3. Slitting Rolling Process
The slitting rolling process is primarily used in continuous or semi-continuous bar rolling lines and significantly increases the output of small-diameter rebar. It simplifies billet specifications and pass design, thereby improving mill productivity. Compared to conventional rolling, slitting rolling requires fewer passes to produce the same section of the rolled product.
SME’s slitting technology employs a slitting wheel method suitable for producing rebars with diameters ranging from ø8 mm to ø25 mm. Currently, 2-slit, 3-slit, and 4-slit rolling processes have been successfully and widely applied. Factories typically select the appropriate slitting method based on output requirements and equipment conditions. Some facilities have even produced ø12 mm rebar using a 5-slit rolling process, achieving a yield rate of 97.6%.
4. Pass-Free Rolling Process
Pass-free rolling refers to a process in which flat rollers without engraved grooves are used. The billet undergoes square-to-rectangular deformation to reduce its cross-section, and is then rolled into square, round, flat, or other simple shapes using a reduced number of finishing passes. Compared with traditional groove rolling, the main advantages of pass-free rolling are higher roller utilization and lower production costs.
This technology was initially applied to compact roughing mills using through-type guides. Due to the short spacing between stands, the rolling thrust increases the bite angle of the downstream mill, allowing for significant elongation deformation. However, this design may pose challenges during failure handling, so some mills use rolling guides with guide tips. Pass-free rolling is commonly applied in the production of steel bars and wire rods.
