Hot Roll Forming Technology of Shaped Square Steel

Hot Roll Forming Technology of Shaped Square Steel

The flat anchor plate of the bridge industry made of SCR440 steel 49mmx51mm pointed angle shaped square steel is neither square steel nor flat steel. The shape of this special-shaped square steel is strict, the hot-rolling forming is very difficult, the technical difficulty is large, and the product has no corresponding standard for reference. At present, there is no hot rolling mill directly rolling molding in China, and only cold drawn can be used, or flat steel bar can be rolled and cut into this size. However, cold drawn molding has low production and high cost, which hinders its development and progress. When the shaped squar steel bar is rolled into flat steel, the symmetry is not good on both sides, and the cutting cost is high and the production time is long. If it can be produced through the rolling process, it will be a revolutionary material molding process improvement. Through many trials and improvements, Glory Steel has been able to roll 49x51mm shaped square steel, which has been recognized and praised by users. Glory Steel is a specialized flat steel production line that can produce flat steel of various specifications.

Non-porous rolling belongs to single-section hole rolling. Because it is simple without support and protection of the hole type, the process parameters are very strict, the adjustment is difficult and the shape control is difficult. The products produced by the non-porous type have complex width and no strong regularity because of no hole type limited. According to the user’s requirements for the flat steel anchor plate, all four faces must be leveled in order to locate the drilling process. If the drilling is offset, the stress of flat anchor is not uniform during using process, which has great effect on the service life. Therefore, how to keep the four faces flat, reduce the side drum shape, and reduce the drum width is the key to the successful rolling of 49x51mm shaped square steel. Due to the difference in friction between the contact surface of the roll and the rolling mill, and the difference between the geometry and size of the deformation zone, the flow trajectory of the metal dots along the contact surface is different from the area near the contact surface and the distance away from the contact surface.

The height ratio of 49x51mm shaped square steel is 96.1%, which is equal to 1 but not equal to 1. It is difficult to produce by open hole type in the rolling process. The best way is to use non-porous rolling, but how to control in rolling the side of the arc to ensure a flat shape, the key is to reduce the width of the drum.

By reducing the rolling temperature, the iron oxide scale of the rolled product is washed away, the rolling speed is appropriately increased, and the surface roughness of the roll is lowered, and the surface protrusion is also improved. It is feasible to produce SCR40 series 49mmx51mm shaped square steel by a non-porous rolling process on a hot rolling mill. Controlling the drum shape in the key to rolling this similar shaped steel with very close width and thickness. The focus of reducing the drum width is the distribution of the reduction amount. If the reduction can be reduced as much as possible in the finishing pass, it is very advantageous to control the flatness of the product.