3. Slitting Rolling Process
The slitting rolling is mostly used in bar continuous or semi-continuous rolling lines, and can greatly increase output of small-size rebar. This rolling process simplifies billet specifications and pass design, improves mill output, for the same section of the rolled part, comparing normal rolling process, the number of rolling passe is less than normal rolling process.
SME’s slitting technology is to use the slitting wheel method that is appropriate for production of ø8mm-ø25mm rebar. Currently 2 slitting, 3slitting and 4slitting rolling process has mature and good application. The factories common combines output requirements and equipment condition of the production line to select proper slitting technology. Some factories have produced ?12mm rebar by 5 slitting rolling way and its yield is 97.6%.
4. Pass-free Rolling Process
The pass-free rolling refers to the flat roller without engraved grooves, through the square-rectangular deformation process the section is reduced to a certain degree, then rolled into a square, round, flat and other simple sections through a smaller number of finishing hole patterns. Compared with the traditional groove rolling, the biggest advantage of pass-free rolling technology is the high utilization rate of rollers and lower production cost.
The pass-free rolling was first applied on compact roughing mill, using through type guides, due to the short stand spacing, with the rolling thrust to increase the downstream mill bite angle, can obtain a large extension deformation. Because this design has some influences when handling failure, thus some rolling mills adopt rolling guides with guide tips. The pass-free rolling technology is applied to the steel bar and wire rod production line.
