滲透檢測線廠家講退磁機的退磁方式
一、交流電退磁
a.交(jiao)流(liu)電(dian)退磁(ci)(ci)(ci)(ci)通(tong)過法:對(dui)于(yu)(yu)中小型工(gong)件(jian)的批量退磁(ci)(ci)(ci)(ci),把(ba)工(gong)件(jian)放(fang)在(zai)裝有(you)軌道和拖板的退磁(ci)(ci)(ci)(ci)機上(shang)退磁(ci)(ci)(ci)(ci),退磁(ci)(ci)(ci)(ci)時,將工(gong)件(jian)放(fang)在(zai)拖板上(shang)置于(yu)(yu)線(xian)圈(quan)前30cm處,線(xian)圈(quan)通(tong)電(dian)時,將工(gong)件(jian)沿(yan)著(zhu)軌道緩(huan)慢(man)地從(cong)線(xian)圈(quan)中通(tong)過并遠離(li)線(xian)圈(quan)至少1m以外(wai)(wai)處斷電(dian)。對(dui)于(yu)(yu)不(bu)能放(fang)在(zai)退磁(ci)(ci)(ci)(ci)機上(shang)退磁(ci)(ci)(ci)(ci)的重型或(huo)大型工(gong)件(jian),也可以將線(xian)圈(quan)套在(zai)工(gong)件(jian)上(shang),通(tong)電(dian)時緩(huan)慢(man)地將線(xian)圈(quan)通(tong)過并遠離(li)工(gong)件(jian),至少1m以外(wai)(wai)處斷電(dian)。
b.衰(shuai)減法(fa):由于交流電(dian)(dian)的方向不斷(duan)的換向,故可用(yong)自(zi)動衰(shuai)減退(tui)磁(ci)器或調壓器逐漸降低電(dian)(dian)流為零進行退(tui)磁(ci),如將工(gong)件放在(zai)線圈內(nei)、夾在(zai)探傷機的兩(liang)磁(ci)化夾頭之間、或用(yong)支桿(gan)觸(chu)頭接觸(chu)工(gong)件后(hou)將電(dian)(dian)流遞減到零進行退(tui)磁(ci) 對于大型承壓設備的焊(han)(han)縫(feng),也可用(yong)交流電(dian)(dian)磁(ci)軛退(tui)磁(ci)。將電(dian)(dian)磁(ci)軛兩(liang)極跨(kua)接在(zai)焊(han)(han)縫(feng)兩(liang)側,接通電(dian)(dian)源,讓電(dian)(dian)磁(ci)軛沿焊(han)(han)縫(feng)緩慢移動,當(dang)遠離焊(han)(han)縫(feng)1m以(yi)外再(zai)斷(duan)電(dian)(dian),進行退(tui)磁(ci)。
二(er)、直流電(dian)退(tui)(tui)磁(ci)(ci):直流電(dian)磁(ci)(ci)化過(guo)的工(gong)件(jian)用直流電(dian)退(tui)(tui)磁(ci)(ci),可采(cai)用直流換(huan)向衰減或超低(di)頻電(dian)流自動(dong)退(tui)(tui)磁(ci)(ci)。
a.直流(liu)換向衰(shuai)減(jian)退磁(ci):通過(guo)不斷改變直流(liu)電(dian)(包(bao)括三相全波(bo)整流(liu)電(dian))的方(fang)向,同(tong)時(shi)使(shi)通過(guo)工件的電(dian)流(liu)遞減(jian)到零進行退磁(ci)。電(dian)流(liu)衰(shuai)減(jian)的次數應(ying)盡可能(neng)多(一般要求30次以(yi)上),每次衰(shuai)減(jian)的電(dian)流(liu)幅(fu)度應(ying)盡可能(neng)小(xiao),如(ru)果衰(shuai)減(jian)的幅(fu)度太大,則(ze)達不到退磁(ci)目的。
b.超低(di)頻電流自(zi)動退磁:超低(di)頻通常指頻率(lv)為(wei)0.5~10Hz,可(ke)用于對(dui)三相全波整流電磁化的工件進行退磁。
c.加熱工件(jian)退磁:通(tong)過加熱提高工件(jian)溫度至居里(li)點以上,是有(you)效的(de)退磁方法,但這(zhe)種方法不經濟,也不實用(yong)。