高頻淬火設備的四種淬火方法
高(gao)(gao)頻(pin)淬火設(she)備采用感(gan)應(ying)(ying)加熱(re),工(gong)(gong)(gong)程師解釋感(gan)應(ying)(ying)加熱(re)的原理是(shi):工(gong)(gong)(gong)件(jian)放到(dao)感(gan)應(ying)(ying)器內,感(gan)應(ying)(ying)器一般是(shi)輸入中頻(pin)或高(gao)(gao)頻(pin)交流電(Hz或更高(gao)(gao))的空心(xin)銅管。產生(sheng)交變(bian)磁場(chang)在工(gong)(gong)(gong)件(jian)中產生(sheng)出同頻(pin)率的感(gan)應(ying)(ying)電流,這種感(gan)應(ying)(ying)電流在工(gong)(gong)(gong)件(jian)的分布(bu)是(shi)不均勻的,在表(biao)面(mian)強,而在內部很弱,到(dao)心(xin)部接近于0,利用這個集膚效應(ying)(ying),可使工(gong)(gong)(gong)件(jian)表(biao)面(mian)迅(xun)速加熱(re),在幾秒鐘內表(biao)面(mian)溫度上升(sheng)到(dao)800-1000?C,而心(xin)部溫度升(sheng)高(gao)(gao)很小。那么高(gao)(gao)頻(pin)淬火設(she)備有哪(na)些淬火方法呢?
1、等(deng)溫(wen)淬(cui)火:等(deng)溫(wen)淬(cui)火可以顯著減少工(gong)(gong)件(jian)變形與(yu)開裂現象(xiang),合(he)適處理(li)復雜、精度要求高和重要機械零件(jian),如模具(ju)、刀具(ju)、齒(chi)輪。同分級(ji)淬(cui)火一(yi)樣,等(deng)溫(wen)淬(cui)火也(ye)只(zhi)能適用(yong)于尺寸較(jiao)小的(de)工(gong)(gong)件(jian)。中(zhong)高頻淬(cui)火設備應該根(gen)據你需(xu)要淬(cui)火的(de)工(gong)(gong)件(jian)來(lai)決定用(yong)哪(na)一(yi)種淬(cui)火方法,比如大(da)件(jian)的(de)、精確要求高的(de),可能就要用(yong)到等(deng)溫(wen)淬(cui)火方法。小件(jian)工(gong)(gong)具(ju)也(ye)可能用(yong)單(dan)介質(zhi)淬(cui)火來(lai)實現。
2、單介質淬火:單介質淬火的優點是操作簡便,但是只適用于小尺寸且形狀簡單的工件,淬火設備廠家對尺寸較大的(de)工(gong)件容(rong)易產生(sheng)較大的(de)變(bian)形(xing)與開裂。
3、雙介質(zhi)淬(cui)(cui)(cui)火(huo)(huo)(huo):雙介質(zhi)淬(cui)(cui)(cui)火(huo)(huo)(huo)是將(jiang)工(gong)件(jian)加(jia)熱(re)奧氏(shi)(shi)體化后先浸入(ru)冷卻能(neng)力(li)強的(de)介質(zhi),在即將(jiang)發(fa)生馬氏(shi)(shi)體組織轉變時,立即轉入(ru)冷卻能(neng)力(li)弱的(de)介質(zhi)中(zhong)繼(ji)續冷卻。淬(cui)(cui)(cui)火(huo)(huo)(huo)設備(bei)廠家(jia)一般用(yong)水作為(wei)快(kuai)冷卻淬(cui)(cui)(cui)火(huo)(huo)(huo)介質(zhi),用(yong)油作為(wei)慢(man)冷淬(cui)(cui)(cui)火(huo)(huo)(huo)介質(zhi),有時可(ke)以采用(yong)水淬(cui)(cui)(cui)、空冷的(de)方(fang)法(fa)。雙介質(zhi)淬(cui)(cui)(cui)火(huo)(huo)(huo)可(ke)以更好的(de)防止(zhi)工(gong)件(jian)變形開裂。尺(chi)寸較大(da)的(de)碳素鋼工(gong)件(jian)適宜(yi)采用(yong)這(zhe)種(zhong)方(fang)式淬(cui)(cui)(cui)火(huo)(huo)(huo)。
4、分(fen)級(ji)淬(cui)火(huo):這種淬(cui)火(huo)方(fang)法由(you)于工件(jian)(jian)(jian)內外(wai)溫度(du)均勻并在(zai)緩(huan)慢冷(leng)卻(que)條(tiao)件(jian)(jian)(jian)下完成馬氏(shi)轉變,大大減(jian)(jian)少了淬(cui)火(huo)能(neng)力因(yin)而有(you)效(xiao)的(de)減(jian)(jian)少或防止了工件(jian)(jian)(jian)的(de)變形與開裂,同時(shi)淬(cui)火(huo)設備廠家還克服(fu)了雙介(jie)質(zhi)淬(cui)火(huo)出水入油難以(yi)控制的(de)缺點。但這種淬(cui)火(huo)方(fang)法由(you)于冷(leng)卻(que)介(jie)質(zhi)溫度(du)較(jiao)高,工件(jian)(jian)(jian)在(zai)堿浴或鹽浴中的(de)冷(leng)卻(que)速度(du)較(jiao)慢,因(yin)而等溫度(du)時(shi)間又有(you)限(xian)制,大截面零件(jian)(jian)(jian)難以(yi)達到臨(lin)界淬(cui)火(huo)速度(du),分(fen)級(ji)淬(cui)火(huo)只適用于尺(chi)寸較(jiao)小(xiao)的(de)工件(jian)(jian)(jian)。