GX40CrNiSi25-20, kuj raug xaiv los ntawm cov khoom siv naj npawb 1.4848, sawv cev rau qib hwm hauv tsev neeg ntawm austenitic cua sov-cov cam khwb cia hlau resistant thiab sawv yog ib qho ntawm cov khoom siv dav tshaj plaws rau kev thov siab - kub daim ntawv thov nyob rau hauv ntau yam lag luam. Nws lub npe, ua raws li cov qauv xws li EN 10295, qhia meej meej txog nws cov ntsiab lus thiab lub hom phiaj npaj. G qhia nws qhov xwm txheej raws li cov khoom siv casting, thaum lub X qhia txog qhov siab - alloy steel. Cov lej thiab cov cim 40CrNiSi25-20 taw tes rau nws cov yam ntxwv txhais: cov ntsiab lus carbon ntawm kwv yees li 0.40 feem pua, cov ntsiab lus tseem ceeb chromium thiab npib tsib xee alloying, nrog chromium tsom ib ncig ntawm 25 feem pua thiab npib tsib xee nyob ib ncig ntawm 20 feem pua. Cov khoom no yog tsim los ua kom tau zoo nyob rau hauv qhov chaw kub siab tshaj plaws uas cov khoom yuav tsum tau tshwj xeeb oxidation tsis kam, siab mechanical zog, thiab zoo heev structural stability nyob rau hauv lub sij hawm thermal raug. Nws pom ntau daim ntawv thov nyob rau hauv kev lag luam furnaces, petrochemical kev teeb tsa, cov khoom siv kho cua sov, thiab cov chaw tsim hluav taws xob, tshwj xeeb tshaj yog qhov uas yuav tsum tau ua kom tsis muaj zog corrosive atmospheres nrog rau kev muaj peev xwm thauj khoom ntawm qhov kub siab.
Qhov tshwj xeeb kev ua tau zoo ntawm GX40CrNiSi25-20 yog lub hauv paus hauv paus hauv nws cov tshuaj ua tib zoo sib npaug ntawm cov tshuaj muaj pes tsawg leeg, uas sawv cev rau kev ua kom zoo ntawm cov cua sov austenitic-cov tsev neeg hlau resistant. Cov lus qhia tshwj xeeb yuav tsum muaj cov pa roj carbon ntau ntawm 0.3 txog 0.5 feem pua ntawm qhov hnyav. Cov pa roj carbon qib no yog qhov tseem ceeb rau kev muab cov khoom siv nrog lub zog txaus thiab nkag siab ntawm qhov kub thiab txias los ntawm kev tsim cov carbides ruaj khov, kom ntseeg tau tias cov khoom siv tswj hwm lawv cov qauv kev ntseeg siab nyob rau hauv lub sijhawm ntev ntawm kev siv tshuab. Qhov tshwj xeeb tshaj plaws ntawm cov hlau no yog nws cov ntsiab lus chromium siab, teev ntawm 24.0 thiab 27.0 feem pua. Qhov muaj ntau ntawm chromium no yog qhov laj thawj tseem ceeb rau cov hlau zoo heev rau oxidation thiab corrosion ntawm qhov kub siab. When exposed to oxidizing atmospheres at elevated temperatures, chromium promotes the formation of a dense, adherent, and stable chromium oxide layer on the surface. Cov txheej no ua raws li kev tiv thaiv kev tiv thaiv, tiv thaiv cov hlau hauv qab los ntawm kev tawm tsam ntxiv los ntawm cov pa oxygen, sulfur, thiab lwm yam corrosive combustion gases, yog li tiv thaiv kev scaling thiab cov khoom degradation. Cov ntsiab lus npib tsib xee, tau teev nyob nruab nrab ntawm 19.0 thiab 22.0 feem pua, yog qhov tseem ceeb sib npaug vim nws ruaj khov austenitic microstructure, muab kev txhim kho siab -kub lub zog, zoo dua ductility, txhim khu kev tiv thaiv rau thermal qaug zog, thiab kev ua tau zoo nyob hauv carburizing ib puag ncig piv rau qib ferritic. Silicon, tam sim no nyob rau hauv thaj tsam ntawm 1.0 mus rau 2.5 feem pua, ua haujlwm nrog chromium thiab npib tsib xee. Nws tsis tsuas yog txhim khu lub fluidity ntawm cov hlau molten thaum lub sij hawm casting txheej txheem tab sis kuj pab tsim kom muaj ib tug zoo dua thiab tiv thaiv oxide nplai, ntxiv bolstering cov ntaub ntawv tsis kam mus rau high-kub oxidation. Lwm cov ntsiab lus tau khaws cia kom tswj tau qhov siab tshaj plaws kom muaj kev ncaj ncees ntawm lub hauv paus alloy. Manganese tsuas yog txwv rau qhov siab tshaj plaws ntawm 2.0 feem pua, thiab ob qho tib si phosphorus thiab sulfur raug txwv rau qib qis, feem ntau yog qhov siab tshaj ntawm 0.04 feem pua thiab 0.03 feem pua, raws li, kom ntseeg tau zoo castability thiab tiv thaiv cov teeb meem xws li kub tawg. Molybdenum kuj tseem tuaj yeem muaj tab sis tsuas yog nyob rau hauv cov nyiaj seem, nrog rau qhov siab tshaj plaws ntawm 0.5 feem pua.
Cov khoom siv kho tshuab ntawm GX40CrNiSi25-20 muaj kev cuam tshuam txog nws cov txiaj ntsig zoo austenitic thiab nws qhov haum rau qhov xav tau tshaj plaws siab tshaj - qhov kub thiab txias kev pabcuam. Cov qauv kev qhia tshwj xeeb txhais cov txiaj ntsig yam tsawg kawg nkaus tau los ntawm cais cov cam khwb cia ntawm chav tsev kub kom ntseeg tau zoo thiab sib xws. Lub zog tawm los, sawv cev rau qhov kev ntxhov siab uas cov khoom pib deform plastically, feem ntau teev nrog tus nqi tsawg kawg ntawm 220 txog 250 MPa, nrog qee qhov chaw qhia txog qhov tseem ceeb ntawm 234 MPa rau cov ntaub ntawv pov thawj. Lub zog tensile, sawv cev rau qhov siab tshaj plaws ntawm cov khoom siv tuaj yeem tiv taus ua ntej tawg, feem ntau yuav tsum muaj tsawg kawg yog 450 txog 510 MPa, nrog rau qhov tseem ceeb feem ntau nyob ib ncig ntawm 452 MPa. Ductility, ntsuas los ntawm feem pua ntawm elongation tom qab tawg, yog teev nrog qhov tsawg kawg nkaus ntawm 7 mus rau 9 feem pua, txawm tias qhov tseeb qhov tseem ceeb tuaj yeem sib txawv nyob ntawm qhov tshwj xeeb casting thiab kev kho cua sov, nrog elongation ntawm kev tawg feem ntau nyob ib ncig ntawm 7 feem pua. Lub hardness ntawm cov khoom, feem ntau ntsuas siv Vickers los yog Brinell txoj kev, feem ntau nyob ib ncig ntawm 150 mus rau 200 HBW, nrog rau cov nqi xws li 198 HV feem ntau pom nyob rau hauv raws li - nrum mob. Nws yog ib qho tseem ceeb uas yuav tsum nco ntsoov tias cov chav no- qhov kub thiab txias, txawm tias muaj txiaj ntsig zoo rau kev tswj hwm, tsis yog cov qauv tsim tshwj xeeb rau kev siv siab - kub. Hauv kev pabcuam, cov ntaub ntawv kev ua tau zoo yog tswj hwm los ntawm nws qhov kev tiv thaiv rau kev nkag mus, nws muaj peev xwm tiv taus kev ntxhov siab nyob rau lub sijhawm ntev ntawm qhov kub thiab txias yam tsis muaj deformation, thiab nws ntev -lub sij hawm microstructural stability. Tus cwj pwm nkag ntawm GX40CrNiSi25-20 yog qhov cuam tshuam los ntawm nag lossis daus thiab coarsening ntawm M23C6-hom carbides theem nrab, uas muab nag lossis daus ntxiv tab sis tuaj yeem degrade dhau sijhawm los ntawm coarsening kinetics ntawm qhov kub siab. Cov qauv austenitic muab los ntawm cov ntsiab lus npib tsib xee siab muaj lub zog kub kub zoo dua piv rau qib ferritic, ua GX40CrNiSi25-20 haum rau cov kev xav tau tshaj plaws.
Lub cev muaj zog ntxiv txhais qhov tsim nyog ntawm GX40CrNiSi25-20 rau nws cov ntawv thov thiab paub qhov txawv ntawm lwm cov cua sov- qib resistant. Nws qhov ceev yog kwv yees li 7.8 grams ib cubic centimeter, uas yog ib qho tseem ceeb rau siab -alloy austenitic cam khwb cia hlau thiab tseem ceeb rau kev xam qhov hnyav ntawm cam khwb cia Cheebtsam thiab rau tsim lub hom phiaj. Cov khoom cua sov yog qhov tseem ceeb tshwj xeeb rau cov khoom raug thermal cycling thiab kub kub fluxes. Cov ntaub ntawv nthuav tawm cov ntsiab lus ntawm thermal expansion ntawm kwv yees li 16 micrometers ib meter ib Kelvin, uas yog cov yam ntxwv ntawm austenitic steels thiab yuav tsum tau ua tib zoo txiav txim siab nyob rau hauv tsim los tswj thermal stresses thiab xyuas kom meej clearances ntawm txav los yog nyob ib sab qhov chaw. Thermal conductivity yog kwv yees li 15 watts ib 'meter' ib Kelvin nyob rau hauv chav tsev kub, cuam tshuam qhov kub thiab txias gradients nyob rau hauv ib tug tivthaiv thaum tshav kub kub thiab txias. Lub modulus ntawm elasticity, uas ntsuas cov ntaub ntawv nruj, feem ntau yog nyob ib ncig ntawm 195 mus rau 200 gigapascals nyob rau hauv chav tsev kub tab sis txo nrog nce kub, ib qho tseem ceeb uas engineers yuav tsum suav rau hauv cov qauv kev suav ntawm qhov kub thiab txias. Qhov tshwj xeeb kub muaj peev xwm yog kwv yees li 490 joules ib kilogram ib Kelvin, thiab cov khoom muaj ib tug melting ntau yam nrog solidus nyob ib ncig ntawm 1340 degrees Celsius thiab liquidus nyob ib ncig ntawm 1390 degrees Celsius. Ib qho tshwj xeeb tseem ceeb rau cov khoom siv no yog nws qhov kev pabcuam siab tshaj plaws. GX40CrNiSi25-20 yog ntsuas rau kev ua haujlwm tas li mus txog 1100 degrees Celsius hauv oxidizing cua, ua rau nws tsim nyog rau cov kev thov kub siab tshaj plaws uas yuav tsum muaj ob qho tib si oxidation tsis kam thiab txhua yam muaj zog ib txhij. Cov khoom siv kuj pom zoo tiv thaiv sulfidizing thiab carburizing ib puag ncig, txawm tias qhov siab tshaj plaws siv qhov kub thiab txias yuav tsum tau hloov kho nyob ntawm qhov tshwj xeeb atmospheric muaj pes tsawg leeg.
Raws li cov hlau cam khwb cia, GX40CrNiSi25-20 feem ntau yog zoo li tus ua tiav los yog nyob ze -cov khoom tiav los ntawm ntau cov txheej txheem tsim, nrog rau kev nqis peev casting yog qhov tshwj xeeb tshaj yog rau cov geometry nyuaj. G nyob rau hauv nws lub npe qhia hais tias nws cov khoom yog optimized rau raws li - nrum mob, txawm hais tias cov khoom yuav tsum tau muab nyob rau hauv kev daws teeb meem -annealed mob nyob ntawm seb yuav tsum tau daim ntawv thov. Qhov no tso cai rau kev tsim cov geometries intricate xws li lub raj txhawb nqa daim hlau, raj radiant, rauv chais, burner nozzles, grates, annealing thawv, hardening thawv, thiab lwm yam complex qhov chaw siv nyob rau hauv siab - cov khoom kub, uas yuav nyuaj los yog tsis yooj yim sua rau fabricate los ntawm wrought txheej txheem xws li forging los yog dov. Cov khoom muaj txiaj ntsig tshwj xeeb rau nws daim ntawv thov hauv cov roj av thiab cov nroj tsuag nkev, nrog rau hauv cov qhov cub tawg, tempering furnaces, phaj normalizing furnaces, thiab nruam rauv qhov chaw uas cov khoom yuav tsum tiv taus ntev heev rau qhov kub siab nyob rau hauv mechanical load. Ib qho txiaj ntsig tseem ceeb ntawm qib no yog nws qhov zoo weldability, uas txawv nws los ntawm ntau qib siab -carbon heat- qib resistant. Cov txheej txheem vuam tsim nyog siv cov hlau sib txuam, feem ntau yog cov khoom sib xyaw zoo ib yam li E310 series electrodes, raug pom zoo rau kev koom nrog GX40CrNiSi25-20 cov khoom kom ntseeg tau tias kev sib koom ua ke thiab kev ua haujlwm siab kub sib npaug rau cov khoom siv hauv paus. Qhov no weldability tso cai rau fabrication ntawm loj los yog complex cov rooj sib txoos uas tsis tuaj yeem tsim los ua ib qho castings.
Kev xaiv ntawm GX40CrNiSi25-20 rau ib daim ntawv thov tshwj xeeb yog tsav los ntawm nws txoj kev sib xyaw ua ke ntawm siab -kub oxidation tsis kam, txhua yam muaj zog, thiab tsis kam mus rau qhov nyuaj corrosive ib puag ncig. Ib qho ntawm nws qhov tseem ceeb ntawm kev siv yog nyob rau hauv kev tsim kho ntawm industrial furnaces thiab cov khoom siv kho cua sov rau lub tsheb thiab aerospace industries. Nws yog feem ntau ua hauj lwm rau fabricate rollers thiab beams rau dov beam furnaces siv nyob rau hauv kub stamping txheej txheem, qhov twg cov Cheebtsam yuav tsum tsis txhob kub siab xwb tab sis kuj mechanical loads thiab thermal cycling. Cov ntaub ntawv sib xyaw ua ke ntawm lub zog, oxidation tsis kam, thiab thermal qaug zog ua rau nws zoo tagnrho rau cov haujlwm no. Hauv kev lag luam petrochemical thiab refining, GX40CrNiSi25-20 feem ntau yog siv rau cov pa roj carbon monoxide, slit tube kab, thiab lwm yam khoom siv uas yuav tsum tau muaj kev ruaj ntseg nyob rau hauv high-temperature hydrocarbon processing ib puag ncig. Cov ntaub ntawv pov thawj zoo tiv thaiv ob qho tib si oxidizing thiab txo cov cua, ua rau nws muaj txiaj ntsig hauv cov ntawv thov uas muaj cov roj sib txawv. Tsis tas li ntawd, nws pom cov ntawv thov hauv ntau lwm cov txheej txheem kub kub xws li kev tsim cov cement, kev ua cov ntxhia, thiab cov khib nyiab incineration, uas yuav tsum tau ua ke oxidation kuj thiab txhua yam muaj zog. Kev hloov kho cov qauv ntawm cov hlau no nrog me me ntxiv ntawm molybdenum, tungsten, thiab niobium kuj tau tsim los ntxiv txhim kho creep tsis kam rau cov kev thov tshwj xeeb xws li dov beam furnaces.
Thaum piv rau lwm cov cua sov-cov qib resistant, GX40CrNiSi25-20 sawv cev rau qib siab ntawm austenitic thaum tshav kub kub- cov cam khwb cia hlau resistant nyob rau hauv cov ntsiab lus ntawm nickel cov ntsiab lus thiab siab - kub muaj peev xwm. Nws belongs rau tsev neeg ntawm tag nrho austenitic tshav kub-resistant steels, yam ntxwv los ntawm lawv ruaj khov austenitic microstructure los ntawm chav tsev kub mus txog rau lawv cov kev pab cuam kub txwv. Muab piv rau qis dua -nickel austenitic qib xws li GX40CrNiSi27-4, uas tsuas muaj 3 mus rau 6 feem pua nickel, GX40CrNiSi25-20 muaj qhov siab dua siab dua - qhov kub thiab txias, ua haujlwm zoo dua rau kev ua haujlwm ntawm cov roj sulfide thiab kev ua haujlwm zoo dua rau nws cov khoom siv hluav taws xob ntau dua stabilized austenitic qauv. Cov ntsiab lus npib tsib xee siab dua kuj muab kev tiv thaiv zoo dua rau qib sigma embrittlement thaum lub sij hawm ntev - laus, uas tuaj yeem ua rau muaj kev txhawj xeeb hauv qee qib qis dua -nickel austenitic qib. Piv rau cov qib ferritic xws li GX40CrSi28 lossis GX130CrSi29, uas muaj kev tiv thaiv oxidation zoo heev tab sis qis dua siab -lub zog kub, GX40CrNiSi25-20 muab cov khoom zoo tshaj plaws thiab cov ntaub ntawv zoo dua, suav nrog kev sib txuas. Piv nrog rau ntau dua -alloyed npib tsib xee-based superalloys, GX40CrNiSi25-20 muaj kev siv nyiaj ntau dua hauv cov ntawv thov uas qhov kawg ntawm lub zog kub tsis tas yuav tsum tau tab sis qhov zoo oxidation kuj thiab txhua yam ruaj khov mus txog 1100 degrees Celsius yog qhov tseem ceeb. Cov txheej txheem thoob ntiaj teb cuam tshuam muab kev qhia dav dav rau cov khoom thiab kev siv ntawm cov qib sib txawv ntawm cov cua sov-resistant cam khwb cia hlau, tso cai rau cov engineers ua kom paub sib piv raws li cov kev pabcuam tshwj xeeb, hnyav yam xws li kub, huab cua muaj pes tsawg leeg, cov khoom siv kho tshuab, thiab kev xav txog nyiaj txiag.
Nyob rau hauv xaus, GX40CrNiSi25-20 yog ib tug hwm thiab dav muaj pov thawj tshav kub-resistant cam khwb cia hlau uas nws muaj nuj nqis nyob rau hauv nws pom zoo ua ke ntawm siab chromium ntsiab lus rau oxidation kuj thiab siab nickel cov ntsiab lus rau austenitic qauv thiab superior high -kub txhua yam khoom. Nws ua tib zoo teev cov tshuaj muaj pes tsawg leeg ua kom muaj kev tiv thaiv oxide txheej uas tiv thaiv siab - kub corrosion, thaum lub siab austenitic microstructure muab kev txhawb zog, thermal qaug zog, thiab zoo weldability. Raws li ib tug casting alloy, nws muaj zoo heev tsim yooj rau tsim complex, ruaj qhov chaw uas yuav tsum tau tiv thaiv kev sib xyaw los ntawm huab cua kub, mechanical kev nyuaj siab, thiab corrosive cua nyob rau hauv ib co ntawm cov feem ntau xav tau kev lag luam ib puag ncig. Rau cov kws tsim khoom thiab cov neeg tsim qauv ua haujlwm nrog xaiv cov khoom siv rau kev kub siab txog 1100 degrees Celsius, nkag siab txog cov khoom tshwj xeeb thiab muaj peev xwm ntawm GX40CrNiSi25-20 yog qhov tseem ceeb rau kev qhia txog cov khoom siv uas yuav xa cov khoom muaj kev nyab xeeb, kav ntev, thiab kev lag luam. Nws txoj kev lees paub nyob rau hauv cov qauv thoob ntiaj teb, ua ke nrog kev nkag siab dav ntawm nws tus cwj pwm nkag siab thiab microstructure, ua kom nws cov xwm txheej zoo li cov khoom siv ua haujlwm tseem ceeb hauv kev ua haujlwm siab kub.
