Wire rod mill pass design is an important part of the rolling process. Reasonable pass system and reasonable pass design play an important role in rolling smoothly, improving the production capacity of rolling mill and guaranteeing product quality. There are many pass systems used in wire rod rolling mill. When choosing the pass system, according to the structure and process characteristics of the rolling mill, suitable elongation coefficient can be used to roll wire with good dimension tolerance and surface quality. The selection of the wire rod mill pass system is related to rolling mill type, raw material size, rolling equipment conditions, and production operation conditions.
Roughing and intermediate rolling mills are mostly equipped with horizontal two-roll mills arranged in tandem, and the strength of the mill is high. The rolling process of rough and intermediate rolling mills adopts single or multi-line rolling. Except for the last one or two of the intermediate rolling mills, the pass of each stand is common to all products.
The extended pass system of rough and intermediate rolling mill consisting of odd passes can be used to select the combination pass system of the box (abnormal box) - ellipse (double arc ellipse) - circle - ellipse - circle, or box - ellipse - Square - ellipse - circle.
The extended pass system of rough and medium rolling mill consisting of even passes is the best choice for ellipse-circle-ellipse-circle combined pass system or box-box-ellipse-square-ellipse-circle combined pass system.
Roughing rolling mill is an extended pass system for rough and intermediate rolling of compact rolling mill. The combined pass system of the box (flat) - box (flat) - Hexagon - Square - ellipse - circle should be selected.
In roughing rolling stage, large elongation coefficient 1.3-1.45, compact rolling mill 1.4-1.7 and medium elongation coefficient 1.25-1.38 are adapted for intermediate rolling mill.
Elliptical-circular wire rod mill pass system is widely used in pre-finishing and finishing mills of modern high-speed wire rod mills. The pre-finishing mill generally consists of four stands with an average elongation coefficient of 1.21-1.31. The finishing mill generally consists of 8 to 10 stands, most of which are 10. The average elongation coefficient of the finishing mill is 1.215 to 1.255.