiza, kwaye injongo yayo kukuphumeza ukupheliswa koxinzelelo oluyintsalela kunye ne-dehydrogenation. Kwiimeko ezininzi, iqondo lobushushu elinye liyasetyenziswa. Ukufudumeza kunye nokupholisa unyango lokushisa akufanele kube ngokukhawuleza, kwaye iindonga zangaphakathi nangaphandle kufuneka zifane.

I-02 Iindlela zokunyanga ukushisa ezisetyenziselwa kwiinqanawa zoxinzelelo

Kukho iintlobo ezimbini zeendlela zokunyanga ukushisa ezisetyenziselwa kwiinqanawa zoxinzelelo: enye yonyango lokushisa ukuphucula iimpawu zomatshini; enye i-post-weld heat treatment (PWHT). Ngengqiqo ebanzi, unyango ubushushu post-weld kunyango ubushushu kwindawo welding okanye amacandelo welding emva kokuba workpiece welded. Imixholo ethile ibandakanya ukuphelisa uxinzelelo, ukuphelisa ngokupheleleyo, isisombululo, ukunyanzeliswa, ukunyanzeliswa kunye nokufudumeza, ukufudumala, ukukhululeka koxinzelelo lobushushu obuphantsi, unyango lobushushu bemvula, njl. oko kukuthi, ukuze kuphuculwe ukusebenza kwendawo welding kunye nokuphelisa iziphumo eziyingozi ezifana ukuwelda uxinzelelo residual, indawo welding kunye neendawo ezinxulumene ngokulinganayo kwaye zifudunyezwe ngokupheleleyo ngezantsi inqanaba lotshintsho lwentsimbi iqondo lobushushu 2, kwaye ngoko ngokufana zipholile. Kwiimeko ezininzi, unyango ubushushu post-weld kuxoxiwe ngokuyimfuneko emva-weld unyango isiqabu ubushushu.

03Injongo yonyango lobushushu emva kweweld

1. Relax welding residual stress.
2. Ukuzinzisa imilo kunye nobukhulu besakhiwo kunye nokunciphisa ukuphazamiseka.
3. Ukuphucula ukusebenza kwezinto zomzali kunye namalungu adityanisiweyo, kubandakanywa: a. Ukuphucula iplastiki yentsimbi ye-weld. b. Ukunciphisa ukuqina kwendawo echaphazelekayo kubushushu. c. Phucula ukuqina kokwaphuka. d. Ukuphucula amandla okudinwa. e. Buyisela okanye uphucule amandla esivuno ancitshisiweyo ngexesha lokubumba okubandayo.
4. Ukuphucula ukukwazi ukumelana noxinzelelo lwe-corrosion.
5. Ukukhupha ngakumbi iigesi ezinobungozi kwintsimbi ye-weld, ngakumbi i-hydrogen, ukukhusela ukwenzeka kokuqhekeka okulibazisekayo.

04Isigwebo semfuneko yePWHT

Ingaba isitya soxinzelelo sidinga unyango lwe-post-weld ubushushu kufuneka lucaciswe ngokucacileyo kuyilo, kwaye inkcazo yoyilo loxinzelelo lwangoku ineemfuno zale nto.
Kwimikhumbi yoxinzelelo oludibeneyo, kukho uxinzelelo olukhulu olushiyekileyo kwindawo ye-welding, kunye nemiphumo emibi yoxinzelelo olushiyekileyo. Kuphela phantsi kweemeko ezithile zibonakaliswa. Xa uxinzelelo olushiyekileyo ludibanisa ne-hydrogen kwi-weld, luya kukhuthaza ukuqina kwendawo echaphazelekayo kubushushu, okubangela ukuba kubekho ukuqhekeka okubandayo kunye nokulibaziseka kokuqhekeka.
Xa uxinzelelo lwe-static olushiyekileyo kwi-weld okanye uxinzelelo oluguquguqukayo ngexesha lokusebenza komthwalo ludityaniswe nefuthe elibi le-medium, linokubangela i-crack corrosion, ebizwa ngokuba yi-corrosion yoxinzelelo. I-Welding i-residual stress kunye nokuqina kwesiseko sezinto ezibangelwa yi-welding zizinto ezibalulekileyo kwisizukulwana soxinzelelo lwe-corrosion cracks.

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Iziphumo zophando zibonisa ukuba umphumo oyintloko wokuguqulwa kunye noxinzelelo oluseleyo kwizinto zetsimbi kukuguqula isinyithi ukusuka kwi-corrosion efanayo ukuya kwi-corrosion yendawo, oko kukuthi, kwi-intergranular okanye i-transgranular corrosion. Ngokuqinisekileyo, ukuqhekeka kwentsimbi kunye ne-intergranular corrosion zombini kwenzeka kwimidiya eneempawu ezithile zentsimbi. Phambi koxinzelelo olushiyekileyo, ubume bomonakalo we-corrosion bunokutshintsha ngokuxhomekeke ekubunjweni, ukugxininiswa kunye nobushushu be-corrosion medium, kunye nomahluko wokubunjwa, umbutho, ubume bomphezulu, imeko yoxinzelelo, njl njl. kunye nendawo ye-weld.

Ingaba iinqanawa zoxinzelelo ezidibeneyo zifuna unyango lwe-post-weld ubushushu kufuneka lugqitywe ngokuqwalaselwa ngokubanzi kwenjongo, ubungakanani (ngokukodwa ubukhulu bodonga), ukusebenza kwezinto ezisetyenzisiweyo, kunye neemeko zokusebenza kwesitya. Unyango lobushushu lwasemva kweweld kufuneka luqwalaselwe nakweyiphi na kwezi meko zilandelayo:

1. Iimeko zokusebenza ezinzima, ezifana neenqanawa ezinodonga olungqingqwa kunye nomngcipheko wokuphuka kwe-brittle kumaqondo aphantsi, kunye neenqanawa ezithwala imithwalo emikhulu kunye nemithwalo etshintshanayo.

2. Iinqanawa zoxinzelelo ezidibeneyo ezinobunzima obudlula umda othile. Kubandakanya iibhoyili, iinqanawa zepetrochemical pressure, njl., ezinemigaqo ekhethekileyo kunye neenkcukacha.

3. Iinqanawa zoxinzelelo ezinozinzo oluphezulu lwe-dimensional.

4. Izikhongozeli ezenziwe ngetsimbi ezinotyekelo oluphezulu lokuqina.

5. Iinqanawa zoxinzelelo ezinomngcipheko woxinzelelo lwe-corrosion cracking.

6. Ezinye iinqanawa zoxinzelelo ezichazwe yimimiselo ekhethekileyo, iinkcukacha kunye nemizobo.

Kwiinqanawa zoxinzelelo ezidibeneyo zensimbi, uxinzelelo olushiyekileyo olufikelela kwindawo yokuvelisa lwenziwa kwindawo ekufutshane ne-weld. Isizukulwana solu xinzelelo lunxulumene nokuguqulwa kwesakhiwo esixutywe ne-austenite. Abaphandi abaninzi babonisa ukuba ukuze kupheliswe uxinzelelo olushiyekileyo emva kwe-welding, ukufudumala kwii-degrees ze-650 kunokuba nefuthe elihle kwiinqanawa zentsimbi ezidibeneyo.

Kwangaxeshanye, kukholelwa ukuba ukuba unyango olufanelekileyo lobushushu alwenziwanga emva kwe-welding, i-corrosion-resistant welded joints ayinakuze ifunyanwe.

Ngokuqhelekileyo kukholelwa ukuba unyango lobushushu bokunciphisa uxinzelelo yinkqubo apho i-workpiece edityanisiweyo ifudunyezwa kwii-500-650 degrees kwaye ipholiswe kancinci. Ukunciphisa uxinzelelo kubangelwa ukukhwela kwiqondo lokushisa eliphezulu, eliqala ukusuka kwi-450 degrees kwi-carbon steel kunye ne-550 degrees kwi-molybdenum-containing steel.

Ukuphakama kweqondo lokushisa, kulula ukuphelisa uxinzelelo. Nangona kunjalo, xa iqondo lokushisa lokuqala lentsimbi ligqithiswa, amandla entsimbi aya kuncitshiswa. Ke ngoko, unyango lobushushu lokunciphisa uxinzelelo kufuneka lulawule izinto ezimbini zobushushu kunye nexesha, kwaye akukho nto iyimfuneko.

Nangona kunjalo, kuxinzelelo lwangaphakathi lwe-weldment, uxinzelelo lwe-tensile kunye noxinzelelo loxinzelelo luhlala luhamba kunye, kwaye uxinzelelo kunye ne-elastic deformation ikhona ngaxeshanye. Xa ubushushu bentsimbi buphakama, amandla okuvelisa ayancipha, kwaye i-deformation ye-elastic yasekuqaleni iya kuba yi-deformation yeplastiki, okukukhulula uxinzelelo.

Ukuphakama kobushushu bokufudumala, ngakumbi ukugqiba uxinzelelo lwangaphakathi kupheliswa. Nangona kunjalo, xa iqondo lokushisa liphezulu kakhulu, umgangatho wensimbi uya kuba ne-oxidized kakhulu. Ukongezelela, ngenxa yokushisa kwe-PWHT yentsimbi ecinyiweyo kunye neyomsindo, umgaqo akufanele udlule ubushushu bokuqala bentsimbi, ngokuqhelekileyo malunga nama-degrees angama-30 ngaphantsi kweqondo lokushisa lokuqala lentsimbi, ngaphandle koko izinto ziya kulahlekelwa ukucima kunye nokucima. isiphumo sokucaphuka, kwaye amandla kunye nokuqina kokwaphuka kuya kuncitshiswa. Le ngongoma kufuneka inikwe ingqwalasela ekhethekileyo kubasebenzi bonyango lokushisa.

Ukuphakama kobushushu bokushisa kwe-post-weld ukuphelisa uxinzelelo lwangaphakathi, ubukhulu beqondo lokuthambisa kwentsimbi. Ngokuqhelekileyo, uxinzelelo lwangaphakathi lunokupheliswa ngokufudumeza kwiqondo lokushisa le-recrystallization yentsimbi. Ubushushu bokubuyisela kwakhona buhambelana ngokusondeleyo nobushushu obunyibilikayo. Ngokubanzi, iqondo lobushushu lokunyibilikisa K=0.4X lokunyibilika (K). Ukusondela kweqondo lokushisa lobushushu kubushushu be-recrystallization, busebenza ngakumbi ekupheliseni uxinzelelo olushiyekileyo.

04 Ukuqwalaselwa kwesiphumo esibanzi se-PWHT

Unyango lobushushu be-post-weld alunanzuzo ngokupheleleyo. Ngokuqhelekileyo, unyango lwe-post-weld heat lunceda ekunciphiseni uxinzelelo olushiyekileyo kwaye lwenziwa kuphela xa kukho iimfuno ezingqongqo zoxinzelelo lwe-corrosion. Nangona kunjalo, uvavanyo lwempembelelo yokuqina kwesampulu lubonise ukuba unyango lobushushu lwasemva kwe-weld aluzange lube luncedo ekuphuculeni ukuqina kwentsimbi egciniweyo kunye nendawo echatshazelwe bubushushu, kwaye ngamanye amaxesha ukuqhekeka kwe-intergranular kunokuthi kwenzeke ngaphakathi koluhlu lokutya okuziinkozo koluchaphazelekileyo. indawo.

Ngaphaya koko, i-PWHT ixhomekeke ekwehlisweni kwamandla ezinto eziphathekayo kumaqondo obushushu aphezulu ukuphelisa uxinzelelo. Ngoko ke, ngexesha le-PWHT, isakhiwo sinokulahlekelwa ukuqina. Kwizakhiwo ezithatha i-PWHT yonke okanye inxalenye, amandla okuxhasa i-weldment kumaqondo aphezulu kufuneka athathelwe ingqalelo ngaphambi kokuba unyango lobushushu.

Ngoko ke, xa uqwalasela ukuba ngaba ukwenza unyango lwe-post-weld heat, izibonelelo kunye nokungalunganga kwonyango lokushisa kufuneka kuthelekiswe ngokubanzi. Ukusuka kwimbono yokusebenza kwesakhiwo, kukho icala eliphucula ukusebenza kunye necala elinciphisa ukusebenza. Ugwebo olufanelekileyo kufuneka lwenziwe ngokusekelwe kumsebenzi osisiseko wokuqwalaselwa ngokubanzi kweenkalo zombini.