Lub sij hawm 'silicon hlau' yog siv los piav txog cov alloys uas muaj silicon ua lub ntsiab alloying, uas feem ntau siv nyob rau hauv foundries. Qhov sib ntxiv ntawm silicon rau cov alloys no ua rau kev txhim kho flowability, kub cracking kuj thiab nruj. Lwm cov ntsiab lus xws li tooj liab thiab magnesium yog ntxiv los txhim kho lub zog ntawm cov khoom thaum kho cua sov.
Lub luag haujlwm ntawm silicon hlau hauv steel ntau lawm yog multifaceted.
(a) Ib qho ntawm nws txoj haujlwm tseem ceeb yog deoxidation. Silicon yog lub zog deoxidising tus neeg sawv cev uas tuaj yeem ua ke nrog cov pa oxygen hauv cov hlau molten los ua SiO₂ slag, yog li txo cov pa oxygen ntawm cov hlau.
b) nce melting point: Qhov sib ntxiv ntawm silicon hlau tuaj yeem ua rau me ntsis nce ntawm cov hlau melting, uas yog qhov tseem ceeb hauv qee qhov kev siv kub.
c) Txhawb graphitisation: Hauv cam khwb cia hlau, muaj cov hlau silicon tuaj yeem txhawb kev tsim graphite, cuam tshuam rau cov qauv thiab cov khoom ntawm cov hlau.