Before changing the rollers, it is necessary to double check whether the upper roller is the same as the roller of the changed frame, rolling variety, and specification; Scrub each slide, roll flat head, and inner hole of the sleeve, and apply clean grease after cleaning. After the preparation work is completed, the rack replacement work can be carried out according to the roller replacement plan, and the work steps are:

Turn off the cooling water of the rolling mill and remove the inlet and outlet guides. Remove the water pipe joints of the upper and lower rollers. Start the hydraulic locking device for opening the frame. Select "frame lateral movement" for the horizontal frame to move the frame forward and move the rolling mill to the limit position on the operating side. (Select the "Stand Lift/Lower" button for the vertical rolling mill to lower the stand and lower the rolling mill to the lower limit position.) Pull out the fixed pin of the flat head sleeve bracket wrench, and pull the bracket wrench to separate the flat head of the stand from the flat head sleeve bracket. Pull the "rack lateral movement" button of the horizontal rolling mill to move the flat head sleeve bracket backwards, detach the flat head sleeve from the rolling mill flat head, and move the flat head sleeve bracket to the limit position on the transmission side (pull the vertical rolling mill button to raise the flat head sleeve bracket, detach the flat head sleeve from the rolling mill flat head, lift the flat head sleeve bracket to the limit position on the transmission side, and then pull the "rack lateral movement" button to move the vertical rolling mill to the outer limit position). Lift the frame as a whole from the rolling line using a crane. Place the new roller frame as a whole on the sliding roller, and use a sled to rotate the roller so that the flat head of the roller matches the position of the flat head sleeve of the rotating shaft. After confirming that the rolling mill frame is aligned with the rolling line, pull the "frame lateral movement" button of the horizontal rolling mill to move the flat head sleeve bracket laterally towards the operating side (pull the "frame lateral movement" button of the vertical rolling mill to move the frame backward and move the vertical rolling mill to the inner limit position. Then pull the "frame lifting/lowering" button of the vertical rolling mill to lower the flat head sleeve bracket). Insert the flat head of the rolling mill into the drive shaft flat head sleeve until it reaches the limit position. Start the locking device to lock the frame and connect the water pipe joint. Install the guide., And fine adjust the roll gap and guide of the rolling mill