Insimbi engenasici ye-Ferritic ibhekiselele kwintsimbi engenasici kunye ne-cubic ferrite egxile kumzimba njengesakhiwo sematrix kwiqondo lokushisa eliphezulu kunye nobushushu obuqhelekileyo. Insimbi engenasici yeFerritic inentsimbi kunye nechromium njengezona zinto ziphambili, aziqulathanga nickel, kwaye ezinye ziqulathe isixa esincinci semolybdenum, titanium okanye niobium kunye nezinye izinto. Inokumelana ne-oxidation elungileyo, ukumelana nokugqwala kunye nokumelana nokuqhekeka kwekloridi. Ukongeza, insimbi engenasici ye-ferritic nayo ineempawu zokuqhuba kwe-thermal enkulu, i-coefficient encinci yokwandisa, ukuchasana kakuhle kwe-oxidation, kunye noxinzelelo olugqwesileyo lokuxhathisa i-corrosion. Isetyenziswa kakhulu ukwenza iindawo ezikwaziyo ukumelana ne-atmospheric, umphunga wamanzi, amanzi, kunye ne-oxidative acid corrosion. Amabanga amele i-ferritic steel stainless: AISI 410 (UNS S41000), AISI 420 (UNS S42000), AISI 430 (UNS S43000) ngokwe-ASTM; 1.4006, 1.4021, 1.4016, ngokomgangatho we-EN ... njl.
Intsimbi ye-Ferritic engenasici inokwahlulwa ibe yichromium ephantsi, i-chromium ephakathi kunye ne-chromium ephezulu ngokomxholo wechromium. Ngokobunyulu bentsimbi, ngakumbi umxholo wokungacoceki kwekhabhoni kunye ne-nitrogen, inokwahlulwa ibe yintsimbi eqhelekileyo ye-ferritic ecocekileyo kunye ne-ultra-pure ferritic stainless steel. Intsimbi eqhelekileyo yeferritic stainless steel inento engalunganga yobushushu obuphantsi kunye nobuqhetseba begumbi lobushushu, ubuntununtunu benotshi, utyekelo oluphezulu lwe-intergranular corrosion, kunye ne-weldability engalunganga. Nangona olu hlobo lwentsimbi lwaphuhliswa ngaphambili, ukusetyenziswa kwayo kwimizi-mveliso kuye kwathintelwa kakhulu. Ezi ntsilelo zentsimbi eqhelekileyo ye-ferritic stainless steel zihambelana nokucoceka kwentsimbi, ngokukodwa umxholo ophezulu wezinto ezidibeneyo ezifana nekhabhoni kunye ne-nitrogen kwintsimbi. Ngethuba nje i-carbon kunye ne-nitrogen kwintsimbi iphantsi ngokwaneleyo, iintsilelo ezingentla zinokoyiswa.
Xa kuthelekiswa neintsimbi ye-austenitic, insimbi engenasici ye-ferritic inokumelana nokugqwala okungcono, ukumelana nobushushu kunye nokuqhubekeka. Kuba isigaba se-ferrite asinakukwazi ukunyibilikisa ikhabhoni, i-ferrite ineempawu zokuthamba kwaye kulula ukuyikhubaza. Njengentsimbi ye-martensitic, kuba i-lattice isakhiwo sigxile kumzimba we-cubic structure, i-paramagnetic, ngoko ke i-ferritic stainless steel inomagnetic. I-Austenitic stainless steel ayiyo-magnetic ngenxa yesakhiwo sayo se-cubic ebusweni.
Ixabiso le-ferritic steel stainless ayilona nje eliphantsi kwaye lizinzile, kodwa linezinto ezininzi ezikhethekileyo kunye neenzuzo. Kuye kwangqinwa ukuba i-ferritic stainless steel yinto egqwesileyo kakhulu.
Intsimbi eqhelekileyo yeferritic
Iintsimbi ezinjalo ziquka izinto eziphantsi, eziphakathi kunye neziphezulu zechromium. I-Low-chromium ferritic steel stainless steel iqulethe malunga ne-11% ukuya kwi-14% ye-chromium, efana ne-00Cr12 kunye ne-0Cr13Al e-China. American AISI 400, 405, 406MF-2. Olu hlobo lwentsimbi lunokuqina okuhle, iplastiki, i-deformation ebandayo kunye ne-weldability. Ngenxa yokuba intsimbi iqulethe inani elithile lechromium kunye ne-aluminium, inokumelana ne-oxidation efanelekileyo kunye nokumelana nokugqwala. I-405 ingasetyenziselwa njengenqaba yokucoca i-petroleum, i-tank lining, i-blade ye-injini ye-steam, isixhobo sokumelana nobushushu besulfure, njl njl. I-400 yezixhobo zendlu kunye ne-ofisi, njl. njl. Intsimbi ephakathi yechromium ferritic, umxholo wechromium yi-14% ukuya I-19%, njenge-1Cr17 kunye ne-1Cr17Mo e-China. AISI 429, AISI 430, AISI 433, AISI 434, AISI 435, AISI 436, AISI 439 eUnited States. Olu hlobo lwentsimbi lungcono ukugqwala kunye nokumelana nokugqwala. Umsebenzi wayo wokuqinisa i-coefficient incinci (n≈2), kwaye inomsebenzi omhle womzobo onzulu, kodwa i-ductility yayo imbi. I-AISI 430 insimbi engenasici ye-ferritic isetyenziselwa ukuhlobisa izakhiwo, umhlobiso wemoto, izixhobo zasekhishini, izitshisi zegesi kunye neengxenye zezixhobo zoshishino ze-nitric acid, njl njl. I-AISI 434 isetyenziselwa ukuhlobisa kwangaphandle kweemoto kunye nezakhiwo. I-439 isetyenziselwa i-hose yezifudumezi zamanzi egesi, imibhobho yamalahle kunye negesi, njl. States. Iintsimbi ezinjalo zinokuxhathisa okulungileyo kwe-oxidation. I-AISI 442 isetyenziswa ngokuqhubekayo kwi-atmosfera, iqondo lokushisa eliphezulu liyi-1035 ° C, kwaye ubushushu obuphezulu bokusetyenziswa ngokuqhubekayo yi-980 ° C. I-AISI 446 insimbi engenasici ine-oxidation engcono yokuxhathisa.
Ucoceko oluphezulu lweferritic steel
Olu hlobo lwentsimbi lunekhabhoni ephantsi kakhulu, initrogen; i-chromium ephezulu, i-molybdenum, i-titanium, i-niobium kunye nezinye izinto. Njenge China 00Cr17Mo, 00Cr18Mo2, 00Cr26Mol, 00Cr30Mo2. Olu hlobo lwentsimbi luneempawu ezilungileyo zoomatshini (ingakumbi ukuqina), ukuwelda, ukuxhathisa kwe-intergranular corrosion, ukumelana ne-pitting corrosion, ukumelana ne-crevice corrosion, kunye noxinzelelo oluhle kakhulu lokumelana nokuqhekeka kwe-corrosion. Ngokomzekelo, i-18-2 i-ferritic stainless steel stainless steel inamandla okumelana ne-corrosion kwi-nitric acid, i-acetic acid, i-NaOH, i-pitting resistance corrosion kwi-3% ye-NaCl kunye ne-FeCl3 ilingana okanye idlula i-18-8 i-austenitic stainless steel, i-26CrMo yensimbi kwimithombo yeendaba ezininzi. , ngokukodwa kwi-acids eziphilayo, i-oxidizing acids, kunye ne-alkali enamandla. Inokumelana ne-corrosion ye-pitting elungileyo kwindawo eyomeleleyo ye-chloride. Akukho xinzelelo lwe-corrosion cracking eyenzekayo kwi-chloride, i-hydrogen sulfide, i-asidi ye-sulfuric eninzi kunye ne-alkali eyomeleleyo. I-30Cr-2Mo inokumelana okuphezulu kwi-corrosion kunye ne-crevice corrosion ngelixa igcina uxinzelelo lwe-corrosion resistance.
Ukumelana nokubola kwentsimbi ye-ferritic
(1) Umhlwa ofanayo.
I-Chromium yeyona nto ilula ukuyenza. Kwimekobume ye-atmospheric, i-alloy ye-iron-chromium enomxholo we-chromium engaphezu kwe-12% iyakwazi ukuzidlula. Kwi-oxidizing medium, umxholo wechromium unokugqithiswa ukuba ungaphezulu kwe-17%. Kwezinye izinto ezityiwayo, i-chromium ephezulu kunye ne-molybdenum, i-nickel, i-copper kunye nezinye izinto zingongezwa ukufumana ukuxhathisa okulungileyo kokuhlwa.
(2) I-Intergranular corrosion.
Iintsimbi ze-Ferritic stainless, ezifana ne-austenitic stainless steels, zinengxaki ye-intergranular corrosion, kodwa unyango lwe-sensitization kunye nobushushu ukunqanda oku kuhlwa kuchasene. I-Ferritic steel stainless steel ixhomekeke kwi-intergranular corrosion ukusuka ekupholiseni ngokukhawuleza ngaphezu kwe-925 ° C, kwaye i-state (i-sensitized state) echaphazelekayo kwi-corrosion ye-intergranular inokupheliswa emva kwexesha elifutshane lokufudumala kwi-650-815 ° C. I-intergranular corrosion yensimbi ye-ferritic nayo isiphumo sokunciphisa i-chromium ebangelwa yi-carbide precipitation. Ngoko ke, ukunciphisa umxholo wekhabhoni kunye ne-nitrogen kwintsimbi kunye nokongeza izinto ezifana ne-titanium kunye ne-niobium kunokunciphisa ukuthinteka kwi-corrosion intergranular.
(3) Umbhobho kunye nomhlwa.
I-Chromium kunye ne-molybdenum zezona zinto zisebenzayo zokuphucula i-pitting kunye ne-crevice corrosion resistance of steel stainless. Njengoko umxholo we-chromium ukhula, umxholo we-chromium kwifilimu ye-oxide nawo uyanda, kwaye ukuzinza kweekhemikhali kwefilimu kuyanda. I-Molybdenum i-adsorbed kwi-metal surface esebenzayo ngendlela ye-MoO4, evimbela ukuchithwa kwesinyithi, ikhuthaza ukubuyiswa kwakhona, kunye nokuthintela umonakalo wefilimu. Ke ngoko, i-chromium ephezulu kunye nentsimbi ye-molybdenum ferritic inoxhathiso olugqwesileyo kwi-pitting kunye ne-crevice corrosion.
(4) Ukumelana noxinzelelo lwe-corrosion cracking.
Ngenxa yeempawu zesakhiwo sombutho, i-ferritic stainless steel i-corrosion-resistant kwi-medium apho i-austenitic stainless steel ivelisa i-stress corrosion cracking.
Iipropati ze-Mechanical zentsimbi ye-ferritic stainless
Insimbi engenasici yeFerritic ayinakomelezwa ngonyango lobushushu kuba akukho tshintsho lwesigaba. Ngokuqhelekileyo, isetyenziswa emva kokufunxa kwi-700-800 ° C. Ngenxa yobukhulu obufanayo beathom yentsimbi kunye nechromium, isisombululo esiluqilima sincinci, amandla esivuno kunye namandla azinzileyo entsimbi ecocekileyo ye-ferritic angaphezulu kancinci kunokwentsimbi ephantsi yekhabhoni, kwaye i-ductility ingaphantsi kuneyentsimbi ephantsi yekhabhoni. .
1) Iqondo lobushushu begumbi brittleness eqhelekileyo ferritic steel stainless.
Intsimbi eqhelekileyo yeferritic stainless steel inovakalelo kwiinotshi, kwaye iqondo lobushushu lenguquko elibrittle lingaphezulu kobushushu begumbi ngaphandle kwentsimbi ephantsi yechromium ferritic. Okukhona uphezulu isiqulatho sechromium, kokukhona ukubanda brittleness. Le brittleness ebandayo inxulumene nezinto ezidibeneyo ezifana nekhabhoni kunye ne-nitrogen kwintsimbi, kwaye i-ultra-pure ferritic steel inomxholo ophantsi kakhulu wekhabhoni kwizinto ezidibeneyo ezifana nekhabhoni kunye ne-nitrogen, ngoko ke inokufumana ubunzima obuhle, kunye nokuguquka kwe-brittle. ubushushu bunokuthotywa ngaphantsi kobushushu begumbi.
2) Ukushisa okuphezulu kwe-embrittlement yentsimbi eqhelekileyo ye-ferritic stainless.
Intsimbi eqhelekileyo yeferritic stainless steel ifudunyezwa ngaphezu kwe-927 ° C kwaye emva koko ipholile ngokukhawuleza kwiqondo lokushisa, iplastiki kunye nokuqina kuyancitshiswa kakhulu. Le embrittlement yobushushu obuphezulu ihambelana nokukhawuleza kwemvula yekhabhoni (i-nitride) iikhompawundi kwimida yengqolowa okanye ukuchithwa kwiqondo lokushisa kwe-427-927 ° C. Ukunciphisa umxholo wekhabhoni kunye ne-nitrogen yentsimbi (usebenzisa iteknoloji ye-ultra-pure) inokuphucula kakhulu le brittleness. Ukongezelela, xa insimbi ye-ferritic ishushu ngaphezu kwe-927 ° C, amandla okuziinkozo aya kuba lukhuni, kwaye ingqolowa enqabileyo iya kutshabalalisa iplastiki kunye nokuqina kwentsimbi.
3) Ukwenziwa kwesigaba σ.
Ngokomzobo wesigaba se-iron-chromium, xa igcinwe kwi-500-800 ° C, i-alloy equlethe i-40% -50% yechromium iya kwenza isigaba esinye σ, kwaye i-alloy equkethe ngaphantsi kwe-20% okanye ngaphezulu kwe-70% yechromium iya kwenza. i-α+σ isakhiwo sesigaba esimbini. Ukuqulunqwa kwe-σ-phase kuya kunciphisa kakhulu i-ductility kunye nokuqina kwentsimbi. Ngoko ke, i-ferritic steel stainless ayifanele isetyenziswe ixesha elide kwi-500-800 ° C.
4) Ubuqhophololo kwi475°C.
I-chromium ephezulu (> 15%) intsimbi ye-ferritic iya kufakwa ngamandla xa igcinwe kwi-400-500 °C. Olu hlobo lwe-embrittlement luthatha ixesha elifutshane kunemvula yesigaba se-σ. Ngokomzekelo, xa i-0.080C-0.4Si-16.9Cr i-ferritic stainless steel igcinwa kwi-450 ° C kwiiyure ze-4, ukuqina kwefuthe lokushisa kwegumbi kuphantse kwehla ukuya kwi-zero. Iqondo le-embrittlement liyenyuka ngokunyuka komxholo wechromium, kodwa ukuqina kunokubuyiselwa emva konyango olungaphezulu kwe-600 °C. I-embrittlement kwi-475 ° C sisiphumo semvula yesigaba se-alpha esityebileyo nge-chromium. Intsimbi enjalo kufuneka iphephe ukufudumeza kufuphi ne-475 ° C.
Ixesha lokuposa: May-02-2023