six-high hot rolling mill

six-high hot rolling mill

Technological process:

The bar will use cold billet or hot billet for production. They will be directly hoisted in rows to feeding roller way, then sent to the billet pushing roller way in rows for entering the billet-pushing type heating furnace for heating.

According to the different heating method and heating requirement for different kinds of steel, the billets will be heated to 1100-1200 centidegrees, then sent to roughing rolling mill assembly for rolling via furnace delivery table.

The whole rolling line is composed of 17 stands of rolling mill, including roughing rolling, intermediate rolling and final rolling.

The roughing rolling mill assembly and intermediate rolling assembly consist 11 stands of 2-roller high rigidity rolling mills with one DC motor driving 2 stands. The final rolling assembly is composed of 6 stands of high rigidity short stress line mills among which one stand is horizontal-vertical mill, all driven by DC motors individually. The roughing milling and intermediate milling adopt slight tension rolling for ensuring high quality product. In addition, for the sake of the work pieces getting into the rolling mills and for the sake of easy solving of accidents, before the final rolling assembly, one set of continuous fly shear is equipped to cut the head, tail of the work pieces and cut the work pieces in accidents.

For different kinds of products, the billets are rolled for 9 to 17 times to be 10 or 36 mm round bar, debar or small section steel. The max rolling speed of the finished product is 15m/s.

The debar coming out from the final rolling mill assembly goes through the reinforced bar penetrating-through-cooling-water-device, after on-line heat treatment, is sent to finished product multiple length fly shear for cutting. The water cooling device before the multiple length fly shear and the frequency inverting roller way are both loaded on a mobile carrier that can move transversely. According to production plan, the frequency inverting roller way or water cooling control device can be moved into or out from the position left for them so that super thin steel and alloy steel can be rolled.

The bar cut into multiple length, via cooling bed, is conveyed onto frequency inverting roller way and auto steel loading device for being sent to walking beam type notch-bar cooling bed to be straightened and cooled. At the side near the outlet of the cooling bed, there is a head aligning roller way to align the front end of bars.

After the bar is cooled to around 200 on the cooling bed, they will be collected in rows by a set of steel unloading device installed at the exit of the cooling bed. The cooling beds output roller way will send the bars in rows to the fixed cold shear for conveying chain for steel conveying and inspection. Qualified cut-to-length bar will be packed in bundles, weighed, name plate put and sent into warehouse.

six-high hot rolling mill