硅鐵就是鐵(tie)和硅(gui)(gui)(gui)(gui)組成(cheng)的鐵(tie)合(he)(he)金(jin)。 硅(gui)(gui)(gui)(gui)鐵(tie)是以焦炭、鋼(gang)(gang)屑、石英（或硅(gui)(gui)(gui)(gui)石）為原料，用電爐冶煉(lian)制成(cheng)的鐵(tie)硅(gui)(gui)(gui)(gui)合(he)(he)金(jin)。由(you)于(yu)(yu)硅(gui)(gui)(gui)(gui)和氧(yang)很容易化合(he)(he)成(cheng)二氧(yang)化硅(gui)(gui)(gui)(gui)，所以硅(gui)(gui)(gui)(gui)鐵(tie)常(chang)用于(yu)(yu)煉(lian)鋼(gang)(gang)時(shi)作(zuo)脫氧(yang)劑，同(tong)時(shi)由(you)于(yu)(yu)SiO2生成(cheng)時(shi)放(fang)出大(da)量的熱，在(zai)脫氧(yang)的同(tong)時(shi)，對(dui)提(ti)高鋼(gang)(gang)水溫度也是有利的。同(tong)時(shi)，硅(gui)(gui)(gui)(gui)鐵(tie)還(huan)可作(zuo)為合(he)(he)金(jin)元(yuan)素加入(ru)劑，廣泛應用于(yu)(yu)低(di)合(he)(he)金(jin)結構鋼(gang)(gang)、彈簧鋼(gang)(gang)、軸承鋼(gang)(gang)、耐熱鋼(gang)(gang)及電工硅(gui)(gui)(gui)(gui)鋼(gang)(gang)之中(zhong)，硅(gui)(gui)(gui)(gui)鐵(tie)在(zai)鐵(tie)合(he)(he)金(jin)生產及化學工業中(zhong)，常(chang)用作(zuo)還(huan)原劑。

硅鐵是(shi)煉鋼工(gong)(gong)業(ye)中(zhong)(zhong)(zhong)(zhong)必(bi)不可少的(de)(de)(de)脫(tuo)氧(yang)劑。炬鋼中(zhong)(zhong)(zhong)(zhong)，硅(gui)(gui)(gui)鐵(tie)(tie)(tie)用(yong)于沉(chen)淀(dian)脫(tuo)氧(yang)和(he)擴散(san)脫(tuo)氧(yang)。磚坯鐵(tie)(tie)(tie)還(huan)作(zuo)為合金(jin)劑用(yong)于煉鋼中(zhong)(zhong)(zhong)(zhong)。鋼中(zhong)(zhong)(zhong)(zhong)添加一定數量的(de)(de)(de)硅(gui)(gui)(gui)，能(neng)顯(xian)著提(ti)高鋼的(de)(de)(de)強度(du)、硬度(du)和(he)彈性，提(ti)高鋼的(de)(de)(de)磁(ci)導率，降低變(bian)壓(ya)器(qi)鋼的(de)(de)(de)磁(ci)滯(zhi)損耗。一般鋼中(zhong)(zhong)(zhong)(zhong)含(han)硅(gui)(gui)(gui)0.15%-0.35%，結(jie)構鋼中(zhong)(zhong)(zhong)(zhong)含(han)硅(gui)(gui)(gui)0.40%～1.75%，工(gong)(gong)具鋼中(zhong)(zhong)(zhong)(zhong)含(han)硅(gui)(gui)(gui)0.30%～1.80%，彈簧鋼中(zhong)(zhong)(zhong)(zhong)含(han)硅(gui)(gui)(gui)0.40%～2.80%，不銹耐酸鋼中(zhong)(zhong)(zhong)(zhong)含(han)硅(gui)(gui)(gui)3.40%～4.00%，耐熱鋼中(zhong)(zhong)(zhong)(zhong)含(han)硅(gui)(gui)(gui)1.00%～3.00%，硅(gui)(gui)(gui)鋼中(zhong)(zhong)(zhong)(zhong)含(han)硅(gui)(gui)(gui)2%～3%或(huo)更(geng)高。高硅(gui)(gui)(gui)硅(gui)(gui)(gui)鐵(tie)(tie)(tie)或(huo)硅(gui)(gui)(gui)質合金(jin)在鐵(tie)(tie)(tie)合金(jin)工(gong)(gong)業(ye)中(zhong)(zhong)(zhong)(zhong)用(yong)作(zuo)生(sheng)產低碳鐵(tie)(tie)(tie)合金(jin)的(de)(de)(de)還(huan)原(yuan)劑。硅(gui)(gui)(gui)鐵(tie)(tie)(tie)加入(ru)鑄鐵(tie)(tie)(tie)中(zhong)(zhong)(zhong)(zhong)可作(zuo)球墨鑄鐵(tie)(tie)(tie)的(de)(de)(de)孕(yun)育劑，且(qie)能(neng)阻止碳化物形成，促進石墨的(de)(de)(de)析出和(he)球化，改善鑄鐵(tie)(tie)(tie)性能(neng)。

在(zai)煉鋼工(gong)業中(zhong)，每生產一噸鋼大約消耗3～5kg75%硅(gui)鐵(tie)。熔點：75FeSi為(wei)1300℃,在(zai)煉鋼工(gong)業中(zhong)，硅(gui)鐵(tie)中(zhong)含有少(shao)量磷(lin)的(de)金屬(shu)化(hua)(hua)合物，如(ru)磷(lin)化(hua)(hua)鈣等，在(zai)車船運輸(shu)或倉庫儲存(cun)時，如(ru)果受潮，可(ke)放出磷(lin)化(hua)(hua)氫，使倉內或周圍人群中(zhong)毒。磷(lin)化(hua)(hua)氫中(zhong)毒嚴重時可(ke)致人死亡。