Cov ntsiab lus "quenched thiab tempered" (Q&T) thiab "siab- zog" yog cov lus piav qhia meej ntawm nws lub xeev metallurgical thiab cov txheej txheem kev lag luam tshwj xeeb siv los ua kom tiav.
1. Vim li cas thiaj hu ua "Quenched and Tempered High-Strength Steel"
Lub npe no yog cov ntsiab lus ncaj qha ntawm nws cov yam ntxwv tseem ceeb thiab nws txoj kev tsim khoom.
"High-Strength": Qhov no yog nws qhov kev ua haujlwm tseem ceeb. Nrog rau qhov tsawg kawg nkaus lub zog ntawm 890 MPa (≈129 ksi), nws belongs rau qeb ntawm Ultra-High-Strength Steels (UHSS). Nws lub zog yog 2.5 npaug ntawm cov qauv hlau (S355), ua kom sib dua, tsim tau zoo dua.
"Quenched thiab Tempered": Qhov no yog txoj kev tshwj xeeb uas qhov tshwj xeeb lub zog, ua ke nrog txaus toughness, tiav. Nws tsis yog muaj zog xwb; nws muaj zog vim nws tau quenched thiab tempered. Cov txheej txheem no txawv nws los ntawm lwm cov high- steels muaj zog uas tau txais lub zog los ntawm kev sib txawv (xws li, ua haujlwm txias, nag lossis daus hardening hauv micro- alloyed steels).
2. Tus Txheej Txheem Tsim Nyog: Ib Ob -Thermal Mastery
Cov txheej txheem Q&T yog ib qho kev tswj xyuas meej ntawm cov cua sov thiab cua txias uas hloov cov hlau sab hauv microstructure. Rau S890QL1, cov txheej txheem no nruj me ntsis raws li cov qauv zoo li EN 10025-6.
Ntawm no yog cov kauj ruam -los ntawm - kauj ruam tawg:
Kauj Ruam 1: Quenching (Theem "Hardening")
Lub Hom Phiaj: Yuav kom tsim tau ib qho nyuaj heev, tab sis ntau dhau nkig, microstructure thoob plaws tag nrho cov thickness ntawm steel phaj.
Txheej txheem:
Austenitizing: Cov phaj hlau yog rhuab mus rau qhov kub thiab txias (feem ntau yog 880℃- 950℃) hauv qhov cub. Ntawm qhov kub no, nws cov microstructure hloov pauv tag nrho rau hauv cov tshuaj hu ua austenite, thiab tag nrho cov ntsiab lus alloying dissolve uniformly.
Kev ua kom txias sai sai (Quenching): Lub phaj yuav raug tshem tawm sai sai ntawm lub qhov cub thiab txias ntawm tus nqi siab, feem ntau yog txau nrog siab - cov dav hlau dej siab los yog raus hauv cov tshuaj polymer. Qhov txias txias no "freezes" cov qauv austenitic, tiv thaiv nws los ntawm kev hloov mus rau hauv lub softer theem (ferrite, pearlite) uas tsim thaum lub sij hawm qeeb txias.
Ua rau Microstructure: Lub austenite hloov mus rau hauv martensite - ib qho ultra- tawv, koob- zoo li cov qauv siv lead ua. Qhov no martensite muab cov hlau nws lub hauv paus siab zog tab sis yog intrinsically brittle thiab nquag tawg.
Theem 2: Tempering (Theem "Toughening")
Lub Hom Phiaj: Txhawm rau pauv tus nqi tswj hwm ntawm qhov nyuaj / lub zog los ntawm quenching rau kev nce siab hauv toughness, ductility, thiab dimensional stability, ua rau cov hlau siv tau hauv kev siv engineering.
Txheej txheem:
Reheating: Lub phaj tag nrho quenched (nkig) yog reheated rau ib tug ua tib zoo xaiv sub- kub tseem ceeb, feem ntau nyob rau hauv thaj tsam ntawm 550℃mus rau 650℃. Qhov kub no yog qis dua qhov chaw uas austenite rov ua dua tab sis siab txaus kom tso cai rau atomic txav.
Soaking: Lub phaj tuav ntawm qhov ntsuas kub no rau lub sijhawm xam (nyob ntawm qhov tuab), tso cai rau kev hloov pauv ntawm cov hlau:
Stress Relief: Sab hauv kev ntxhov siab los ntawm quenching raug txo.
Carbide Precipitation: Cov pa roj carbon ntau nyob rau hauv martensite zoo, dispersed carbide hais (xws li, ntawm vanadium, molybdenum). Qhov no yog ib qho tseem ceeb ntxiv zog mechanism.
Microstructure Transformation: Lub nkig martensite hloov mus rau hauv cov ntaub ntawv ntau dua thiab tawv microstructure hu ua tempered martensite lossis tempered bainite.
Tswj Cooling: Lub phaj yog ces txias, feem ntau nyob rau hauv tseem huab cua.
Qhov tshwm sim Microstructure: Tempered Martensite. Cov qauv no khaws cov qib siab zog heev (890 MPa tawm los) tab sis tam sim no muaj cov ductility txaus thiab, qhov tseem ceeb tshaj plaws rau S890QL1, qhov cuam tshuam toughness yuav tsum tau ua kom tau raws li "-60℃(L1)" specification.
3. Lub luag haujlwm ntawm cov tshuaj lom neeg
Cov txheej txheem Q&T tsuas yog siv tau vim yog S890QL1 qhov tshwj xeeb, lean alloy tsim:
Tsawg Carbon (~ 0.15-0.18%): Muab hardenability rau martensite tsim thaum tuav zoo weldability.
Alloying Elements (Mn, Cr, Ni, Mo, B, V): Cov no yog cov "enablers."
Hardenability Enhancers (B, Mn, Cr, Mo): Xyuas kom lub martensitic transformation tshwm sim txawm nyob rau hauv cov tub ntxhais ntawm tuab daim hlau thaum lub sij hawm quench.
Toughness Enhancer (Ni): Qhov tseem ceeb rau kev ua tiav qhov qis -kub (-60 degree) toughness.
Precipitation Strengtheners (V, Mo): Ua kom zoo carbides thaum lub sij hawm tempering, pab txhawb rau qhov kawg siab zog.
Synthesis: "Q" hauv S890QL1
Lub "Q" nyob rau hauv lub npe qib yog lub npe nom tswv rau qhov tseeb Quenched thiab Tempered mob raws li EN 10025-6. Nws yog ib qho kev lees paub tias cov phaj hlau uas koj tau txais tau dhau los no sophisticated, lub zog - hnyav, thiab nruj tswj ob-theem kev kho cua sov.
Hauv cov ntsiab lus:S890QL1 yog hu ua "quenched thiab tempered siab- lub zog steel" vim tias nws qhov sib txawv tsis sib xws ntawm 890 MPa yield zog thiab -60℃toughness yog cov khoom ncaj nraim, tsis sib cais ntawm quench-thiab-temper manufacturing txheej txheem. Cov txheej txheem no yog qhov hloov pauv cov tshuaj lom neeg zoo tib yam rau hauv cov khoom siv engineering tshwj xeeb.