Temper brittleness, raws li ib qho tshwm sim tshwm sim thaum lub sij hawm kho cua sov hlau, muaj kev cuam tshuam tseem ceeb rau cov khoom siv hluav taws xob, tshwj xeeb tshaj yog cuam tshuam rau cov tawv nqaij. Kab lus no yuav pib los ntawm lub ntsiab lus tseem ceeb ntawm temper brittleness, sib tham txog nws qhov kev tsim ua kom ntxaws, thiab qhia txog cov txheej txheem tiv thaiv.
1. Lub tswv yim tseem ceeb ntawm kev npau taws brittleness
Temper brittleness, raws li lub npe qhia, yog hais txog embrittlement phenomenon uas tshwm sim thaum hlau yog tempered tom qab quenching. Raws li tempering kub ntau yam uas ua rau brittleness, temper brittleness yuav muab faib ua low-temperature brittleness thiab high-temperature brittleness. Tsawg kub temper brittleness, tseem hu ua thawj hom temper brittleness, feem ntau tshwm sim nyob rau hauv qhov kub ntawm 250 mus rau 400 degree; thaum kub kub temper brittleness, tseem hu ua ob hom temper brittleness, feem ntau tshwm sim nyob rau hauv qhov kub ntawm 450 mus rau 650 degree.
2. Ua rau npau taws
a. Tsawg kub temper brittleness (hom 1 temper brittleness)
Cov laj thawj rau kev tsim ntawm qhov kub thiab txias ntawm qhov brittleness yog qhov nyuaj. Tam sim no, feem ntau yog cov theories hauv qab no:
• Khaws austenite transformation txoj kev xav: Nws ntseeg tau tias qhov kub tsis tshua muaj qhov kub thiab txias yog tshwm sim thaum khaws austenite hloov mus rau hauv tempered martensite los yog bainite thaum lub sij hawm tempering.
• Carbide nag lossis daus txoj kev xav: Nws ntseeg tau tias qhov kub thiab txias ntawm qhov brittleness yog vim nag lossis daus ntawm flake carbides los ntawm martensite. Cov carbides precipitate nyob rau hauv lub interface ntawm martensite strips los yog cov nplooj ntawv, txo cov pob txha lub zog ntawm cov lis ciam teb thiab tig lawv mus rau hauv cov kab nrib pleb. Kev nthuav dav.
• impurity segregation txoj kev xav: Nws ntseeg tau tias qhov kub thiab txias yog vim muaj kev sib cais ntawm impurity hauv cov hlau xws li phosphorus, sulfur, arsenic, tin, antimony, thiab lwm yam ntawm qhov qub austenite grain ciam teb, uas ua rau cov tsis muaj zog. cov qoob loo ciam teb.
b. Kub kub kub brittleness (ob hom temper brittleness)
Qhov ua rau kub kub kub brittleness yog qhov tseeb, feem ntau yog vim muaj kev sib cais ntawm cov kab tsis huv (xws li phosphorus, tin, antimony, arsenic, thiab lwm yam) los yog cov ntsiab lus alloying hauv cov hlau mus rau qhov qub austenite grain ciam teb thaum lub sij hawm tempering. txheej txheem. Kev sib cais ntawm cov ntsiab lus ntawm cov ciam teb nplej txo cov pob txha muaj zog ntawm cov ciam teb, ua rau nkig tawg. Tsis tas li ntawd, cov ntsiab lus alloying xws li npib tsib xee, chromium, manganese, thiab lwm yam tseem yuav txhawb kev sib cais ntawm impurity ntsiab, ntxiv aggravating lub embrittlement phenomenon.
Nws tuaj yeem pom los ntawm daim duab 1 tias thaum lub sij hawm tempering ntawm 30Ni-Cr steel, raws li tempering kub nce, qhov cuam tshuam toughness mus txog qhov tsawg kawg nkaus tus nqi ntawm 300 degree thiab 550 degree. Thawj hom temper brittleness tshwm nyob ze 300 degree . Tom qab hom temper brittleness tshwm sim, temper nws ntawm qhov kub siab tshaj los yog sib npaug rau 300 degree kom tsis txhob muaj qhov kub thiab txias ntau yam thiab rov ua kom nws tawv; Yog hais tias nws yog dua nyob rau hauv thaj tsam ntawm 250 ~ 400 degree Internal tempering yuav tsis txo cov toughness ntawm cov khoom, yog li nws yuav pom tau hais tias thawj hom temper brittleness yog irreversible. Raws li tau pom los ntawm daim duab 1, qhov thib ob hom temper brittleness tshwm nyob ze 500 degree; Tom qab tempering ntawm qhov kub siab tshaj los yog sib npaug rau 650 degree, txias maj mam thiab nyob ntawm 500 ~ 650 degree rau ib lub sij hawm ntev kuj yuav ua rau embrittlement, thaum txias ceev yuav tsis Embrittlement yuav tshwm sim, raws li qhia nyob rau hauv daim duab 1. Tom qab lub brittleness ntawm cov khoom uas ua rau ob hom temper brittleness yog tshem tawm, yog hais tias nws yog rhuab mus rau lub brittle kub ntau dua, los yog yog hais tias nws yog maj mam txias nyob rau hauv lub brittleness rau lub sij hawm ntev, lub brittleness yuav rov tshwm sim. Nws tuaj yeem pom tias hom thib ob ntawm temper brittleness yog thim rov qab.
3. Cov txheej txheem los tiv thaiv temper brittleness
a. Cov txheej txheem los tiv thaiv kom tsis txhob kub kub brittleness
• Txo cov ntsiab lus ntawm impurity ntsiab nyob rau hauv steel: Txo cov ntsiab lus ntawm phosphorus, sulfur, arsenic, tin, antimony thiab lwm yam impurity ntsiab nyob rau hauv steel los ntawm refining thiab lwm yam txheej txheem yuav fundamentally txo qhov kev pheej hmoo ntawm low-temperature brittleness.
• Ntxiv cov ntsiab lus uas ua kom zoo austenite nplej: xws li niobium (Nb), vanadium (V), titanium (Ti), thiab lwm yam, tuaj yeem ua kom zoo austenite nplej thiab ua rau thaj tsam ntawm cov qoob loo, yog li txo cov impurity cov ntsiab lus hauv ib cheeb tsam ntawm kev sib cais. .
• Kho cov txheej txheem tempering: Siv isothermal quenching es tsis txhob quenching thiab high-temperature tempering txheej txheem yuav ua tau zoo kom tsis txhob muaj qhov tshwm sim ntawm low-temperature brittleness.
• Alloying: Ntxiv cov nqi tsim nyog ntawm molybdenum (Mo), tungsten (W) thiab lwm yam alloying ntsiab tuaj yeem txo qhov kub thiab txias ntawm brittleness. Nyob rau tib lub sijhawm, cov khoom xws li silicon (Si) thiab chromium (Cr) kuj tuaj yeem kho qhov kub thiab txias qhov twg qhov kub ntawm qhov brittleness tshwm sim kom tsis txhob muaj qhov kub thiab txias.
