钢的轧制，是整个轧钢生产过程的核心。坯料通过轧制完成变形过程。轧制工序对产品质量起着决定性作用。轧制产品的质量要求，包括产品的几何形状和尺寸内部***和性能以及产品光洁度三个方面。

The rolling of steel is the core of the whole rolling process. The blanks are rolled to complete the deformation process. The rolling process plays a decisive role in the quality of the product. The quality requirements of rolling products include three aspects, including the internal structure and performance of the geometric and dimensional accuracy of the products and the finish of the products.

从金属学角度来看，热轧与冷轧的界限应该以金属再结晶的温度来区分，即低于再结晶温度的轧制为冷轧；高于再结晶温度的轧制为热轧。而钢的再结晶温度一般在450℃～600℃范围之内。

From the point of view of metallization, the boundary between hot rolling and cold rolling should be distinguished from the temperature of recrystallization of metal, that is, the rolling that is lower than the recrystallization temperature is cold rolling, and the rolling that is higher than the recrystallization temperature is hot rolling. The recrystallization temperature of steel is generally within the range of 450 ~ 600.

棒材精轧件后为什么要采用穿水冷却工艺？（1）提高了产品的力学性能；（4）料型控制不好，或有条头和开花头现象，使切分刀不能顺利切开料型。（2）减少了产品表面二次氧化损失；（3）穿水后，由于轧件温度低，刚度大，在冷床输入辊道上事故减少，轧件在冷床上冷却时塌腰弯曲减少，可以提高成材率和产品质量；（4）冷床长度可相应减少。

Why do we need to wear water cooling technology after finishing bar?

(1) improve the mechanical properties of the product; (2) reduce the two oxidation loss on the surface of the product; (3) after water, because the rolling temperature is low, the stiffness is large, the accident on the roller table of the cold bed is reduced, the bending of the rolled piece in the cold bed is reduced, the yield and quality of the product can be improved; (4) the length of the cold bed can be reduced correspondingly.