T91 qib steel muaj ntau qhov zoo sib xws, xws li kev ua haujlwm zoo hauv chav kub thiab kev nkag siab zoo, tsis tshua muaj coefficient ntawm linear expansion, qis nqi (9.5-11.5% alloy) thiab kev ruaj ntseg zoo hauv lub sijhawm ntev, yog li nws tau ua cov khoom siv tsis tau ntawm boiler steel raj siv rau ultra-siab tseem ceeb heev zog fais fab nroj tsuag.
Alloyed nrog yuav luag 9% chromium thiab 1% molybdenum, lawv tseem hu ua 9 Cr 1 Mo steel vim lawv muaj pes tsawg leeg. T91 steel muaj ib tug banded martensite theem nyob rau hauv kub dov tej yam kev mob uas ua kom muaj zog dua hardness, yog li yuav tsum tau tempering kho kom txo tau lub hardness kom tau zoo machinability. Lub recrystallization kub ntawm T91 steel yog ntau tshaj 790. Tsis tshua muaj temper kub yuav luag tsis muaj kev cuam tshuam rau cov microstructures thiab cov khoom ntawm T91 steel, thaum kub tempering yuav ua rau lub recrystallization lub koom haum tsim ferrite theem thiab tsis sib xws lub koom haum.
Tsis ntev los no, ib tus kws tshaj lij los ntawm Tuam Tshoj tau ua ib qho kev sim los ntawm kev soj ntsuam ntawm metallography, scanning electron microscopy thiab microhardness test, kawm txog cov qauv thiab hardness ntawm qhov sib txawv tempering kub (300 ~ 780), thiab tempered tus nqi txias ntawm T91 steel. Cov txiaj ntsig tau pom tias qhov hardness hauv qab 300 ~ 400 tau hloov me ntsis; Hauv qab 500 ~ 600℃yog rau thaj tsam rhiab heev rau carbide nag lossis daus qhov twg ntau cov carbide dispersion precipitates hauv matrix, nyob rau hauv cheeb tsam no, lub hardness yog siab dua thiab muaj ib tug upward sib; Thaum qhov kub nce ntawm 600 mus rau 780, cov carbide raws cov ciam teb yog zoo precipitated thiab lub hardness yog txo. Lub hardness maj mam txo thaum lub quenching quenching tus nqi nce, uas txo cov quenching npaum li cas los ntawm rhiab ntau ntawm 500 ~ 600 ntawm tus nqi ntawm 5℃/ min, nag lossis daus ntawm carbide dispersion thiab ntau dua tuag hardness; Los ntawm quenching thaum tshav kub kub preservation tsawg dua 780 thiab ceev txias npaum li cas (50℃/ min) tom qab lub txias txheej txheem, carbide nag lossis daus rhiab heev tshwm sim sai thiab tsawg nag lossis daus carbides nyob rau hauv lub matrix, qhov qis hardness thiab qhov zoo tshaj plaws kev ua tau zoo.
