Austempered ductile hlau, tseem hu ua ADI, hais txog cov hlau cam khwb cia hlau tom qab txheej txheem ntawm austenitizing ductile hlau (850 ℃ -950 ℃) thiab tom qab ntawd muab tso rau hauv ntsev da dej (232 ℃ - 450 ℃) rau isothermal transformation. Tsis tas li ntawd, nrog rau qhov sib ntxiv ntawm cov nyiaj txaus ntawm Cu, Ni, Mo thiab lwm yam khoom, austempered austenitic ductile hlau kuj tuaj yeem tau txais nyob rau hauv qhov txias txias.
Austempered ductile hlaucastingsmuaj cov khoom siv kho tshuab zoo heev, thiab lawv chav ntsuas qhov hnyav ntawm lub zog tawm los yog qhov tsawg tshaj plaws. Kev tau txais cov qib sib txawv ntawm austempered ductile hlau nyob ntawm qhov kub ntawm austempering thiab tsis muaj dab tsi cuam tshuam nrog cov tshuaj muaj pes tsawg leeg. Feem ntau hais lus, cov tshuaj muaj pes tsawg leeg ntawm austempered ductile hlau yog nyob rau hauv ntau yam hauv qab no:
C: 3.5% -3.8%
Qhov hnyav: 2.4% - 3.0%
Mn: ± 0.30%
P: <0.07%
S: <0.02%
Silicon yog ib qho tseem ceeb tshaj plaws ntawm austempered ductile hlau. Silicon tiv thaiv kev tsim ntawm Bainite carbides, yog li pab tsim cov acicular ferrite. Ua kom cov ntsiab lus silicon tuaj yeem ua rau muaj kev cuam tshuam toughness ntawm austempered ductile cam khwb cia hlau thiab txo elongation. Lub luag haujlwm ntawm Manganese muaj ob sab. Ntawm ib sab, nws tuaj yeem txhim kho qhov hardenability zoo heev; Ntawm qhov tod tes, Manganese yuav txhawb kev tsim cov carbides thiab cuam tshuam cov isothermal transformation thaum lub sij hawm solidification txheej txheem. Yog li ntawd, thaum tus naj npawb ntawm graphite spheres qis thiab phab ntsa tuab loj, kev sib cais ntawm manganese ntawm cov ciam teb yuav ua rau shrinkage porosity, carbides thiab tsis ruaj tsis khov austenite hauv cov hlau casting. Cov microstructure defects thiab inhomogeneities yuav txo cov machinability thiab mechanical zog. Yog li ntawd, qhov loj feem pua ntawm manganese yuav tsum tau tswj qis dua 3%.
Nyob rau hauv qhov tseeb casting ntau lawm, nyob rau hauv thiaj li yuav tau ruaj khov thiab zoo austemperedhlau castings, muaj ob lub ntsiab lus uas xav tau kev saib xyuas tshwj xeeb:
1) Tswj cov qauv ntawm as-cam khwb cia hlau hlau ua ntej isothermal kho. Tus nqi spheroidization yuav tsum siab tshaj 80%. Tus naj npawb ntawm graphite pheres yuav tsum ntau tshaj 100 ib square millimeter. Lwm yam mob muaj xws li: ruaj khov tshuaj muaj pes tsawg leeg; lub casting yuav tsum tsis muaj carbide, porosity thiab inclusions; thiab ruaj khov pearlite / ferrite cov ntsiab lus piv.
2) Txiav txim siab qhov tsim nyog kev kho cua sov specifications raws li muaj pes tsawg leeg thiab raws li-cam khwb cia hlau ductile hlau, thiab ua ib tug nruj thiab ruaj khov austempering cua sov txheej txheem
Lub sij hawm xa tuaj: Plaub Hlis-15-2021