閉口式機(jī)架為一整體鑄件制成。當(dāng)厚度偏差增大（在板寬方向上厚度不同）導(dǎo)致在材料設(shè)計(jì)后產(chǎn)品損失中應(yīng)考慮增加板厚邊緣。這種機(jī)架形式在型鋼車間中小型軋機(jī)上應(yīng)用較多。其優(yōu)點(diǎn)是強(qiáng)度和剛度較高，輥跳值較小，產(chǎn)品精度較高。其主要缺點(diǎn)是制造比較困難，裝卸、換輥不方便。軋制壓力較大、對(duì)軋件尺寸要求比較嚴(yán)格時(shí)常采用閉口式機(jī)架。如初軋機(jī)、型鋼連軋機(jī)和型鋼成品軋機(jī)等。

The closed frame is made of a whole castings. This type of frame is used more in the small and medium mill in the steel workshop. Its advantages are that the strength and stiffness are high, the roll jump value is small and the precision of the product is high. Its main disadvantage is that it is difficult to manufacture, and it is inconvenient to load and load and change the roll. When the rolling pressure is larger and the requirements for the size of the rolled piece are strict, the closed frame is often used. Such as the early rolling mill, the type steel continuous rolling mill and the steel finished rolling mill, etc.

軋機(jī)專業(yè)廠家說，熱軋機(jī)的優(yōu)點(diǎn)主要可以歸納為三個(gè)方面。一點(diǎn)，采用熱軋可以明顯的減少能耗，降低成本。此外，熱軋時(shí)可以發(fā)揮出較高的金屬塑性，而且所產(chǎn)生的變形抗力較小，能夠有效的防止金屬出現(xiàn)嚴(yán)重的變形問題。

The mill manufacturer explains that the advantages of the hot rolling mill can be summed up in three aspects. First, the use of hot rolling can significantly reduce energy cumption and reduce costs. In addition, hot rolling can give full play to the high metal plasticity, and the deformation resistance is small, which can effectively prevent the serious deformation of the metal.

使用熱軋的第二個(gè)優(yōu)點(diǎn)就在于其可以適當(dāng)?shù)母纳平饘僖约昂辖鸩牧系募庸すに囆阅?。也就是說，其可以把較大的晶粒進(jìn)行破碎，同時(shí)可以減少裂紋的出現(xiàn)，這樣一來，也就相當(dāng)于減少了鑄造過程中的缺陷問題，提高合金的加工性能。

The second advantage of hot rolling is that it can appropriately improve the processing performance of metal and alloy materials. That is to say, it can break the larger grain and reduce the appearance of the crack, which is equivalent to reducing the defects in the casting process and improving the processing performance of the alloy.