Wha's Ultrahigh-Strength Steels (UHSS)?

"Ultra-high strength hlau" hais txog hlau alloy nrog yield zog saum toj 1370 MPa (140kgf / mm2) thiab lub zog tensile siab tshaj 1620 MPa (165kgf / mm2). Lub tswv yim ntawm ultra-high lub zog hlau yog tsim los qhia qhov txawv ntawm cov hluav taws xob muaj zog thiab tau siv dav dav dav hlau thiab cov dav hlau dav dav hauv xyoo tas los.


Kev cais tawm ntawm Ultra-High lub zog hlau

Raws li nws txoj kev ua qoob thiab kev microstructure, UHSS tuaj yeem raug muab faib ua qis rau cov qis qis tshaj li cov qaub ncaug rau cov qaub ncaug pob zeb, ultra-siab zog steel, ultra-low carbon martensite laus tawv hardening ultra-siab zog steel, semi-Austenite nag lossis daus hardening steel hlau, thiab lwm yam.

 

Tsis tshua muaj kev sib haum xeeb UHSS

Tsis tshua muaj txhuam cov kab mob qaum tshaj Cov tshuaj tiv thaiv UHSS cov hnyuv laus yog tsim los ntawm kev sib sib zog nqus hlau. Nws tsuas yog cov tshuaj Ni-Cr-Mo tempered hlau 4340 (40CrNiMo), lub Nickel-Cr-Mo-V steel D6AC (45CrNiMoV) nrog cov ntsiab lus ntawm 0.45%, Cr-Mn-Si-Ni hlau (30CrMnSiNi2A) nrog rau cov ntsiab lus qis ntawm 0.30%, thiab 300M steel (43CrNiSiMoV) uas yog tsim los ntawm kev ntxiv silicon (1.6%) thiab vanadium (0.1%) raws li 4340 steel, thiab Si-Mn-Mo-V or Si -Mn-Cr-V tsis muaj npib tsib xees. Lub tshuab nqus tsev melting muaj peev xwm txo cov ntsiab lus ntawm kev ruaj ntseg nyob hauv cov hlau thiab txhim kho cov khoom txig ntawm cov hlau thiab cov toughness ntawm cov hlau, uas yog siv dav hlau hauv lub nkoj, hauv cov voj voos, lub cav cav, lub zog loj, lub khob ntim.

 

Medium alloy UHSS

Medium alloy thiab carbon dhau los ntawm cov dej khov heev UHSS yog tsim los ntawm 5% Cr pwm. Vim nws muaj zog thiab muaj txiaj ntsim zoo thiab muaj lub zog, muaj kev kub hnyiab zoo thiab ruaj khov lub koom haum, nws yog siv rau kev tsaws tsoo thiab cov foob pob hluav taws thiab lwm yam. Cov qib steel yog H11 thiab H13 thiab lawv qhov tseem ceeb yog: C 0.32% - 0.45%; Cr 4.75% - 5.5%; Mo 1.1% - 1.75%; Si 0.8% - 1.2%


High alloy UHSS

High-alloy medium-carbon Ni- (9Ni - 4Co-- ××) UHSS yog tsim los ntawm lub 9% Ni qis-kub kub uas muaj siab muaj zog thiab tsis tshua muaj kev kub ntxhov tsis sib hloov. kev hloov cov nyom ntawm kev lag luam) ntawm cov hlau thiab txo cov residual austenite. Nyob rau tib lub sij hawm, lub Cheeb Tsav Xwm tseem ua raws li cov cuab yig tshuaj kom tau qhov kev tswj tus kheej ntawm cov hlau kom muaj kev vibration zoo. Ib qho me me ntawm chromium thiab molybdenum muaj kev tiv thaiv siv zog thaum muaj kev kub ntxhov. Cov khoom tseem ceeb ntawm hom no yog HP9-4-25, HP9-4-30, HP9-4-45 thiab AF1410 (0.16% C-10% Ni-14% co-1% Mo-2% Cr-0.05% V ) .Qhov hom UHSS steel muaj qhov sib xyaw kom zoo, kev tswj kev hnyav txhuam thiab vuam cov cuab yeej, thiab siv dav dav hauv cov aerospace thiab submarine shells.

 

Ultra-low carbon UHSS

Ultra-low carbon UHSS, feem ntau hu ua martensitic aging steel, yog tsim los ntawm cov kab mob siab ultra-low Ferro-nickel los yog Ferrro-Nickel-Cobalt Martensite. Nws cov martensite tsis tas yuav tsum txias txias, qhov txawv ntawm qhov kub thiab txias thiab cov isothermal tsim tau txaus; Yog tias rov ua dua, tsis pom muaj qhov tshwm sim li cas hauv cov qes qis Martensite, thiab muaj ib qho zoo kawg nkaus tus cwj pwm (hysteresis) uas yog siv rau kev laus tawv hauv Martensite matrix ntawm qhov kub dua. Raws li cov ntsiab lus ntawm cov keeb xem, cov ntsiab lus ntawm cov laus muaj peev xwm raug muab faib ua 25% rau Ni, 20% Ni, 18% Ni thiab 12% Ni. Ntawm lawv 18% Ni yog dav siv hom. Nws yog ib qho ultra-low carbon Fe-Ni (18%) -Co (8.5%) Cov phom uas muaj cov molybdenum, titanium thiab lwm cov khoom ntxiv, nrog rau 3 qib: 18% Ni (200), 18% Ni (250), thiab 18 % Ni (300) (200, 250, 300 yog tensile muaj zog qib nrog ib chav tsev ntawm Ksi) .Qhov hom hlau muaj zog los ntawm cov nag lossis daus ntawm cov khoom sib xyaw ua ke, siab lub zog. Qhov hom hlau no muaj qhov kev zoo, kev ruaj khov thiab qhov ntev, thiab kev kho kom sov yog ib qho yooj yim, uas yog siv rau aerospace thiab kos duab pob zeb xws li txias extrusion, txias stamping tuag thiab nyob rau hauv.

 

Semi-Austenite UHSS

Raws li kev sib tw high-alloy ultra-high hlau, cov qhabnias ntawm cov neeg ua haujlwm ib nrab ntawm UHSS yog 17-7PH, PH15-7Mo thiab AFC-77, thiab lwm yam. Cov hlau tau kho nrog cov tshuaj tov thiab txias rau qhov chaw sov kom tsim tau cov qauv kev noj qab haus huv . Tom qab txias los yog rhuab mus rau 750 ℃ cov Austenite yog hloov mus rau hauv Martensite. Thaum kawg, ultra-high lub zog hlau nrog ob theem reinforced qauv dispersed ntawm tempered martensite matrix tau ntawm 400-550 ℃. Thaum twg cov hom hlau no siv ntev ntev dua 315 ℃, cov khoom yuav dhau los ua vim yog nag lossis daus ntawm cov hlab ntsha sib xyaw, vim li ntawd cov kub ua haujlwm yuav tsum tau qis tshaj 315 ℃. Qhov hom hlau no tsuas yog siv los ua khoom tsim rau cov cuab yeej aerospace, kev siab siab cov hlab ntsha thiab cov khoom siv tshuaj uas muaj qhov siab ntxhov siab heev.