这些应力沿辊身的散布是不均匀的、不断改变的，其原因不只有规划要素，还有轧辊在运用中磨损、温度和辊形的不断改变。

The dispersion of these stresses along the roll is uneven and ctantly changing, and the reas are not only the planning elements, but also the ctant change of wear, temperature and roll shape in the use of the rolls.

被轧制的钢种  

被轧制的钢种是选择轧辊的关键因素，其抗变形能力随坯料化学成分不同而改变，主要表现在轧制的各阶段变形的负荷大小和变化。必须根据确定的强度和硬度选择轧辊。  

Rolled steel

The rolled steel is the key factor to select the roll. Its deformation resistance varies with the chemical  of the billet. It is mainly manifested in the load and change of deformation in each rolling stage. The roll must be selected according to the determined strength and hardness.

轧机布置和道次设计  

机架在生产线的位置以及道次设计对轧辊的选择有很大影响。根据机架位置，轧辊的受力方式和性能可以有很大变化。这是因为应用于粗轧机架和精轧机架的轧辊有非常不同的受力方式，从而导致轧辊性能有预期的改变.

Rolling mill layout and pass design

The of the rack in the production line and the design of the pass h***e great influence on the choice of the roll. According to the  of the frame, the force and performance of the roller can be greatly changed. This ibecause the rolls used in roughing mill stand and finishing mill stand h***e very different forces, resulting in expected changes in roll performance.