At present, high-speed wire fineRollerThe machine is generally composed of 8 to 10 rolling mills. The rolling force and impact force of each rolling mill are different. With the increase of rolling passes, the rotation speed of the roll ring will be greatly increased, and the wear of the roll ring will also increase. Therefore, the rolling force is selected for each rolling mill. When the material is used, the impact force and wear resistance of each rolling mill should be fully considered. Otherwise, improper material selection will lead to roll collapse during finish rolling, and the cause of roll collapse is not easy to be identified. For each rolling mill in finish rolling, due to the large cross-sectional size and deformation of the rolled piece, the rolling load and the large impact force on the front stand roll ring, the roll rings of the first few rolling mills of the finish rolling mill should be made of materials with high strength index and good thermal fatigue resistance, and the wear resistance index should be ranked second; however, the rolling load and impact force of the rear frame roll ring are small, so the wear resistance and thermal fatigue resistance of the roll ring should be given priority.

FineRollerShaking of internal rolled pieces and stacking of steel during the process:

1. Poor roller matching of roller ring

The high-speed wire rod mill has strict requirements for the finishing inner roll ring, because the high-speed wire rod finishing mill is collectively rotated by a 6000 kW variable frequency AC speed regulation main motor, and the gear transmission ratio between each frame is fixed and cannot be changed. It is impossible to adjust the speed of a unit. The finishing mill is required not only to meet the gear transmission ratio between the frames, but also to meet the outer diameter error of the same pass secondary roll ring ± 0.05mm. At the same time, the roller diameter of any circular workpiece frame is not allowed to be smaller than that of the previous frame. If the roller diameter of the elliptical workpiece is larger than the previous round hole roller, the rolled workpiece will vibrate between the two stands, resulting in steel stacking between the two stands. During the steel stacking process, the heat of the rolled workpiece is transferred to Two roller rings cause the temperature of the roller ring to rise and the thermal stress is concentrated. After sudden water supply, the roller ring will break due to the large temperature difference between the water temperature and the roller ring.

2. Poor roll gap setting

Due to the strict requirements on the roll matching of the inner roll ring in the finish rolling, the operators are required to set the roll gap of each stand in strict accordance with the roll gap value specified in the process specification during the finish rolling, so as to reduce the steel stacking caused by the poor setting of the roll gap between the stands, and reduce the increase of the probability of the roll ring fracture caused by the impact on the roll ring and the thermal stress concentration caused by the steel stacking, so as to ensure the smooth production.

3. Poor size of final rolled parts

Rolling parts leave pre-finishingRollerAfter the mill, the impact force on the roll ring of a rolling mill of the finishing roll mill becomes larger and the deformation becomes larger. Due to the poor size of the rolled pieces, especially the large size of the rolled pieces at the same time, the rolling force becomes larger. It also increases the rolling force of the first few rolling mills of the finishing mill, resulting in an increase in the jitter of the rolled pieces between the first few rolling mills and the probability of ring breakage of the first few rolling mills of the finishing mill. Therefore, the shape and size of the entry into the finishing mill should be strictly controlled so that it is as close as possible to the size required by the rolling procedure. The size of the inlet section of the non-twist finishing mill is very important. Ideally, they should be kept between ± 1% and ± 1.5 of the standard value.