Cov hlau nplaum yog qhov zoo tagnrho rau cov ntaub ntawv valve, vim nws muaj ntau yam zoo.Raws li kev hloov pauv rau cov hlau, cov hlau nplaum tau tsim nyob rau xyoo 1949. Cov ntsiab lus ntawm cov hlau cam khwb cia yog tsawg dua 0.3%, thaum cov hlau cam khwb cia thiab cov hlau ductile yog tsawg kawg yog 3%.Cov pa roj carbon tsawg ntawm cov hlau cam khwb cia ua rau cov pa roj carbon uas twb muaj lawm ua cov graphite dawb tsis tsim flakes.Lub ntuj daim ntawv ntawm carbon nyob rau hauv cam khwb cia hlau yog dawb graphite flakes.Hauv cov hlau nplaum, graphite yog nyob rau hauv daim ntawv ntawm nodules es tsis yog flakes li cam khwb cia hlau.Piv nrog cam khwb cia hlau thiab cam khwb cia hlau, ductile hlau muaj lub cev zoo dua.Nws yog qhov sib npaug nodules uas inhibit qhov kev tsim ntawm cov kab nrib pleb, yog li muab qhov kev txhim kho ductility uas muab cov hlau nws lub npe.Txawm li cas los xij, lub flake nyob rau hauv cam khwb cia hlau ua rau tsis muaj ductility ntawm cov hlau.Qhov zoo tshaj plaws ductility tuaj yeem tau txais los ntawm ferrite matrix.

Piv nrog cov hlau cam khwb cia, cov hlau nplaum muaj qhov zoo ntawm lub zog.Lub zog tensile ntawm cov hlau nplaum yog 60k, thaum cov hlau cam khwb cia tsuas yog 31k.Lub zog ntawm cov hlau nplaum yog 40k, tab sis cov hlau cam khwb cia tsis qhia lub zog tawm los thiab yuav tawg thaum kawg.

Lub zog ntawm ductile hlau yog piv rau cov cam khwb cia hlau.Ductile hlau muaj zog dua tawm los.Qhov qis tshaj tawm lub zog ntawm cov hlau nplaum yog 40k, thaum lub zog ntawm cov hlau cam khwb cia tsuas yog 36k.Hauv cov ntawv thov hauv nroog feem ntau, xws li dej, dej ntsev, chav dej, kev tiv thaiv corrosion thiab oxidation tsis kam ntawm cov hlau ductile yog superior rau cov hlau cam khwb cia.Ductile hlau tseem hu ua spheroidal graphite hlau.Vim hais tias ntawm spheroidal graphite microstructure, cov hlau ductile yog superior rau cam khwb cia hlau nyob rau hauv dampening vibration, yog li nws yog ntau conducive rau txo kev ntxhov siab.Ib qho laj thawj tseem ceeb rau kev xaiv cov hlau nplaum raws li cov khoom siv valve yog tias nws muaj nqi qis dua cov hlau cam.Tus nqi qis ntawm cov hlau nplaum ua rau cov khoom siv no nrov dua.Tsis tas li ntawd, xaiv cov hlau ductile tuaj yeem txo tus nqi machining.