在鍛造和軋制生產(chǎn)中，鋼坯一般在完全燃燒火焰的氧化氣氛中加熱。采用不完全燃燒的還原性火焰（即“自身保護(hù)氣氛”）來(lái)直接加熱金屬，可以達(dá)到無(wú)氧化或少氧化的目的。這種加熱方式稱為明火式或敞焰式無(wú)氧化加熱，成功地應(yīng)用于轉(zhuǎn)底式加熱爐和室式加熱爐。

In forging and rolling production, billets are usually heated in the combustion atmosphere of complete combustion flame. The direct combustion of metal can be achieved by the incomplete combustion of reduced flame (i.e., the "self protective atmosphere"), which can achieve the  of no oxidation or less oxidation. This heating method is called open flame or open flame oxidation free heating, which has been successfully applied to rotary hearth furnace and chamber heating furnace.

連續(xù)加熱爐連續(xù)加熱爐包括推鋼式加熱爐、步進(jìn)式爐、轉(zhuǎn)底式爐、分室式爐等連續(xù)加熱爐，但習(xí)慣上常指推鋼式爐。連續(xù)加熱爐多數(shù)用于軋制前加熱金屬料坯，少數(shù)用于鍛造和熱處理。

It is named according to the varieties of rolling, the type of rolling mill and the nominal size. The principle of "nominal size"

For rolling mills, they are named after the gear ring and the pitch diameter of the herringbone gear.