Reducing Mill

China Reducing and Sizing Mill Introduction

Recent years, Modern high speed wire rod manufacturing technology is developing in the following trends, high rolling speed, high efficiency, no twist and micro tension combination, high accuracy, according to many years experience, our company digest the high tech aboard, we develop our own Reducing and Sizing Mill (RSM) manufacturer which makes us the first and best company in china who made RSM.

Reducing and sizing mill designing concept

The whole set of machine has the following advantages, high speed, well controlled, high accuracy rolling, whole set exchangeable, two reducing mills and two sizing mills is assembled right behind the finishing mill, by using the extension of RSM, the speed of 8 finishing mill stands are much lower, which also reduce the raise of temperature from the high speed wire rod zone, by this we can achieve high speed low temperature rolling, ensure the finial product mechanical property.

The RSM is located right between the finishing mill and laying head, the material cool down rapidly in the big water tank, so that we can control the temperature of material into the RSM, use hot machine rolling tech to improve the inside structure of wire rod, enhance the mechanical property and surface quality.

We use the traditional oval- circle type system for the whole production line groove design, the material surface can be flexibly adjusted cause the RSM has significant reduction rate, then remarkably reduce the roll and collars storage, simplified the collars management, reduce the exchanging times, enhance rolling efficiency.

The final products through the RSM, are with high accuracy, the dimensional tolerance is assured around ±0.1 mm, ovality is around 60% of the whole declination.

The main characteristic of reducing and sizing mill.

The RSM is composed of 4 cantilever type rolling mills, allocated by V type, the first two are reducing mill, the last two are sizing mill, using, oval-round-round-round groove system, which can achieve high accuracy products, the RSM is driven by a AC motor gearbox, which has 9 clutches, when rolling difference products, can switch the clutch position, can satisfy different technology requirements, with designing of reasonable roll gaps, can ensure micro tension rolling for RSM, which ensure the high accuracy final products.

Reducing mill max rolling power is 330 KN, sizing mill max rolling power is 130 KN, the biggest designing speed is 140m/s, ensured rolling speed is 112m/s,for satisfy the high speed rolling requirement, sizing mill use compact design, two sizing mill has 150mm center distance, small triangle guide is assembled between two sizing mills, which reduce risk of steel piling, and also avoid machine shutting down because of rolling guide made roller bear damaged, to ensure the rolling accuracy, sizing mill has roller adjusting and hydraulic devices, can adjust the rolling line. 

Advantage of Reducing and Sizing Machine Technique  

1. Increase the machine production

The design speed of RSM is 140 m/s ,ensure the speed up to 110 m / s or more,exit speed of RSM basically stable up to100m/s,

Thus, the use of RSM technology can significantly increase the speed of the small size of the finishing product, thereby increasing the small size of the product machine production.

For example, Φ5.5mm wire finish rolling speed increased from 85m / s to 110 m / s, its mill-hour output can be increased to 30%.Especially for small size products accounted for a higher proportion of total production, the production line can significantly increase or decrease the mill's annual loading rate.

2. Low-temperature high speed and Controlled rolling

RSM average rolling with low temperature of 750 ℃ ~ 800 ℃, in order to meet the requirements of controlled rolling γ + α two-phase region, which can effectively refine the grain size and improve the performance of wire products.Compared with the corresponding allowable rolling force with the previous design of the finishing mill finished stand greatly improved, reducing mill, sizing mill respectively 330 kN, 130 kN.

3. Free rolling specifications

Using RSM technology can be certain specification range of free size rolling (without roll change can produce Φ5.25 mm, Φ5.75 mm and other special specifications of the products through the roll gap adjustment), thereby expanding the product specifications range, to meet the special requirements of users on the wire size. Products designed grade differential is 0.5 mm.

4. Simplifying the pass system

Since reducing mill has a large reduction ratio, rolling section can be flexibly adjusted appropriately, which greatly simplifies the rough rolling, intermediate rolling, pre-finishing and finishing mill pass system.

5. Improving product precision

As a result of sizing machine,can be achieved precise rolling, the wire product size tolerance control ± 0.1 mm or less, ovality size is 60% of the total deviation, which for downstream metal products deep processing and standard production users extremely favorable.

6. Increasing the metal yield

After using reducing sizing rolling units, products dimensional accuracy is improved, Overall length dimensional accuracy uniformity better , Reduce the amount of loss can cut the head and tail portions of the ultra-poor, to effectively improve the metal recovery rate.

7. Improve operation efficiency of rolling mill

Due to simplify the pass system and improve the pass commonality, significantly reducing the amount of roll change when change specifications, the main rolling specifications of replacement focused on reducing sizing machine. Reducing sizing unit uses a set of special hydraulic disassembling tool to quickly change the reducing sizing mill collars,that is convenient and efficient.Reducing sizing mill can also use the  quick-change collar device, the standby unit can pre-heating offline and install the collars,all of the fluid medium and detection signals are concentrated in the quick connection plate, and the use of quick-release type gear couplings, to achieve online quick-change operations. Thereby, greatly reducing the collars changing time, improve mill operating rate.

8. Improve product competitiveness

For normal wire rod, using reducing sizing mill technology can achieve cold rolling , can achieve product performance same as  micro-alloying, so which can replace the micro-alloying process, thus,saving alloy material, effectively reduce production costs. For special wire rod,through the "free sizing" products with the precise dimensional tolerances, and after controlled rolling and cooling process to obtain fine grain structure, can reduce pickling dipping, drawing and annealing processes when drawing the cold heading steel and quality bearing steel,save raw materials and reduce costs. In addition,using the reducing sizing mill technology can also accommodate small multiple standard rolling plan,to ensure that in the case of frequently changing specifications still ensure highly yields and  flexibility to adapt to marketing demand.

Reducing sizing mill technology parameters

Wire rod rolling specifications：Φ5.5~Φ16mm

Rolling speed：110m

Rolling force allowed：

reducing dia. 330KN，sizing dia. 130KN

Roller shaft dia：

reducing dia. 230mm，sizing dia. 150mm

Rolling temperature：≥750℃

Wire rod rolling specifications：Φ5.5~Φ16mm

Rolling speed：110m

Rolling force allowed：

Reducing dia. 330KN，sizing dia. 130KN

Roller shaft dia：

Reducing dia. 230mm，sizing dia. 150mm

Rolling temperature：≥750℃