A rolling method for strapping steel with a tensile strength of 500mpa

Abstract

The invention relates to a rolling method for strapping steel with a tensile strength of 500 MPa, which is characterized in that the method comprises the following steps: step 1: controlling the oxide scale on the surface of the steel strip; step 2: before producing the strapping steel, a welding machine is used for spotting Experiment; Step 3: Matching reduction ratio of F1 and F2 frames; Step 4: Unit tension control between frames; Step 5: F1‑F4 work roll and intermediate roll bending force control; Step 6: Emulsion iron powder content Control; Step 7: Emulsion edge spray control. This solution can reduce the degree and frequency of CPC deviation, improve the surface quality of the strip, the shape of the rolling mill section and the problems of opening and breaking of the strip, avoid production and equipment accidents, and ensure stable and smooth production.

Description

technical field [0001] The invention relates to a rolling method, in particular to a rolling method for strapping steel with a tensile strength of 500 MPa, which belongs to the field of metal material pressure processing. Background technique [0002] Cold-rolled strapping steel is a strip-shaped steel product that ensures the safe loading, unloading and transportation of goods. The tapping mark of the strapping steel in Meishan Iron and Steel Cold Rolling Plant is AS4160C2, the steel grade is S350GD+AZ, the target content of C is 0.20%, and the target content of Mn is 0.95. %, the tensile strength is 500MPa, the yield strength and tensile strength of the strapping steel are large, the flatness of the head and tail is not good, the surface scale is much scale, the rolling force of the pickling unit in the cold rolling process is large, and the thickness accuracy is required. , the finished product shape control requirements do not exceed 15I, and the steepness is less than 3...

AI Technical Summary

Problems solved by technology

[0006] 2) The strapping steel contains 0.20% carbon, and when the head and tail of the strip steel are exposed to the air, it is easy to produce thick iron oxide scale. The laser welding machine is highly sensitive to the iron oxide scale and carbon content. The strip height difference before and after the seam, false welding or air holes exist, and the weld seam will tear or break when passing through the tension leveler or rolling mill, causing the unit to stop for a long time

[0007] 3) After the high carbon content of the strapping steel, the surface of the strip steel is prone to produce thicker oxide scales. After pickling in the acid tank, the surface of the strip steel is often under pickling, which affects the surface quality of the strip steel and cannot meet customer needs.

[0008] 4) The yield and tensile strength of the bundled strip steel are high, and the head and tail of the hot plate raw material are prone to camber. When the deformation is produced in the rolling mill section, the rolling force of F1 and F2 stands often exceeds 1200 tons, and unilateral or bilateral waves appear. In severe cases, the cavity will be broken and the belt will be broken, which will damage the surface of the work roll and intermediate roll, and even cause the backup roll to stick to steel. The average time to deal with the broken belt and replace the damaged roll is more than one hour. The troubleshooting time is long, and the production and equipment losses are serious.

[0009] 5) The edge is thinned and the strip steel plate is lacking, which cannot meet customer needs;

[0012] One of the common points of many of the above traditional methods is to always focus on the control of the rolling mill itself, but no matter what rolling force and tension distribution scheme is used to adjust, it has a limit defect, because the strap steel itself yields The strength and tensile strength are high, and it is difficult to deform. In many cases, not only the shape of the plate is difficult to control, but also the deviation of the edge size is obvious. In order to overcome the above shortcomings, the present invention proposes a technology different from the above methods, so The main problem to be solved by the disclosed technology is similar to this technology but the technical solution is different from this technology

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