Tempered iav Kev ntsuas kub ceev

Zoo
Tempered iav yog tau los ntawm kev txiav cov iav annealed zoo tib yam rau hauv qhov xav tau loj, ces cua sov nws mus rau qhov chaw ze ntawm qhov muag, thiab tom qab ntawd txias nws sai thiab sib npaug. Tom qab tempering, uniform compressive kev nyuaj siab yog tsim nyob rau saum npoo ntawm iav, thaum tensile kev nyuaj siab yog tsim nyob rau hauv, uas zoo heev txhim kho cov kev ua tau zoo ntawm iav. Lub zog tensile yog ntau tshaj 3 npaug ntawm qhov kawg, thiab qhov cuam tshuam tsis kam yog ntau tshaj 5 npaug ntawm tom kawg.
Nws yog qhov tseeb tias cov yam ntxwv kev ntxhov siab dhau los ua ib qho tseem ceeb rau kev paub qhov tseeb thiab tsis tseeb tempered iav, uas yog, tempered iav tuaj yeem pom cov xim kab txaij ntawm ntug ntawm iav los ntawm cov yeeb yaj kiab polarizing, thiab cov xim dub thiab dawb tuaj yeem pom ntawm lub ntsej muag. nto ntawm iav. Polarizing films tuaj yeem pom hauv lub koob yees duab lo ntsiab muag lossis tsom iav. Ua tib zoo saib xyuas qhov kev hloov ntawm lub teeb ci thaum saib, kom nws yooj yim rau kev soj ntsuam.
Self-explosion defect
Qhov tsis siv neeg tawg ntawm tempered iav yam tsis muaj kev siv hluav taws xob ncaj qha sab nraud yog hu ua tus kheej tawg ntawm tempered iav. Raws li kev lag luam kev paub, tus kheej tawg tus nqi ntawm cov iav tempered zoo tib yam yog li 1 ~ 3‰. Kev tawg tus kheej yog ib qho ntawm cov yam ntxwv ntawm cov iav tempered.
Muaj ntau ntau qhov laj thawj rau kev nthuav dav ntawm kev tawg tshwm sim, uas tuaj yeem sau tau yooj yim raws li hauv qab no:
① Kev cuam tshuam ntawm iav tsis zoo
A. Muaj cov pob zeb, impurities thiab npuas hauv iav: impurities hauv iav yog cov ntsiab lus tsis muaj zog ntawm tempered iav thiab cov ntsiab lus kev ntxhov siab. Tshwj xeeb, yog tias cov pob zeb nyob hauv thaj tsam tensile stress of tempered iav, nws yog ib qho tseem ceeb uas ua rau tawg.
Cov pob zeb muaj nyob hauv lub khob thiab muaj qhov sib txawv ntawm qhov sib txawv ntawm cov iav lub cev. Tom qab lub iav yog tempered, qhov kev ntxhov siab concentration nyob rau hauv qhov chaw tawg nyob ib ncig ntawm lub pob zeb nce exponentially. Thaum lub expansion coefficient ntawm lub pob zeb yog me dua li ntawm cov iav, lub tangential kev nyuaj siab nyob ib ncig ntawm lub pob zeb yog nyob rau hauv lub tensile lub xeev. Kev nthuav dav nrog pob zeb yog qhov yooj yim heev los tshwm sim.
B. Nickel sulfide crystals nyob rau hauv lub khob
Nickel sulfide inclusions feem ntau muaj nyob rau hauv me me siv lead ua spheres nrog ib txoj kab uas hla ntawm 0 1-2 hli. Cov tsos yog xim hlau. Cov kev suav no yog Ni3S2, Ni7S6 thiab Ni-XS, qhov twg X=0-0.07. Tsuas yog Ni1-XS theem yog qhov laj thawj tseem ceeb ntawm kev tawg ntawm cov iav tempered.
Lub theoretical NIS paub tias yog 379. C, muaj cov txheej txheem hloov mus rau theem, los ntawm qhov kub-kub -NiS hexagonal system mus rau qhov qis-kub-NiS trigonal system, nrog rau 2.38% ntim expansion. Cov qauv no yog khaws cia ntawm chav tsev kub. Yog hais tias lub iav yog rhuab nyob rau hauv lub neej yav tom ntej, lub - lub xeev yuav sai sai hloov. Yog hais tias cov impurities nyob rau hauv lub tempered iav nyob rau hauv tensile kev nyuaj siab, lub ntim expansion yuav ua rau spontaneous cracking. Yog tias muaj a-NIS nyob hauv chav sov, nws yuav maj mam hloov mus rau lub xeev tom qab ob peb xyoos lossis ntau lub hlis. Qhov nce qeeb hauv ntim thaum lub sijhawm hloov pauv no yuav tsis ua rau sab hauv rupture.
C. Cov iav nto muaj khawb, tawg, sib sib zog nqus tawg thiab lwm yam tsis xws luag vim yog kev ua haujlwm tsis zoo lossis kev ua haujlwm, uas tuaj yeem ua rau muaj kev ntxhov siab los yog ua rau cov iav tempered tawg.
② Tsis sib xws thiab offset kev nyuaj siab faib nyob rau hauv tempered iav
Qhov kub gradient generated raws lub thickness ntawm cov iav thaum rhuab los yog txias tsis sib xws thiab asymmetrical. Cov khoom tempered zoo li tawg los ntawm nws tus kheej, thiab qee qhov tsim "cua tawg" thaum quenching. Yog hais tias qhov tensile stress area deviates rau ib sab ntawm cov khoom los yog rau saum npoo, tempered iav yuav tawg los ntawm nws tus kheej.
③ Kev cuam tshuam ntawm cov degree ntawm toughening. Cov kev sim tau pom tias thaum qhov kev sib tw toughening nce mus rau 1 qib / cm, tus naj npawb ntawm tus kheej tawg mus txog 20% ​​~ 25%. Qhov no qhia tau hais tias qhov kev ntxhov siab ntau dua, qhov siab dua ntawm qhov toughening, thiab ntau dua qhov kev tawg ntawm tus kheej.