Izimbangela kanye nezinyathelo zokulwa nokugqwala kwe-pickling yama-flange ensimbi engagqwali angama-304
Umbono: Ikhasimende lisanda kuthenga inqwaba yamaflange ensimbi engagqwali angu-304, okwakumelwe afakwe emanzini anosawoti futhi asuswe ngaphambi kokusetshenziswa. Ngenxa yalokho, ama-bubbles avele ebusweni bensimbi engagqwali ngemuva kokufakwa ethangini lokukhetha isikhathi esingaphezu kwemizuzu eyishumi. Ngemva kokuba ama-flange ekhishiwe futhi ahlanzwa, kwatholakala ukugqwala. Ukuze uthole imbangela yokugqwala kwama-flange ensimbi engagqwali, vimbela izinkinga zekhwalithi ukuthi zingaphinde zenzeke, futhi unciphise ukulahlekelwa kwezomnotho. Ikhasimende lisimeme ngokukhethekile ukuthi silisize ngokuhlaziya amasampula kanye nokuhlola i-metallographic.
Okokuqala, ake ngethule i-304 yensimbi engagqwali flange. Inokumelana nokugqwala okuhle, ukumelana nokushisa, kanye nezakhiwo zemishini ezisezingeni eliphansi. Ayizwani nokugqwala emkhathini futhi imelana ne-asidi. Isetshenziswa kabanzi kumaphrojekthi wepayipi eliwuketshezi njengemboni ye-petroleum namakhemikhali. Njengengxenye ebalulekile yokuxhunywa kwamapayipi, inezinzuzo zokuxhuma nokusebenzisa kalula, ukugcina ukusebenza kokuvalwa kwamapayipi, nokwenza kube lula ukuhlolwa nokushintshwa kwengxenye ethile yepayipi.
Inqubo yokuhlola
- Hlola ukwakheka kwamakhemikhali: Okokuqala, sampula i-flange egqwalile futhi usebenzise i-spectrometer ukuze unqume ngokuqondile ukwakheka kwayo kwamakhemikhali. Imiphumela ikhonjiswe esithombeni esingezansi. Uma kuqhathaniswa nezidingo zobuchwepheshe zokwakheka kwamakhemikhali ensimbi engagqwali angama-304 ku-ASTMA276-2013,okuqukethwe kwe-Cr ekwakhiweni kwamakhemikhali kwe-flange ehlulekile kuphansi kunevelu evamile.
- Ukuhlolwa kwe-Metallographic: Isampula yesigaba esiphambanayo selongitudinal yasikwa endaweni yokugqwala ye-flange ehlulekile. Ngemva kokupholishwa, akuzange kutholwe ukugqwala. I-non-metallic inclusions yabonwa ngaphansi kwe-microscope ye-metallographic futhi isigaba se-sulfide salinganiswa njenge-1.5, isigaba se-alumina silinganiswe njenge-0, isigaba se-asidi sikasawoti silinganiswe njenge-0, futhi isigaba se-spherical oxide silinganiswe njenge-1.5; isampula yaqoshwa yi-ferric chloride hydrochloric acid aqueous solution futhi yabonwa ngaphansi kwe-100x metallographic microscope. Kutholwe ukuthi okusanhlamvu kwe-austenite kuzinto ezibonakalayo azilingani ngokwedlulele. Ibanga likasayizi wokusanhlamvu lihlolwe ngokuya nge-GB/T6394-2002. Indawo yokusanhlamvu eqinile ingalinganiswa njengo-1.5 futhi indawo yokusanhlamvu enhle ingalinganiswa njengo-4.0. Ngokubheka i-microstructure ye-corrosion eseduze-surface, kungatholakala ukuthi ukugqwala kuqala kusuka endaweni yensimbi, kugxile emingceleni yezinhlamvu ze-austenite futhi kudlulele ngaphakathi kwempahla. Imingcele yokusanhlamvu kule ndawo ibhujiswa ukugqwala, futhi amandla okubopha phakathi kwezinhlamvu cishe alahlekile ngokuphelele. Insimbi egqwalile kakhulu ize yakhe impushana, esulwa kalula ebusweni bento.
- Ukuhlaziya Okubanzi: Imiphumela yokuhlolwa ngokomzimba namakhemikhali kubonisa ukuthi okuqukethwe kwe-Cr ekwakhekeni kwamakhemikhali e-flange yensimbi engagqwali kungaphansi kancane kunenani elijwayelekile. Isici se-Cr siyinto ebaluleke kakhulu enquma ukumelana nokugqwala kwensimbi engagqwali. Ingasabela nge-oxygen ukuze ikhiqize ama-Cr oxides, yakhe ungqimba lwe-passivation ukuvimbela ukugqwala; okuqukethwe kwe-sulfide okungeyona i-metallic kule nto kuphezulu, futhi ukuhlanganiswa kwama-sulfide ezindaweni zendawo kuzoholela ekwehleni kwe-Cr concentration endaweni ezungezile, okwenza indawo ye-Cr-poor, ngaleyo ndlela kuthinte ukumelana nokugqwala kwensimbi engagqwali; ngokubheka okusanhlamvu kwe-flange yensimbi engagqwali, kungatholakala ukuthi usayizi wayo wokusanhlamvu awulingani ngokwedlulele, futhi okusanhlamvu okuxubile okungalingani enhlanganweni kuthambekele ekwenzeni umehluko emandleni e-electrode, okuholela kumabhethri amancane, okuholela ekugqwaleni kwe-electrochemical. ubuso bempahla. Izinhlamvu ezixubile nezinhle ze-flange yensimbi engagqwali ikakhulukazi zihlobene nenqubo yokuguqula ukusebenza okushisayo, okubangelwa ukuwohloka okusheshayo kwezinhlamvu ngesikhathi sokubumba. Ukuhlaziywa kwesakhiwo esincane sokugqwala okuseduze kwendawo ye-flange kubonisa ukuthi ukugqwala kuqala kusuka endaweni ye-flange futhi kunabele ngaphakathi eduze komngcele wezinhlamvu ze-austenite. I-high-magnification microstructure yezinto ezibonakalayo ibonisa ukuthi kunezigaba zesithathu ezengeziwe zemvula emngceleni wezinhlamvu ze-austenite wento. Izigaba zesithathu eziqoqwe emngceleni wokusanhlamvu zivame ukubangela ukuncipha kwe-chromium emngceleni wokusanhlamvu, okubangela ukuthambekela kokugqwala kwe-intergranular futhi kunciphisa kakhulu ukumelana kwayo nokugqwala.
Isiphetho
Iziphetho ezilandelayo zingafinyelelwa ezimbangela zokugqwala kokugqwala kwama-flange ensimbi engagqwali angama-304:
- Ukugqwala kwama-flange ensimbi engagqwali kuwumphumela wesenzo esihlanganisiwe sezici eziningi, phakathi kwazo isigaba sesithathu esincipha emngceleni wokusanhlamvu wezinto ezibonakalayo kuyimbangela eyinhloko yokwehluleka kwe-flange. Kunconywa ukuthi ulawule ngokuqinile izinga lokushisa lokushisa ngesikhathi sokusebenza esishisayo, ungeqi izinga lokushisa elingaphezulu lomkhawulo wenqubo yokushisisa, futhi uphole ngokushesha ngemuva kwesixazululo esiqinile ukugwema ukuhlala ebangeni lokushisa elingu-450 ℃-925 ℃ isikhathi eside kakhulu. ukuvimbela ukuna kwezinhlayiya zesigaba sesithathu.
- Izinhlamvu ezixubile ezintweni zijwayele ukugqwala kwe-electrochemical ebusweni bezinto ezibonakalayo, futhi isilinganiso sokubumba kufanele silawulwe ngokuqinile ngesikhathi senqubo yokubumba.
- Okuqukethwe kwe-Cr okuphansi kanye nokuqukethwe okuphezulu kwe-sulfide kokuqukethwe kuthinta ngokuqondile ukumelana nokugqwala kwe-flange. Lapho ukhetha izinto zokwakha, kufanele kuqashelwe ekukhetheni izinto ezinekhwalithi emsulwa ye-metallurgical.