一、石墨電極是什么東西
石墨電極是一種耐高溫石墨質導電材料(liao),是在電弧(hu)爐(lu)中以電弧(hu)形式釋(shi)放電能對爐(lu)料(liao)進行加熱熔(rong)化的導體,作為銅電極的代替品之一。
石(shi)墨電(dian)極主要有(you)天然石(shi)墨電(dian)極和(he)人造石(shi)墨電(dian)極兩種,其中(zhong)應用比較廣泛的是人造石(shi)墨電(dian)極,是以石(shi)油(you)焦(jiao)、瀝青焦(jiao)為骨料,煤瀝青為黏結劑(ji),經過原(yuan)料煅(duan)燒(shao)、破碎磨粉、配料、混捏(nie)、成型(xing)、焙燒(shao)、浸漬、石(shi)墨化和(he)機(ji)械(xie)加(jia)工而制成的。
二、石墨電極的用途和性能
石(shi)墨電極作(zuo)為一種化學材料,其具體良好的性(xing)能,因此(ci)應用也比(bi)較(jiao)廣泛,下(xia)面(mian)為大家介紹以下(xia)石(shi)墨電極的用途和性(xing)能:
1、石墨電極的用途
(1)用(yong)于電(dian)弧煉(lian)(lian)鋼(gang)爐(lu):電(dian)爐(lu)煉(lian)(lian)鋼(gang)是石(shi)墨(mo)電(dian)極的(de)使用(yong)大戶(hu)。我國電(dian)爐(lu)鋼(gang)產量(liang)約占粗鋼(gang)產量(liang)的(de)18%左右(you),煉(lian)(lian)鋼(gang)用(yong)石(shi)墨(mo)電(dian)極占石(shi)墨(mo)電(dian)極總用(yong)量(liang)的(de)70%~80%。電(dian)爐(lu)煉(lian)(lian)鋼(gang)是利用(yong)石(shi)墨(mo)電(dian)極向爐(lu)內導入電(dian)流,利用(yong)電(dian)極端部和爐(lu)料(liao)之間引(yin)發電(dian)弧所產生的(de)高(gao)溫熱源來進(jin)行冶煉(lian)(lian)。
(2)用于(yu)礦(kuang)熱(re)(re)電(dian)(dian)(dian)爐(lu):礦(kuang)熱(re)(re)電(dian)(dian)(dian)爐(lu)主要用于(yu)生(sheng)產(chan)(chan)工業硅(gui)(gui)和黃磷等,其(qi)特點是(shi)導電(dian)(dian)(dian)電(dian)(dian)(dian)極(ji)(ji)的(de)下部埋在爐(lu)料中,在料層內形(xing)成(cheng)電(dian)(dian)(dian)弧,并利(li)用爐(lu)料自身的(de)電(dian)(dian)(dian)阻所發出的(de)熱(re)(re)能來加(jia)熱(re)(re)爐(lu)料,其(qi)中要求電(dian)(dian)(dian)流密度(du)較高的(de)礦(kuang)熱(re)(re)電(dian)(dian)(dian)爐(lu)需(xu)(xu)用石(shi)墨電(dian)(dian)(dian)極(ji)(ji),例(li)如每(mei)生(sheng)產(chan)(chan)1t硅(gui)(gui)需(xu)(xu)消耗(hao)石(shi)墨電(dian)(dian)(dian)極(ji)(ji)約100kg,每(mei)生(sheng)產(chan)(chan)1t黃磷需(xu)(xu)消耗(hao)石(shi)墨電(dian)(dian)(dian)極(ji)(ji)約40kg。
(3)用(yong)于電(dian)(dian)(dian)(dian)阻爐(lu)(lu):生產石墨制品的(de)石墨化(hua)爐(lu)(lu)、熔化(hua)玻璃(li)的(de)熔窯和生產碳(tan)化(hua)硅(gui)用(yong)的(de)電(dian)(dian)(dian)(dian)爐(lu)(lu)等都屬(shu)于電(dian)(dian)(dian)(dian)阻爐(lu)(lu),爐(lu)(lu)內所裝物料既是發(fa)熱電(dian)(dian)(dian)(dian)阻又是被加熱對象,通常,導電(dian)(dian)(dian)(dian)用(yong)的(de)石墨電(dian)(dian)(dian)(dian)極嵌(qian)入(ru)電(dian)(dian)(dian)(dian)阻爐(lu)(lu)端部的(de)爐(lu)(lu)頭(tou)墻中(zhong),用(yong)于此處的(de)石墨電(dian)(dian)(dian)(dian)極不連(lian)續消(xiao)耗。
(4)用于制備異型石(shi)墨(mo)產(chan)(chan)品(pin):石(shi)墨(mo)電(dian)極(ji)的(de)毛坯還用于加(jia)工成各種坩堝、模具、舟皿(min)和發熱體等異型石(shi)墨(mo)產(chan)(chan)品(pin)。例如,在(zai)石(shi)英玻(bo)璃行業,每生產(chan)(chan)1t電(dian)熔(rong)管,需用石(shi)墨(mo)電(dian)極(ji)坯料(liao)10t;每生產(chan)(chan)1t石(shi)英磚(zhuan),需消(xiao)耗石(shi)墨(mo)電(dian)極(ji)坯料(liao)100kg。
2、石墨電極的性能
(1)導電性、導熱性強。
(2)較高(gao)的抗(kang)熱振性能和化學穩定性能。
(3)具有(you)潤滑(hua)性(xing)和抗磨(mo)性(xing)。
(4)加工較容(rong)易,EDM(電火花)時金屬去除率高,石(shi)墨損耗小。
(5)石(shi)墨(mo)的比重(zhong)是銅的1/5,同等體(ti)積石(shi)墨(mo)的重(zhong)量(liang)相對銅要輕5倍(bei)。銅制作成的大型電(dian)極(ji)由于太重(zhong),在(zai)長期電(dian)火花時對EDM機(ji)床主軸精度非常不利。而石(shi)墨(mo)則不會,而且搬運也(ye)非常安全。
(6)石(shi)墨可(ke)以有很(hen)高的(de)加工速(su)度(du),一(yi)般(ban)石(shi)墨的(de)加工速(su)度(du)較普通金屬快3-5倍(bei)。而且(qie)選(xuan)擇硬度(du)合適的(de)刀具(ju)(ju)和石(shi)墨,可(ke)減少刀具(ju)(ju)的(de)磨損和電極的(de)損耗。